×
Log in to StudySoup
Get Full Access to UH - BIOL 1361 - Study Guide
Join StudySoup for FREE
Get Full Access to UH - BIOL 1361 - Study Guide

Already have an account? Login here
×
Reset your password

UH / Biology / BIOL 1361 / Describe how secretory proteins are transported through the endomembra

Describe how secretory proteins are transported through the endomembra

Describe how secretory proteins are transported through the endomembra

Description

School: University of Houston
Department: Biology
Course: Introduction to Biology
Professor: Cheek
Term: Summer 2015
Tags:
Cost: 50
Name: Comprehensive Final Study Guide Bio 1361
Description: It's Dr. Cheek review guide with my compiled answer. i hope you guys find it useful
Uploaded: 12/06/2015
36 Pages 63 Views 12 Unlocks
Reviews


1


Describe how secretory proteins are transported through the endomembrane system and the sequence of organelles through which they pass.



COMPREHENSIVE FINAL EXAM BIOL 1361

Chapters 1 – 8, 32 - 37

Chapter 1

Explain the theme of emergent properties as it applies to the levels of the  biological hierarchy  

New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and  interactions of parts as complexity increases

Distinguish between hypotheses and predictions in the scientific method

Chapter 2: Chemical Context of Life

Compare and contrast the different types of chemical bonds and define the terms  chemical bond, covalent bond (including polar and nonpolar), ionic bond, and  hydrogen bond.  


Describe the role of atp in coupling exergonic and endergonic reactions in a cell.



o Chemical bond: attraction between two atoms, resulting from a sharing of outer shell electrons or the  presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells 

o Covalent bond: sharing a pair of valence electrons by two atoms

• Nonpolar covalent bond (Cl2) : electrons are shared equally because the two atoms have the  same electronegativity 

• Polar covalent bond (H20) : when a atom is bonded to a more electronegative atom, the electrons  are not shared equally

o Ionic bond (NaCl) : Chemical bond resulting from the attraction between oppositely charged ions 

o Hydrogen bond (btw O & H of 2 water mlcs): type of weak chemical bond that is formed when the  slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly  negative atom of a polar covalent bond in another molecule or in another region of the same molecule


Explain the specific function of chlorophyll in photosynthesis.



Explain the four emergent properties of water and their significance to life.  1. Cohesive behavior 

2. Ability to moderate temperature  Don't forget about the age old question of How did mehmet conquer constantinople?

3. Expansion upon freezing 

4. Versatility as a solvent

2

Identify which properties of water are due to hydrogen bonds and explain how

The properties of water arise from attractions between oppositely charged atoms of different water  molecules: 

• The slightly positive hydrogen of one molecule is attracted to the slightly negative oxygen of a  nearby molecule

• The two molecules are held by a hydrogen bond 

• In liquid form, hydrogen bonds are very fragile 

Hydrogen bonding organizes water molecules into a higher level of structural order

Explain why water is considered a polar solvent.  

­Ions and regions of the water molecules are attracted to each other owing to their opposite charges  ­Oxygen regions of the water molecules are negatively charged and are attracted to sodium cations  ­Hydrogen regions are positively charged and are attracted to chloride anions  If you want to learn more check out What flower does myth say that the lacandon gods were born from?

­Result: water molecules surround the individual sodium and chloride ions, separating and shielding  them from one another 

Identify the kinds of substances to which water is or is not attracted. Hydrophobic 

• Substances that are non­ionic and nonpolar (cannot form hydrogen bonds) repel water  • Oil 

Hydrophilic

• Substance that has an affinity for water 

• Cotton, cellulose

Define the terms hydrophilic and hydrophobic and state which correctly describes  ions, polar, and nonpolar substances

Hydrophobic 

• Substances that are nonionic and nonpolar (cannot form hydrogen bonds) repel water  Hydrophilic

• Substance that has an affinity for water

3

Chapter 3: Carbon and Molecular Diversity of Life

Describe and recognize the structure of functional groups, including hydroxyl,  carbonyl, carboxyl, amino, sulfhydryl, and phosphate  

Hydroxyl (­OH)

­Name: alcohols 

­Properties: polar, forms H bonds 

Phosphate (PO4)

­Name: organic phosphates

­Properties: strong potential to react with water & release energy, negative charge, acidic, reactive Amino (­NH2)

­Name: amines, amino acids Don't forget about the age old question of For whom will they be produced?

­Properties: act as a base, attracts protons [+H]

Sulfhydryl (­SH)

­Name: thiol

­Properties: can form disulfide bridge (­S­S­)

Methyl (­CH3)

­Name: methylated compounds 

­Properties: reduces reactivity of compounds, nonpolar  

Carbonyl (C=O)

­Name: ketones & aldehydes 

­Properties: polar, found in many sugars 

Carboxyl (COOH)

­Name: Carboxylic acids, organic acids 

­Properties: acts as an acid

­Protons (H+) released in aqueous solution

Describe the properties of each functional group and the significance of those  properties

Identify the type of macromolecules based on a structural diagram  

Compare the structure and function of different types of lipids: triglycerides,  phospholipids, steroids, and saturated and unsaturated fatty acids.

Phospholipids: 

∙ Glycerol + 2 fatty acids + phosphate + choline

4

∙ Joined by ester linkage (O­C=O)

∙ Formed by dehydration (condensation) 

Fats (Triglycerides) 

∙ Saturated fatty acid: We also discuss several other topics like What is the content of the 8th amendment?

o Hydrocarbon chain has all single bonds  Don't forget about the age old question of What is chauvet cave?

o Side chain pack tightly 

o Solid at room temp

∙ Unsaturated Fatty Acid: 

o >1 double bond (cause a kink)

o cant pack tightly 

Steroid (Cholesterol, estrogen, testosterone) 

Differentiate among primary, secondary, tertiary, and quartenary protein structure, and identify the types of bonds contributing to each.

Primary­Amino acid sequence (held by peptide bond)

Secondary ­Alpha helices & Beta pleated sheets

­Form due to hydrogen bonding between O and H of amino acid backbone (N­C­C­N­C­C) ­Bond: hydrogen bond

Tertiary ­ 3D structure, vverall shape of a polypeptide resulting from the folding and interaction of  side chains with each other  

­Bonds: ­Covalent bond­disulfide bridges 

­Hydrophobic interaction: as a polypeptide folds into its functional shape, amino acids with  hydrophobic (nonpolar) side chains usually ends up in clusters at the core of the protein out of  contact with water

Quaternary ­Protein structure with 2 or more polypeptides

e.g: insulin, collagen (3 strings bound together)  & hemoglobin Don't forget about the age old question of Liberalism refers to what?

Chapter 4: Tour of the Cell

Compare and contrast the structures of prokaryotic versus eukaryotic cells. Prokaryotic

• Domain: Bacteria, archaea

• No nucleus 

• DNA is concentrated in the nucleoid 

• 1­5 micrometer in diameter

Eukaryotic

5

• Domain: protists, fungi, animals and plants 

• DNA is located in the nucleus 

• Larger than prokaryotic cells 

• 10­100 micromemter in diameter

Describe the key characteristics and functions of the following organelles: nucleus  (including nucleolus), endoplasmic reticulum (including smooth vs. rough), Golgi  apparatus, lysosome, mitochondrion, chloroplast

Nucleus 

• Contains majority of the genes 

• Contains nuclear envelope, nuclear lamina, nucleolus 

Smooth ER

• Synthesis of lipids: fatty acids, phospholipids, fats, steroids 

• Detoxification of drugs and poisons 

• Storage of calcium ions 

• Enzymes help with lipid synthesis 

Rough ER

• Site of protein synthesis

• Proteins produced by the ribosomes attached to the ER 

Lysosome

• Vesicles (sacs of membrane) filled with enzymes that digest biomolecules

• Dispose of cellular debris and worn out organelles

• Works best to in acidic environment

• Made by rough ER then transferred to the Golgi for further processing 

Golgi apparatus

• After leaving the ER, transport vesicles travel to Golgi 

• Products of the ER (ex. Proteins) are modified or stored then rewrapped in vesicles to other  destinations ­ cell membrane or secretion outside cell

• Consists of cisternae 

• Manufactures macromolecules 

• External molecules on the membrane have "docking sites" on the surface of specific organelles  Mitochondria

• Sites for cellular respiration

6

• Uses oxygen to generate ATP by extracting energy from sugars, fats and other fuels  Chloroplasts 

• Sites of photosynthesis

• Solar energy converted to chemical energy by absorbing sunlight and using it drive the synthesis of  organic compounds

Describe how secretory proteins are transported through the endomembrane  system, and the sequence of organelles through which they pass.

1. Rough ER synthesizes proteins

2. Proteins made in rough ER are wrapped in vesicles 

3. Vesicles fused with Golgi & delivers

4. Within Golgi, proteins are modified or store, then rewrapped in vesicles to travel to final  destination­cell membrane or secretion outside the cell Pg. 78

Chapter 5: Membrane Transport and Cell Signaling

Explain the structural basis of selective permeability of plasma membranes.  Predict how a molecule would be transported across the phospholipid bilayer, if  given the molecule’s polarity and size

­Only certain substances are allowed to cross the membrane

­Depends on the discriminating barrier of the lipid bilayer and the specific transport proteins built into the membrane

Explain how animal and plant cells behave when put in solutions hypotonic or  hypertonic to the cell. Use knowledge of how diffusion and osmosis depend on  relative solute and water concentration in 2 compartments separated by a  selectively permeable membrane

Hypotonic: 

• Solution has a lower solute concentration than the cell so water moves into the cell causing plant  cells to swell and animal cells to swell and burst

Hypertonic:

 • The solution has a higher solute concentration than the cell so the water moves out of the cell and  into the solution causing the cell to plasmolyze

Isotonic: 

• Concentration of solutes is equal inside and outside the cell so water moves across the membrane in  both directions maintaining cell size

7

Compare and contrast membrane transport processes: passive transport, active  transport, co-transport, simple diffusion, facilitated diffusion

­Passive transport: Diffusion of a substance across a biological membrane without expending energy 

­Facilitated Diffusion: Polar molecules and ions stopped by the lipid bilayer of the membrane diffuse  passively with the help of transport proteins that span the membrane 

• Protein can transport the solute in either direction, but the net movement is down the  concentration gradient of the solute 

­Co­transport: a single ATP powered pump that transports a specific solute can indirectly drive the  active transport of several other solutes in this mechanism

• It is powered by ATP 

­Active transport: Requires ATP

• Can pump substances form low to high concentration

• Cell actively maintains internal environment different from external environment ­Diffusion

• Movement of particles of any substance so that they spread out into available space

Chapter 6: Metabolism

Define the following terms: activation energy, catalyst, enzyme, substrate, active  site, and induced fit. Use these terms to describe the interaction of an enzyme  and its substrate.  

Active site 

• Part of enzyme that grabs substrate 

Substrate

• Reactants specific for a particular enzyme

Catalyst

• Chemical agent that increases the rate of a reaction without being consumes by the reaction

Describe the role of the ATP in coupling exergonic and endergonic reactions in a  cell.  

­ATP powers cellular work by coupling exergonic reaction to endergonic reaction • Chemical work: pushing of endergonic reactions that would not occur spontaneously  • ATP transfers a PO4 group to a reactant 

• Reactant can now react more easily with another molecules

• New chem bonds forms

­Transport work: pumping of substances across membranes against the direction of spontaneous  movement

• For transport & mechanical work:

• ATP transfers a PO 4 group to a transport or contractile protein

• Protein changes shape

• Solute moves or muscle proteins move

8

­Mechanical work: the contraction of muscle cells and the movement of chromosomes during cellular  production

­Energy coupling: the use of an exergonic process to drive an endergonic one

­ATP is responsible for mediating most energy coupling in cells and acts as the immediate source of  energy that powers cellular work

­Pg 122

Define the following terms: competitive inhibitor, noncompetitive inhibitor,  allosteric regulation, cooperativity, and feedback inhibition. Predict how low or  high concentration of a final product could change concentration of an  intermediate if the final product inhibits one of the early reactions in a metabolic  pathway.

­Cofactors: 

• Non protein helpers for catalytic activity that are bundled tightly to the enzyme as a permanent  resident or bound loosely and reversibly along with the substrate

∙ Mcls that must be present w the enz so it can interact w substrate: 

metal ions: Mg, Se, Fe, Co

organic compounds: vitamins (esp vit B) 

­Competitive inhibitors:

• Reduce the productivity of enzymes by blocking substrates from entering active sites  • Can be overcome by increasing the concentration of substrate so that as active sites become  available, more substrate molecules that inhibitor molecules are around to gain entry to the sites ­Noncompetitive inhibitors:

• Do not directly compete with the substrate to bind to the enzyme at the active site • They impede enzymatic reactions by binding to another part of the enzyme which causes the  enzyme molecule to change its shape on such a way that the active site becomes less effective at  catalyzing the conversion of substrate to product 

­Allosteric inhibitors:

• Attaches to another region of the enzyme 

• Changes enzyme shape so active site no longer grabs substrate

Chapter 7: Cellular Respiration and Fermentation

o i l r i g: oxidation is loss (of electrons), reduction is gain (of electrons) lose electrons, become oxidized => e donor [glucose -> to pyruvate] gain electrons, become reduced => e acceptor [NAD+ -> NADH]  

Explain how NAD+ and FAD serve as electron carriers when they are reduced, and  how these reduction reactions are coupled to oxidation reactions during cellular  respiration.  

­FADH2 and NADH donate electron's to the transport proteins in the inner mitochondrial membrane ­NAD+ → NADH, electron donated then regenerated in fermentation

­FAD → FADH

Contrast the ATP yield from NADH versus FADH2

9

­The amount of ATP made by electrons from an NADPH molecule is greater than the amount made  by electrons from an FADH2 molecule

­Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron  donor than when NADH is the electron donor

Describe the initial reactants and final products of glycolysis.

Inputs: glucose, ADP, NAD+

Outputs: 2 pyruvate, 2ATP (2ATP spent), 2NADH

Describe the inputs and outputs of the citric acid cycle and explain why this  process is called a cycle.

Inputs: ADP, NAD+, acetyl CoA

Outputs: (1ATP, 3NADH, 2CO2, 1FADH2)x2, coenzyme A

Acetyl CoA formation: pyruvate is oxidized to CO2, NAD+ -> NADH, FAD (e  carrier) -> FADH2

Coenzyme A -> acetyl CoA  

State the stage or stages of cellular respiration during which each of the following  is produced: CO2, NADH, H+, FADH2, ATP

CO2• Citric acid cycle 

NADH• Glycolysis • Citric acid cycle 

H+• Proton motive force 

FADH2• Citric acid cycle 

ATP• Glycolysis • Citric acid cycle

Explain the movement of electrons and/or protons (as appropriate) in the electron  transport chain, chemiosmosis, proton motive force, and oxidative  phosphorylation. Describe how each process is linked to the process that  precedes it and to the process that follows it in the sequence of cellular  respiration reactions.  

Oxidative phosphorylation consists of 2 processes ­ electron transport and ATP synthesis. 

In electron transport, the NADH and FADH2 produced in the first three stages of cellular respiration  are oxidized by O2 (the oxidative part of this stage). These redox reactions also drive the pumping  of protons across the inner mitochondrial membrane, creating a proton ( H+) gradient. 

This H+ gradient is used to power the chemiosmotic synthesis of ATP from ADP and Pi (the  phosphorylation part of this stage).

10

Describe how ATP synthase uses the proton motive force to synthesize ATP. State  where in the mitochondrion ATP synthesis occurs.

Describe the fermentation reactions that occur after glycolysis, including which  molecules are oxidized, which are reduced, and what the products are.

­ Input: 2NADH, 

­ Output: 2NAD+, ethanol/lactate, 2ATP

­ Pyruvate, the end product, serves as an electron acceptor for oxidizing NADH back to NAD+,  which can be reused in glycolysis

­ Occurs when O2 is not present

a. Fermentation is used in the absence of oxygen to produce ATP. 

b. Alcohol fermentation: pyruvate is converted to ethanol in two steps. First step releases carbon dioxide from the pyruvate, which is converted to the two­carbon compound acetaldehyde. In the  second step, NADH reduces acetaldehyde to ethanol. This regenerates the supply of NAD+ needed for continuation of glycolysis. 

c. Lactic acid fermentation: pyruvate is reduced directly by NADH to form lactate as an end product  with no release of CO2.

Chapter 8: Photosynthesis  

Compare and contrast the light reactions and the Calvin cycle in terms of location  within the chloroplast, inputs, and outputs.  

o Location

• Light reaction occurs in the thylakoid of the chloroplast

• Calvin Cycle occurs in the stroma

o Product 

• Light reaction: ATP, NADPH, O2

• Calvin cycle: glucose, ADP, NADP+

Explain the relationship between the light reactions and the Calvin cycle.

By producing NADPH and ATP, light reaction helps the Calvin cycle. The Calvin cycle uses ATP  and NADPH to reduce CO2 to sugar and then produces ADP and NADP+. The cycle goes on

Explain the specific function of chlorophyll in photosynthesis.  

The chlorophyll is found in the thylakoid membrane. Chlorophyll is the pigment that absorbs in red  and blue and reflects green, which makes plants look green. Chlorophyll captures the sun's energy  and is used as energy to complete the photosynthesis process (light dependent reaction.)

Describe the role of the following in linear electron flow: Photosystem II,  Photosystem I, H2O, primary electron acceptor, electron transport chain, and  NADP+.

11

Compare the process of chemiosmosis during cellular respiration versus during  photosynthesis. Include the source of electrons, the location of the electron  transport chain, the role of the proton-motive force, the location of ATP synthase, and the location of high and low proton concentrations within the mitochondrion  or chloroplast.

Describe the role of NADP+ during photosynthesis including its reduction during  the light reactions and the subsequent oxidation of NADPH during the Calvin  cycle  

Chapter 33: Animal Nutrition  

Explain the function of tight junctions in epithelia in relation to digestion and  absorption  

Without tight junctions,  

• Hydrochloric acid might attack epithelial cells

• Enzymes might digest epithelial cell proteins  

Structure:  

• Plasma membranes of neighboring cells bound together by proteins  • Form a continuous seal around cell  

• Separate outside fluids from inside body

Explain how structure of the intestinal lining enhances surface area

Large folds in the lining are studded with villi. Each epithelial cell of a villus has  microvilli that are exposed to the intestinal lumen. Together, the folds, the villi  and microvilli have a large surface area to increase the rate of nutrient  absorption

Trace transfer of biomolecules from intestine into blood or lymph and into organs  

-Ex: sugar fructose moves by facilitated diffusion down its concentration gradient  from the lumen into the epithelial cells. From there, fructose exits the basal  surface and is absorbed into microscopic vessels or capillaries at the core of  each villus.

-The capillaries and veins that carry nutrient rich blood away from the villi  converge into hepatic portal vein, a blood vessel that leads directly to the liver.  From the liver, blood travels to the heart and then to other tissues and organs.

Label a graph of blood glucose concentration over time, including axis labels and  indicating when the stimulus for blood glucose increase occurs, when insulin  secretion occurs, when glucagon secretion occurs, when negative feedback is  occurring, and when the set point is reached (notebook)

Chapter 34: Gas Exchange & Circulation

12

Explain how each variable in the diffusion rate equation affects gas diffusion rate

Qs=DA(C2-C1/x)(t) 

• Qs=quantity of substance  

• (C2-C1)= large concentration difference  

• x= thin ----small  

How will Qs change if the value of each variable is large • D=increases

• A=increases  

• C2-C1= increases

• x=decreases  

• t=increases  

How will Qs change if the value of each variable is small  • D=decreases  

• A=decreases  

• C2-C1=decreases  

• x=increases  

• t=decreases An increase in concentration difference across a cell membrane  enhances Q

Explain how properties of respiratory surfaces affect gas diffusion rate  

-The moistness prevents cell membrane from collapsing and the plasma membrane must be in contact with an aqueous solution

13

-The rate of diffusion is proportional to the surface area across which it occurs and  inversely proportional to the square of the distance through which molecules  must move  

-Gas exchange is fast when the area for diffusion is large and the path for diffusion  is short

Explain how cooperativity enhances hemoglobin O2 loading at high O2  concentration and O2 unloading at low O2 concentration and interpret a graph of hemoglobin oxygen binding

Hemoglobin binds O2 reversibly, loading O2 on the lungs and unloading it into  other parts of the body -When O2 binds to one subunit, the other change shape slightly, increasing their affinity for O2-A slight change in PO2 causes  hemoglobin to load or unload a substantial amount of O2-Low pH decreases the  affinity of hemoglobin for O2 (Bohr effect)

Compare the structure of arteries, veins, and capillaries in terms of tissue layers  present and size of each layer

Veins: 3 layers:  

• Outer: connective tissues & elastin  

• Middle: muscle & elastin  

• Inner: endothelial cells

 • Returns blood to heart  

Arteries 3 layers:  

• Outer: connective tissue & elastin  

• Middle: muscle & elastin  

• Inner: endothelial cells

 • Carries blood away from heart

b. Both have two layers of tissue surrounding the endothelium.  

c. Arteries: walls are thick and strong. Walls also have elastic recoil that help  maintain blood pressure and flow to capillaries.  

d. Veins: do not have thick walls. Has a wall only about a third thick as that of an  artery. Contains valves which maintain a unidirectional flow of blood

14

Predict the effect of slow flow rate on diffusion rate across capillary walls, using  Fick’s Law of Diffusion  

-Flow rate depends on the cross-section of the pipe

 -Total area of capillaries is very large (Great total cross-sectional area) -Flow rate is slower in capillaries  

-Allows time for diffusion

Chapter 32.1: Thermoregulation and Homeostasis  

List and describe 4 physical mechanisms of heat exchange. Relate to animal’s  source of body heat.

4 mechanisms of heat exchange:  

∙ Conduction: direct transfer heat btw objects in contact

∙ Convection: heat transfer by fluid flow (breeze/ water flow)

∙ Radiation: electromagnetic radiation coming from objects warmer than  absolute 0 (infrared: most animals)

∙ Evaporation: liquid mlc w enough kinetic energy to escape as gas,  departing high energy mlcs to remove heat.

Animals’ source of body heat:  

Endotherm (inner) vs Ectotherm (external)

Interpret a figure showing counter-current exchange of heat between blood  vessels entering and exiting an appendage.

15

Chapter 32.3: Osmoregulation (done) 

Label a graph showing osmoregulation and osmoconformity across a range of  external osmolarities

Identify the biomolecules from which nitrogenous waste is generated  Protein and nucleic acid breakdown

Compare the advantages and disadvantages of ammonia, urea, and uric acid  Ammonia 

• Very toxic b/c its ion

• Interferes with oxidative phosphorylation 

• Can only be tolerated in small concentrations

• Animals need access to lots of water

• Most common in aquatic species 

Urea 

• Synthesized from NH3 by vertebrate liver

• Less toxic than NH3

• Requires less H2O to excrete than NH3

• Mammals, adults amphibians, sharks, some marine fish 

16

• Expends energy

Uric acid 

• Low toxicity 

• Excreted as paste 

• Conserves H2O 

• Birds, reptiles, insects, land snails 

• Expends energy

Chapter 32.2: Endocrine system (done) 

Describe the pathway of long distance signaling, including endocrine cell,  hormone, means of delivery, and target cell  

­Hormone is secreted­Enters bloodstream 

­Travels to target cell in another part of body ­­­­­­­­Control of pH in in the duodenum  • As the contents of the stomach enter the duodenum, the low pH acts as a stimulus for S cells  • The stimulated S cells secrete the hormone secretin into the bloodstream 

• Circulating secretin reaches target cells in the pancreas

• Target cells in the pancreas respond by releasing bicarbonate into ducts leading into the duodenum  • The release of bicarbonate raises the pH in the duodenum, neutralizing the stomach acid

Compare similarities and differences between pathways of local and long distance  signaling  

­Local signaling 

• Paracrine signaling: secreting cell acts on nearby target cells by discharging molecules of a local  regulator into the extracellular fluid 

• Synaptic signaling: nerve cell releases neurotransmitter molecules into a synapse, stimulating the  target cell 

• Signaling cell secretes messenger molecules, which only travel short distances ­ Long distance: 

• Endocrine: specialized endocrine secrete cells secrete hormones into body fluids, often blood.  Hormones reach virtually all body cells but are bound by only some cells 

• Travels in bloodstream

Pheromones: secreted by cells in individual to act on cells in another individual of the same species

Compare signal reception between plasma membrane receptors and intracellular  receptors, particularly receptor location and type of ligand

17

Chapter 37: Neurons (done) 

Draw a motor neuron, labeling the dendrites, cell body, axon, and axon terminals,  indicating where a stimulus is detected, where an action potential is initiated,  and where the action potential travels to the target cell  

Explain how resting potential is generated, including the transport proteins  required, the ions transported and the ratio at which Na+ and K+ are  transported  

­Generated because of Na+ & K+ movement 

­Ion movement through 3 membrane proteins

­Na+ K+ pump: 3 Na+ out, 2 K+ in

­[Na+]=15 mM inside; 150 mM outside

­[K+]=140 mM inside; 5 mM outside 

­Passive K+ channels ­Passive Na+ channels

Explain the changes in ion movement that initiate and propagate an action  potential, including the role of voltage-gated Na+ channels, voltage-gated K+  channels, sodium-potassium pump, passive Na+ channels, and passive K+  channels

Resting state:  

• The gated Na+ and K+ are closed.  

Ungated channels maintain the resting potential  

Depolarization:

• A stimulus opens some sodium channels.  

Na+ inflow through those channels depolarizes the membrane. If the  depolarization reaches the threshold, it triggers an action potential  

Rising phase of action potential:  

• Depolarization opens most sodium channels, while the potassium channels  remain closed. Na+ influx makes the inside of the membrane positive with  respect to the outside  

Falling phase of the action potential:

18

• Most sodium channels became inactivated, blocking Na+ inflow. Most  potassium channels open, permitting K+ outflow, which makes the inside of  the cell negative again  

Undershoot:  

• The sodium channels close but some potassium channels are still open. As  these potassium channels close and the sodium channels become  unblocked (though still closed) the membrane returns to its resting state

Predict the effect of altered ion permeability on resting or action potentials

Chapter 36: Reproduction & Development  

Compare asexual and sexual reproduction with respect to the type or types of cell  division that support each  

Sexual reproduction requires the fusion of male and female gametes, forming  a diploid zygote (23 paris of chromosomes)  

Internal and external

Asexual reproduction is the production of offspring without gamete fusion  

Mechanism: budding (new from old outgrow: corals), fission (parent split into 2), fragmentation with regeneration (2 step - body split in worm),  parthenogenesis (eggs developed without being fertilized)  

Describe how fertilization forms 2N zygote from 1N eggs & sperm

Fertilization : fusion of male (sperm) & female (egg) gametes (each haploid) to  form a diploid zygote.

1

COMPREHENSIVE FINAL EXAM BIOL 1361

Chapters 1 – 8, 32 - 37

Chapter 1

Explain the theme of emergent properties as it applies to the levels of the  biological hierarchy  

New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and  interactions of parts as complexity increases

Distinguish between hypotheses and predictions in the scientific method

Chapter 2: Chemical Context of Life

Compare and contrast the different types of chemical bonds and define the terms  chemical bond, covalent bond (including polar and nonpolar), ionic bond, and  hydrogen bond.  

o Chemical bond: attraction between two atoms, resulting from a sharing of outer shell electrons or the  presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells 

o Covalent bond: sharing a pair of valence electrons by two atoms

• Nonpolar covalent bond (Cl2) : electrons are shared equally because the two atoms have the  same electronegativity 

• Polar covalent bond (H20) : when a atom is bonded to a more electronegative atom, the electrons  are not shared equally

o Ionic bond (NaCl) : Chemical bond resulting from the attraction between oppositely charged ions 

o Hydrogen bond (btw O & H of 2 water mlcs): type of weak chemical bond that is formed when the  slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly  negative atom of a polar covalent bond in another molecule or in another region of the same molecule

Explain the four emergent properties of water and their significance to life.  1. Cohesive behavior 

2. Ability to moderate temperature 

3. Expansion upon freezing 

4. Versatility as a solvent

2

Identify which properties of water are due to hydrogen bonds and explain how

The properties of water arise from attractions between oppositely charged atoms of different water  molecules: 

• The slightly positive hydrogen of one molecule is attracted to the slightly negative oxygen of a  nearby molecule

• The two molecules are held by a hydrogen bond 

• In liquid form, hydrogen bonds are very fragile 

Hydrogen bonding organizes water molecules into a higher level of structural order

Explain why water is considered a polar solvent.  

­Ions and regions of the water molecules are attracted to each other owing to their opposite charges  ­Oxygen regions of the water molecules are negatively charged and are attracted to sodium cations  ­Hydrogen regions are positively charged and are attracted to chloride anions 

­Result: water molecules surround the individual sodium and chloride ions, separating and shielding  them from one another 

Identify the kinds of substances to which water is or is not attracted. Hydrophobic 

• Substances that are non­ionic and nonpolar (cannot form hydrogen bonds) repel water  • Oil 

Hydrophilic

• Substance that has an affinity for water 

• Cotton, cellulose

Define the terms hydrophilic and hydrophobic and state which correctly describes  ions, polar, and nonpolar substances

Hydrophobic 

• Substances that are nonionic and nonpolar (cannot form hydrogen bonds) repel water  Hydrophilic

• Substance that has an affinity for water

3

Chapter 3: Carbon and Molecular Diversity of Life

Describe and recognize the structure of functional groups, including hydroxyl,  carbonyl, carboxyl, amino, sulfhydryl, and phosphate  

Hydroxyl (­OH)

­Name: alcohols 

­Properties: polar, forms H bonds 

Phosphate (PO4)

­Name: organic phosphates

­Properties: strong potential to react with water & release energy, negative charge, acidic, reactive Amino (­NH2)

­Name: amines, amino acids

­Properties: act as a base, attracts protons [+H]

Sulfhydryl (­SH)

­Name: thiol

­Properties: can form disulfide bridge (­S­S­)

Methyl (­CH3)

­Name: methylated compounds 

­Properties: reduces reactivity of compounds, nonpolar  

Carbonyl (C=O)

­Name: ketones & aldehydes 

­Properties: polar, found in many sugars 

Carboxyl (COOH)

­Name: Carboxylic acids, organic acids 

­Properties: acts as an acid

­Protons (H+) released in aqueous solution

Describe the properties of each functional group and the significance of those  properties

Identify the type of macromolecules based on a structural diagram  

Compare the structure and function of different types of lipids: triglycerides,  phospholipids, steroids, and saturated and unsaturated fatty acids.

Phospholipids: 

∙ Glycerol + 2 fatty acids + phosphate + choline

4

∙ Joined by ester linkage (O­C=O)

∙ Formed by dehydration (condensation) 

Fats (Triglycerides) 

∙ Saturated fatty acid:

o Hydrocarbon chain has all single bonds 

o Side chain pack tightly 

o Solid at room temp

∙ Unsaturated Fatty Acid: 

o >1 double bond (cause a kink)

o cant pack tightly 

Steroid (Cholesterol, estrogen, testosterone) 

Differentiate among primary, secondary, tertiary, and quartenary protein structure, and identify the types of bonds contributing to each.

Primary­Amino acid sequence (held by peptide bond)

Secondary ­Alpha helices & Beta pleated sheets

­Form due to hydrogen bonding between O and H of amino acid backbone (N­C­C­N­C­C) ­Bond: hydrogen bond

Tertiary ­ 3D structure, vverall shape of a polypeptide resulting from the folding and interaction of  side chains with each other  

­Bonds: ­Covalent bond­disulfide bridges 

­Hydrophobic interaction: as a polypeptide folds into its functional shape, amino acids with  hydrophobic (nonpolar) side chains usually ends up in clusters at the core of the protein out of  contact with water

Quaternary ­Protein structure with 2 or more polypeptides

e.g: insulin, collagen (3 strings bound together)  & hemoglobin

Chapter 4: Tour of the Cell

Compare and contrast the structures of prokaryotic versus eukaryotic cells. Prokaryotic

• Domain: Bacteria, archaea

• No nucleus 

• DNA is concentrated in the nucleoid 

• 1­5 micrometer in diameter

Eukaryotic

5

• Domain: protists, fungi, animals and plants 

• DNA is located in the nucleus 

• Larger than prokaryotic cells 

• 10­100 micromemter in diameter

Describe the key characteristics and functions of the following organelles: nucleus  (including nucleolus), endoplasmic reticulum (including smooth vs. rough), Golgi  apparatus, lysosome, mitochondrion, chloroplast

Nucleus 

• Contains majority of the genes 

• Contains nuclear envelope, nuclear lamina, nucleolus 

Smooth ER

• Synthesis of lipids: fatty acids, phospholipids, fats, steroids 

• Detoxification of drugs and poisons 

• Storage of calcium ions 

• Enzymes help with lipid synthesis 

Rough ER

• Site of protein synthesis

• Proteins produced by the ribosomes attached to the ER 

Lysosome

• Vesicles (sacs of membrane) filled with enzymes that digest biomolecules

• Dispose of cellular debris and worn out organelles

• Works best to in acidic environment

• Made by rough ER then transferred to the Golgi for further processing 

Golgi apparatus

• After leaving the ER, transport vesicles travel to Golgi 

• Products of the ER (ex. Proteins) are modified or stored then rewrapped in vesicles to other  destinations ­ cell membrane or secretion outside cell

• Consists of cisternae 

• Manufactures macromolecules 

• External molecules on the membrane have "docking sites" on the surface of specific organelles  Mitochondria

• Sites for cellular respiration

6

• Uses oxygen to generate ATP by extracting energy from sugars, fats and other fuels  Chloroplasts 

• Sites of photosynthesis

• Solar energy converted to chemical energy by absorbing sunlight and using it drive the synthesis of  organic compounds

Describe how secretory proteins are transported through the endomembrane  system, and the sequence of organelles through which they pass.

1. Rough ER synthesizes proteins

2. Proteins made in rough ER are wrapped in vesicles 

3. Vesicles fused with Golgi & delivers

4. Within Golgi, proteins are modified or store, then rewrapped in vesicles to travel to final  destination­cell membrane or secretion outside the cell Pg. 78

Chapter 5: Membrane Transport and Cell Signaling

Explain the structural basis of selective permeability of plasma membranes.  Predict how a molecule would be transported across the phospholipid bilayer, if  given the molecule’s polarity and size

­Only certain substances are allowed to cross the membrane

­Depends on the discriminating barrier of the lipid bilayer and the specific transport proteins built into the membrane

Explain how animal and plant cells behave when put in solutions hypotonic or  hypertonic to the cell. Use knowledge of how diffusion and osmosis depend on  relative solute and water concentration in 2 compartments separated by a  selectively permeable membrane

Hypotonic: 

• Solution has a lower solute concentration than the cell so water moves into the cell causing plant  cells to swell and animal cells to swell and burst

Hypertonic:

 • The solution has a higher solute concentration than the cell so the water moves out of the cell and  into the solution causing the cell to plasmolyze

Isotonic: 

• Concentration of solutes is equal inside and outside the cell so water moves across the membrane in  both directions maintaining cell size

7

Compare and contrast membrane transport processes: passive transport, active  transport, co-transport, simple diffusion, facilitated diffusion

­Passive transport: Diffusion of a substance across a biological membrane without expending energy 

­Facilitated Diffusion: Polar molecules and ions stopped by the lipid bilayer of the membrane diffuse  passively with the help of transport proteins that span the membrane 

• Protein can transport the solute in either direction, but the net movement is down the  concentration gradient of the solute 

­Co­transport: a single ATP powered pump that transports a specific solute can indirectly drive the  active transport of several other solutes in this mechanism

• It is powered by ATP 

­Active transport: Requires ATP

• Can pump substances form low to high concentration

• Cell actively maintains internal environment different from external environment ­Diffusion

• Movement of particles of any substance so that they spread out into available space

Chapter 6: Metabolism

Define the following terms: activation energy, catalyst, enzyme, substrate, active  site, and induced fit. Use these terms to describe the interaction of an enzyme  and its substrate.  

Active site 

• Part of enzyme that grabs substrate 

Substrate

• Reactants specific for a particular enzyme

Catalyst

• Chemical agent that increases the rate of a reaction without being consumes by the reaction

Describe the role of the ATP in coupling exergonic and endergonic reactions in a  cell.  

­ATP powers cellular work by coupling exergonic reaction to endergonic reaction • Chemical work: pushing of endergonic reactions that would not occur spontaneously  • ATP transfers a PO4 group to a reactant 

• Reactant can now react more easily with another molecules

• New chem bonds forms

­Transport work: pumping of substances across membranes against the direction of spontaneous  movement

• For transport & mechanical work:

• ATP transfers a PO 4 group to a transport or contractile protein

• Protein changes shape

• Solute moves or muscle proteins move

8

­Mechanical work: the contraction of muscle cells and the movement of chromosomes during cellular  production

­Energy coupling: the use of an exergonic process to drive an endergonic one

­ATP is responsible for mediating most energy coupling in cells and acts as the immediate source of  energy that powers cellular work

­Pg 122

Define the following terms: competitive inhibitor, noncompetitive inhibitor,  allosteric regulation, cooperativity, and feedback inhibition. Predict how low or  high concentration of a final product could change concentration of an  intermediate if the final product inhibits one of the early reactions in a metabolic  pathway.

­Cofactors: 

• Non protein helpers for catalytic activity that are bundled tightly to the enzyme as a permanent  resident or bound loosely and reversibly along with the substrate

∙ Mcls that must be present w the enz so it can interact w substrate: 

metal ions: Mg, Se, Fe, Co

organic compounds: vitamins (esp vit B) 

­Competitive inhibitors:

• Reduce the productivity of enzymes by blocking substrates from entering active sites  • Can be overcome by increasing the concentration of substrate so that as active sites become  available, more substrate molecules that inhibitor molecules are around to gain entry to the sites ­Noncompetitive inhibitors:

• Do not directly compete with the substrate to bind to the enzyme at the active site • They impede enzymatic reactions by binding to another part of the enzyme which causes the  enzyme molecule to change its shape on such a way that the active site becomes less effective at  catalyzing the conversion of substrate to product 

­Allosteric inhibitors:

• Attaches to another region of the enzyme 

• Changes enzyme shape so active site no longer grabs substrate

Chapter 7: Cellular Respiration and Fermentation

o i l r i g: oxidation is loss (of electrons), reduction is gain (of electrons) lose electrons, become oxidized => e donor [glucose -> to pyruvate] gain electrons, become reduced => e acceptor [NAD+ -> NADH]  

Explain how NAD+ and FAD serve as electron carriers when they are reduced, and  how these reduction reactions are coupled to oxidation reactions during cellular  respiration.  

­FADH2 and NADH donate electron's to the transport proteins in the inner mitochondrial membrane ­NAD+ → NADH, electron donated then regenerated in fermentation

­FAD → FADH

Contrast the ATP yield from NADH versus FADH2

9

­The amount of ATP made by electrons from an NADPH molecule is greater than the amount made  by electrons from an FADH2 molecule

­Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron  donor than when NADH is the electron donor

Describe the initial reactants and final products of glycolysis.

Inputs: glucose, ADP, NAD+

Outputs: 2 pyruvate, 2ATP (2ATP spent), 2NADH

Describe the inputs and outputs of the citric acid cycle and explain why this  process is called a cycle.

Inputs: ADP, NAD+, acetyl CoA

Outputs: (1ATP, 3NADH, 2CO2, 1FADH2)x2, coenzyme A

Acetyl CoA formation: pyruvate is oxidized to CO2, NAD+ -> NADH, FAD (e  carrier) -> FADH2

Coenzyme A -> acetyl CoA  

State the stage or stages of cellular respiration during which each of the following  is produced: CO2, NADH, H+, FADH2, ATP

CO2• Citric acid cycle 

NADH• Glycolysis • Citric acid cycle 

H+• Proton motive force 

FADH2• Citric acid cycle 

ATP• Glycolysis • Citric acid cycle

Explain the movement of electrons and/or protons (as appropriate) in the electron  transport chain, chemiosmosis, proton motive force, and oxidative  phosphorylation. Describe how each process is linked to the process that  precedes it and to the process that follows it in the sequence of cellular  respiration reactions.  

Oxidative phosphorylation consists of 2 processes ­ electron transport and ATP synthesis. 

In electron transport, the NADH and FADH2 produced in the first three stages of cellular respiration  are oxidized by O2 (the oxidative part of this stage). These redox reactions also drive the pumping  of protons across the inner mitochondrial membrane, creating a proton ( H+) gradient. 

This H+ gradient is used to power the chemiosmotic synthesis of ATP from ADP and Pi (the  phosphorylation part of this stage).

10

Describe how ATP synthase uses the proton motive force to synthesize ATP. State  where in the mitochondrion ATP synthesis occurs.

Describe the fermentation reactions that occur after glycolysis, including which  molecules are oxidized, which are reduced, and what the products are.

­ Input: 2NADH, 

­ Output: 2NAD+, ethanol/lactate, 2ATP

­ Pyruvate, the end product, serves as an electron acceptor for oxidizing NADH back to NAD+,  which can be reused in glycolysis

­ Occurs when O2 is not present

a. Fermentation is used in the absence of oxygen to produce ATP. 

b. Alcohol fermentation: pyruvate is converted to ethanol in two steps. First step releases carbon dioxide from the pyruvate, which is converted to the two­carbon compound acetaldehyde. In the  second step, NADH reduces acetaldehyde to ethanol. This regenerates the supply of NAD+ needed for continuation of glycolysis. 

c. Lactic acid fermentation: pyruvate is reduced directly by NADH to form lactate as an end product  with no release of CO2.

Chapter 8: Photosynthesis  

Compare and contrast the light reactions and the Calvin cycle in terms of location  within the chloroplast, inputs, and outputs.  

o Location

• Light reaction occurs in the thylakoid of the chloroplast

• Calvin Cycle occurs in the stroma

o Product 

• Light reaction: ATP, NADPH, O2

• Calvin cycle: glucose, ADP, NADP+

Explain the relationship between the light reactions and the Calvin cycle.

By producing NADPH and ATP, light reaction helps the Calvin cycle. The Calvin cycle uses ATP  and NADPH to reduce CO2 to sugar and then produces ADP and NADP+. The cycle goes on

Explain the specific function of chlorophyll in photosynthesis.  

The chlorophyll is found in the thylakoid membrane. Chlorophyll is the pigment that absorbs in red  and blue and reflects green, which makes plants look green. Chlorophyll captures the sun's energy  and is used as energy to complete the photosynthesis process (light dependent reaction.)

Describe the role of the following in linear electron flow: Photosystem II,  Photosystem I, H2O, primary electron acceptor, electron transport chain, and  NADP+.

11

Compare the process of chemiosmosis during cellular respiration versus during  photosynthesis. Include the source of electrons, the location of the electron  transport chain, the role of the proton-motive force, the location of ATP synthase, and the location of high and low proton concentrations within the mitochondrion  or chloroplast.

Describe the role of NADP+ during photosynthesis including its reduction during  the light reactions and the subsequent oxidation of NADPH during the Calvin  cycle  

Chapter 33: Animal Nutrition  

Explain the function of tight junctions in epithelia in relation to digestion and  absorption  

Without tight junctions,  

• Hydrochloric acid might attack epithelial cells

• Enzymes might digest epithelial cell proteins  

Structure:  

• Plasma membranes of neighboring cells bound together by proteins  • Form a continuous seal around cell  

• Separate outside fluids from inside body

Explain how structure of the intestinal lining enhances surface area

Large folds in the lining are studded with villi. Each epithelial cell of a villus has  microvilli that are exposed to the intestinal lumen. Together, the folds, the villi  and microvilli have a large surface area to increase the rate of nutrient  absorption

Trace transfer of biomolecules from intestine into blood or lymph and into organs  

-Ex: sugar fructose moves by facilitated diffusion down its concentration gradient  from the lumen into the epithelial cells. From there, fructose exits the basal  surface and is absorbed into microscopic vessels or capillaries at the core of  each villus.

-The capillaries and veins that carry nutrient rich blood away from the villi  converge into hepatic portal vein, a blood vessel that leads directly to the liver.  From the liver, blood travels to the heart and then to other tissues and organs.

Label a graph of blood glucose concentration over time, including axis labels and  indicating when the stimulus for blood glucose increase occurs, when insulin  secretion occurs, when glucagon secretion occurs, when negative feedback is  occurring, and when the set point is reached (notebook)

Chapter 34: Gas Exchange & Circulation

12

Explain how each variable in the diffusion rate equation affects gas diffusion rate

Qs=DA(C2-C1/x)(t) 

• Qs=quantity of substance  

• (C2-C1)= large concentration difference  

• x= thin ----small  

How will Qs change if the value of each variable is large • D=increases

• A=increases  

• C2-C1= increases

• x=decreases  

• t=increases  

How will Qs change if the value of each variable is small  • D=decreases  

• A=decreases  

• C2-C1=decreases  

• x=increases  

• t=decreases An increase in concentration difference across a cell membrane  enhances Q

Explain how properties of respiratory surfaces affect gas diffusion rate  

-The moistness prevents cell membrane from collapsing and the plasma membrane must be in contact with an aqueous solution

13

-The rate of diffusion is proportional to the surface area across which it occurs and  inversely proportional to the square of the distance through which molecules  must move  

-Gas exchange is fast when the area for diffusion is large and the path for diffusion  is short

Explain how cooperativity enhances hemoglobin O2 loading at high O2  concentration and O2 unloading at low O2 concentration and interpret a graph of hemoglobin oxygen binding

Hemoglobin binds O2 reversibly, loading O2 on the lungs and unloading it into  other parts of the body -When O2 binds to one subunit, the other change shape slightly, increasing their affinity for O2-A slight change in PO2 causes  hemoglobin to load or unload a substantial amount of O2-Low pH decreases the  affinity of hemoglobin for O2 (Bohr effect)

Compare the structure of arteries, veins, and capillaries in terms of tissue layers  present and size of each layer

Veins: 3 layers:  

• Outer: connective tissues & elastin  

• Middle: muscle & elastin  

• Inner: endothelial cells

 • Returns blood to heart  

Arteries 3 layers:  

• Outer: connective tissue & elastin  

• Middle: muscle & elastin  

• Inner: endothelial cells

 • Carries blood away from heart

b. Both have two layers of tissue surrounding the endothelium.  

c. Arteries: walls are thick and strong. Walls also have elastic recoil that help  maintain blood pressure and flow to capillaries.  

d. Veins: do not have thick walls. Has a wall only about a third thick as that of an  artery. Contains valves which maintain a unidirectional flow of blood

14

Predict the effect of slow flow rate on diffusion rate across capillary walls, using  Fick’s Law of Diffusion  

-Flow rate depends on the cross-section of the pipe

 -Total area of capillaries is very large (Great total cross-sectional area) -Flow rate is slower in capillaries  

-Allows time for diffusion

Chapter 32.1: Thermoregulation and Homeostasis  

List and describe 4 physical mechanisms of heat exchange. Relate to animal’s  source of body heat.

4 mechanisms of heat exchange:  

∙ Conduction: direct transfer heat btw objects in contact

∙ Convection: heat transfer by fluid flow (breeze/ water flow)

∙ Radiation: electromagnetic radiation coming from objects warmer than  absolute 0 (infrared: most animals)

∙ Evaporation: liquid mlc w enough kinetic energy to escape as gas,  departing high energy mlcs to remove heat.

Animals’ source of body heat:  

Endotherm (inner) vs Ectotherm (external)

Interpret a figure showing counter-current exchange of heat between blood  vessels entering and exiting an appendage.

15

Chapter 32.3: Osmoregulation (done) 

Label a graph showing osmoregulation and osmoconformity across a range of  external osmolarities

Identify the biomolecules from which nitrogenous waste is generated  Protein and nucleic acid breakdown

Compare the advantages and disadvantages of ammonia, urea, and uric acid  Ammonia 

• Very toxic b/c its ion

• Interferes with oxidative phosphorylation 

• Can only be tolerated in small concentrations

• Animals need access to lots of water

• Most common in aquatic species 

Urea 

• Synthesized from NH3 by vertebrate liver

• Less toxic than NH3

• Requires less H2O to excrete than NH3

• Mammals, adults amphibians, sharks, some marine fish 

16

• Expends energy

Uric acid 

• Low toxicity 

• Excreted as paste 

• Conserves H2O 

• Birds, reptiles, insects, land snails 

• Expends energy

Chapter 32.2: Endocrine system (done) 

Describe the pathway of long distance signaling, including endocrine cell,  hormone, means of delivery, and target cell  

­Hormone is secreted­Enters bloodstream 

­Travels to target cell in another part of body ­­­­­­­­Control of pH in in the duodenum  • As the contents of the stomach enter the duodenum, the low pH acts as a stimulus for S cells  • The stimulated S cells secrete the hormone secretin into the bloodstream 

• Circulating secretin reaches target cells in the pancreas

• Target cells in the pancreas respond by releasing bicarbonate into ducts leading into the duodenum  • The release of bicarbonate raises the pH in the duodenum, neutralizing the stomach acid

Compare similarities and differences between pathways of local and long distance  signaling  

­Local signaling 

• Paracrine signaling: secreting cell acts on nearby target cells by discharging molecules of a local  regulator into the extracellular fluid 

• Synaptic signaling: nerve cell releases neurotransmitter molecules into a synapse, stimulating the  target cell 

• Signaling cell secretes messenger molecules, which only travel short distances ­ Long distance: 

• Endocrine: specialized endocrine secrete cells secrete hormones into body fluids, often blood.  Hormones reach virtually all body cells but are bound by only some cells 

• Travels in bloodstream

Pheromones: secreted by cells in individual to act on cells in another individual of the same species

Compare signal reception between plasma membrane receptors and intracellular  receptors, particularly receptor location and type of ligand

17

Chapter 37: Neurons (done) 

Draw a motor neuron, labeling the dendrites, cell body, axon, and axon terminals,  indicating where a stimulus is detected, where an action potential is initiated,  and where the action potential travels to the target cell  

Explain how resting potential is generated, including the transport proteins  required, the ions transported and the ratio at which Na+ and K+ are  transported  

­Generated because of Na+ & K+ movement 

­Ion movement through 3 membrane proteins

­Na+ K+ pump: 3 Na+ out, 2 K+ in

­[Na+]=15 mM inside; 150 mM outside

­[K+]=140 mM inside; 5 mM outside 

­Passive K+ channels ­Passive Na+ channels

Explain the changes in ion movement that initiate and propagate an action  potential, including the role of voltage-gated Na+ channels, voltage-gated K+  channels, sodium-potassium pump, passive Na+ channels, and passive K+  channels

Resting state:  

• The gated Na+ and K+ are closed.  

Ungated channels maintain the resting potential  

Depolarization:

• A stimulus opens some sodium channels.  

Na+ inflow through those channels depolarizes the membrane. If the  depolarization reaches the threshold, it triggers an action potential  

Rising phase of action potential:  

• Depolarization opens most sodium channels, while the potassium channels  remain closed. Na+ influx makes the inside of the membrane positive with  respect to the outside  

Falling phase of the action potential:

18

• Most sodium channels became inactivated, blocking Na+ inflow. Most  potassium channels open, permitting K+ outflow, which makes the inside of  the cell negative again  

Undershoot:  

• The sodium channels close but some potassium channels are still open. As  these potassium channels close and the sodium channels become  unblocked (though still closed) the membrane returns to its resting state

Predict the effect of altered ion permeability on resting or action potentials

Chapter 36: Reproduction & Development  

Compare asexual and sexual reproduction with respect to the type or types of cell  division that support each  

Sexual reproduction requires the fusion of male and female gametes, forming  a diploid zygote (23 paris of chromosomes)  

Internal and external

Asexual reproduction is the production of offspring without gamete fusion  

Mechanism: budding (new from old outgrow: corals), fission (parent split into 2), fragmentation with regeneration (2 step - body split in worm),  parthenogenesis (eggs developed without being fertilized)  

Describe how fertilization forms 2N zygote from 1N eggs & sperm

Fertilization : fusion of male (sperm) & female (egg) gametes (each haploid) to  form a diploid zygote.

Page Expired
5off
It looks like your free minutes have expired! Lucky for you we have all the content you need, just sign up here