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TOWSON / Biology / BIOL 191 / How much elements does matter consist of?

How much elements does matter consist of?

How much elements does matter consist of?


School: Towson University
Department: Biology
Course: Introductory Biology for Health Professions
Professor: Angela cox
Term: Fall 2016
Cost: 50
Name: BIOL 190 Unit 2 Test Review Sheet
Description: These notes cover what is going to be on our next exam
Uploaded: 10/08/2016
21 Pages 171 Views 2 Unlocks

BIOL 190

How much elements does matter consist of?

Professor Angela M. Cox

Unit Exam #2 Test Review Sheet

Lecture 1 (9/20/16) – Chemistry

∙ Matter

o What everything is made of

o Atoms – Tiny pieces of matter

o Elements – Different kinds of atoms

 Hydrogen, oxygen, carbon

o Compounds – Two (or more) kinds of atoms stuck together  Water, Methane

o Anything that occupies space and has mass

 States of matter: Solid, liquid, gas

o Composed of elements

 92 occurring elements

 25 essential to life

∙ Oxygen, carbon, hydrogen, nitrogen

∙ Calcium, phosphorus, potassium, sulfur,  

How are molecules held together?

sodium, chlorine, magnesium

∙ 14 trace elements

o Elements combine to form compounds

 Compounds have different characteristics than their  elements

o Atoms made of protons (+), neutrons, and electrons (-)  Protons and neutrons in nucleus

∙ Atoms We also discuss several other topics like What happens to cells and organelles when there is cell fractionation?

o Smallest unit of matter that till retains the properties of an  element

o Composed of subatomic particles

 Proton – Single unit of positive charge

 Electron – Single unit of negative charge

 Neutron - Neutral

o Protons and neutrons in nucleus – Have nearly identical  mass (Daltons)

o Electrons – Circle around the nucleus

o Element symbol – Internationally recognized symbol for an  element

What are the characteristics of macromolecules?

o Atomic # - # of protons

o Mass # - # of protons and neutrons

o Mass # – Atomic # = # of neutrons  

∙ Molecule

o A combination of atoms

o Held together with covalent bonds

o Similarities

 All have C and H

 This makes them organic molecules

∙ Chemical Bonding

o Electrons determine how an atom bonds

 Electrons are organized into orbitals If you want to learn more check out What is the formula for energy in a planet?

 Atoms combine to obtain a full outer orbital

∙ Stable (happy) – 8 electrons (except for 2 H) Don't forget about the age old question of Where is the sigmoid flexure?

 Atoms can gain, lose, or share electrons (whatever it  takes to get to a stable state)

∙ Covalent Bonds

o Atoms bonded by sharing electrons

o Electrons spend time around both atoms

o Polar Molecule – Has opposite charges on opposite ends of  the molecule

 Has poles on the molecule (like a magnet)

 Electrons aren’t shared equally – Negatively charged  electrons spend more time around one atom (the O  atom in water)

 Gives this end a negative charge

∙ Ionic Compounds (Salts)

o Ionic Bonds – Attraction between oppositely charged ions  Ions – Atoms with a positive or negative charge

∙ Have gained or lost an electron

∙ Hydrogen Bonds

o Weak electrical attractions between polar molecules  (electrons not moving between molecules)

o Important to the properties of water

∙ Water’s Life Supporting Properties

o The polarity of water molecules and the hydrogen bonding  that results explain most of water’s life-supporting  

properties If you want to learn more check out Who are the achaeans in the odyssey?
Don't forget about the age old question of What is avoided cost method?

 Water molecules stick together (cohesion)

 Water has a strong resistance to change in  


 Frozen water floats

 Water is a common solvent for life sustaining  


∙ Does “Carbon-based” mean there’s more carbon than any other  element?

o No – Carbon forms the “skeleton” of molecules

o Carbon Skeletons

 Hydrocarbons (only C and H)

 All nonpolar (hydrophobic)

∙ CHNOPS (Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus,  Sulfur)

o Big elements

o More complex organic molecules

∙ Chemical Groups = “Functional Groups”

o Groups of atoms found in organic molecules

o Influence the water solubility of hydrocarbons

o Influence the function of the molecule

∙ Macromolecules

o Very large organic molecules

o Hundreds to million of atoms

o Common in cells

o Carbohydrates, nucleic acids, proteins, lipids

Lecture 2 (9/22/16) – Polymers and Monomers Don't forget about the age old question of How was the geography of the aegean different from that of mesopotamia and egypt?

∙ Polymer – Long chain of monomers

o Broken up by hydrolysis

 Chemical process of breaking down polymers

 Water added

 Process requires an enzyme  

∙ Dehydration Synthesis

o Builds polymers from monomers

o Chemical process

o Water removed

o Enzyme required

Link to dehydration synthesis chart can be found here ∙ Sugars take on ring form in water

o Glucose (an aldose)

o Fructose (a ketone)

∙ Glucose monomers link together with a covalent bond called a  glycosidic bond to for a disaccharide

o Maltose (glucose and glucose) – used to produce liquor,  malted items

o Sucrose (glucose and fructose) – table sugar

o Lactose (glucose and galactose) – sugar found in milk o Monosaccharides and disaccharides dissolve in water  easily – HYDROPHILIC

 Classified by location of carboxyl and number of  


∙ Polysaccharides

o Many sugars

 Linked together by dehydration synthesis

o Ex.

o Starch – Energy storage molecule for plants

 Plants store surplus starch as granules with  

chloroplasts and other plastids

o Glycogen – Energy storage molecule for animals

 Humans and other vertebrates store glycogen  

mainly in liver and muscle cells

o Cellulose – Structural polymer in plants

 Hydrophilic – Water sticks to the surface:  


 Different patterns of bonds in cellulose vs. starch  and glycogen

 Humans cannot digest cellulose (Beta Linkages):  lack enzyme to hydrolyze bonds

 Another name: “Dietary fiber” listed on nutrition  labels

 Many herbivores have symbiotic relationship with  microbes that can digest cellulose

o Chitin

 Also a polymer of glucose monomers

 Makes up insect and crustacean exoskeletons

∙ Lipids

o Fats and oils (triglycerides)

 Glycerol: “Head” region

 Fatty acid “tails”

 Triglycerides (fats vs. oils)

 Fat molecules contain much more energy than carb  molecules

 Saturated and unsaturated fats  

∙ Number of bonds in the hydrocarbon chain in a  

fatty acid

 Saturated Fats

∙ Generally bad for you  

∙ Animal fats (Lard, butter, shortening)

∙ Pack well – Solid at room temp. (Hll single  


 Unsaturated Fats (Fewer hydrogens)

∙ Generally good for you

∙ Plant fats and fish (olive oil, cod liver oil) high  

in unsaturated fats

∙ Liquid at room temperature (have one or more  

double bonds)

 Hydrogenation

∙ Adding hydrogens to unsaturated fatty acids

o Makes them saturated

 Fatty Acids

∙ Monomer f fat/oil/phospholipid molecules

∙ Unsaturated fatty acids can be cis or trans

o Phospholipids

 Major component of the cell membrane

∙ Membrane structure (bilayer)

∙ Separation of water-filled cells from watery  


o Steroids

 Cholesterol

∙ Important component of cell membranes

∙ Can attach to blood vessel walls and cause  

them to thicken

∙ Cell sin our liver produce almost 90% of  

circulating cholesterol

 Steroid hormones

∙ Estrogen

∙ Testosterone

o Waxes

 Strongly hydrophobic

 Protection

 Prevent dehydration

o All hydrophobic (non-polar)

o Store energy

Lecture 3 (9/27/16) - Proteins

∙ Many, many different proteins

o Each cell contains thousands of different proteins o Different types of cells produce different proteins ∙ Polymers of amino acids

o There are 20 amino acids

o Main structure

 Amino group

 Carboxyl group

 Central carbon

 Hydrogen atom

 R-group (side chain)

o Non-polar R-groups

 Decrease water solubility

 Hydrophobic

o Polar R-groups

 Increase water solubility

 Hydrophilic

∙ Amino Acids – Linked together by peptide bonds

o Polypeptides

 Polymer of polypeptides

∙ Structure (Proteins)

o A functional protein consists of one or more polypeptides  twisted, folded, and coiled into a unique shape

o Primary Structure

 Unique sequence of amino acids

o Secondary Structure

 Local patterns/structure held together by H-bonds  Coils (alpha helix) and folds (beta pleated sheets) o Tertiary Structure

 Overall 3-D structure of the protein held together by  chemical bonds between side chains (R-groups)

 H-bonds, ionic bonds, hydrophilic interactions

 Strong covalent bonds called disulfide bridges

o Quaternary Structure  

 Two of more polypeptide chains bonded together ∙ The ability of R-groups to interact with water and/or with each  other influences the formation of structure

o Non-polar R-groups internalize to minimize interaction with  water

 Polar and charged R-groups position themselves

∙ On the exterior where they will interact with  

water OR in positions to interact with each  


o Hemoglobin (alpha) (quaternary)

 4HHB

 Protein found in red blood cells that helps transport  oxygen through the body

o Hexokinase (alpha) (tertiary)

 1 CZA

 Enzyme that helps to break down glucose

o Glucagon (alpha) (secondary)

 Raises blood sugar if level gets too low

 Opposite effect from insulin

 Pancreatic hormone

o Transthyretin (beta and alpha) (quaternary)

o K+ (alpha) (qyaternary)  

 Channel (hole) in the middle


 Butterfly

 Donut

 Globular

 Long fiber

∙ Protein Structure

o Tertiary structure determines shape and function

o Binding pockets – To bind a target molecule

 Lactase – Protein that breaks down lactose (shape  

fits lactose)

Lecture 4 (9/29/16) – Denaturation, Biomolecules, Cell Theory ∙ Denaturation

o Loss of 3-D “native confirmation”

o Caused by excessive heating or salt, pH change

o Mutations can also change the shape of proteins

o Prions

 Proteinacious infections particles

o Consequences of flawed/misfolded proteins at cellular level  Generally reduced function

 Sometimes flawed proteins are destroyed

∙ Never get to final cellular destination

∙ Never perform intended function

 Sometimes flawed proteins form clusters in cell

∙ Whole or after inappropriate breakdown into  


∙ Interfere with normal cellular function

∙ Similarities b/w four classes of biomolecules

o Organic

o Contains one or more chemical groups

 Specific number, combination and arrangement of  

these groups characterize each type of molecule

o Fabrication of monomers (repeating subunits)

 Same chemical reaction (dehydration synthesis)

 Requires enzyme

 Degradation of monomers

o Degradation of monomers  

 Same chemical reaction (hydrolysis)

 Requires an enzyme

Biomolecular Class



Nucleic Acids




Amino Acids






Fatty Acids/Glycerol

Triglycerides/Phospholip ids

∙ Differences

o Interactions with water (hydrophilic/hydrophobic)

o DNA has phosphates

o DNA and proteins have Nitrogen, sugars and lipids don’t o Which atoms are present?

 Nucleic Acids: CHNOP

 Proteins: CHNO and a little S

 Carbohydrates: CHO in 1:2:1 ratio (in the monomer)  Lipids: CH and a little O (in phospholipids, only some  N and P)

o What chemical groups are present?

 Nucleic Acids: PO4 (charged), OH (polar) on  

backbone, various (polar) on bases

 Proteins: COOH (charged), N H2 (charged), variety  of R-groups ranging from polar to non-polar

 Carbohydrates: Lots of OH (polar)

 Lipids: Mostly hydrocarbon and C H3 (non-polar) o Which are hydrophilic/hydrophobic?

 All but lipids are hydrophobic

 What makes them this way?

∙ Their chemical groups

∙ Cell Theory

o What is a cell?

 All living things are made up of one or more cells  All cells came from pre-existing cells

 Cells are the basic unit of structure and function in  living things (basic unit of life)

o Least complex to most complex: Atom, molecule,  organelle, cell, tissue, organ, organ system, organism o Cells are the lowest level or biological organization that  exhibit all of the characteristics of life

∙ Characteristics of Life

o Organized

o Contain DNA

o Reproduce (like begets like)

o Grow and develop (controlled by DNA)

o Process energy

o Respond to environment

o Regulate internal conditions (homeostasis)

o Adapt

o Beneficial traits become more common in a population  over time

∙ Structures present in all cells

o Cell membrane  

 Outer limiting boundary

 Separates living cell from the non-living environment

o Cytoplasm

 Cytosol – Gel like fluid

 Internal structures


 Genetic instructions

 Heredity and cellular control functions

o Ribosomes

 Role in protein synthesis

o Based on their structure, we can categorize cells into two  


 Prokaryotes

∙ Domain bacteria

∙ Domain archea

∙ “Pro” = before, “karyon” = kernel/nucleus

 Eukaryotes

Lecture 5 (10/4/16) – Bacteria, Archea, Eukaryotes, Multicellular  Organisms

∙ Bacteria

o Hidden life

o Ex. E. coli

o Human Microbiome

 The body contains 10 times more bacteria, fungi, and

other micro-organisms than human cells

∙ Archea

o Can live in harsh environments

∙ Eukaryotes

o “eu” = true, “karyon” = kernel/nucleus

o 1 Domain, 4 kingdoms

 Protists

 Plants

 Fungus

 Animals

o Epithelial cells line our cavities and cover flat surfaces

o Fibroblast cells are found in connective tissue, they secrete

collagen and ECM

Differences between prokaryotic and eukaryotic cells



Smaller (1-10 μm)

Larger (10-100 μm)

No membrane bound internal components (organelles)

Many membrane bound internal compartments (organelles)

Small ribosomes

Large ribosomes


o Single circular molecule


o Linear molecule

o Not membrane enclosed

o “Nucleoid Region”

o Many (chromosomes)

o Look alike “pairs”

o Membrane enclosed

o Nucleus

∙ Why no huge cells? Surface Area vs. Volume ratio

∙ Plant vs. Animal Cells

o Animal Cells

 No cell wall

 Contain lysosomes and centrosomes

o Plant Cells

 Have cell walls

∙ Different than prokaryotic cell wall

 Few sperm cells have flagella

 Central vacuole – stores water, other chemicals

 Have chloroplasts

 Have plasmodesmata

∙ Multicellular Organisms

o Animals (humans too) and plants

 All eukaryotic

 Contain many different types of specialized  

(differentiated) cells

∙ Animals: Muscle, RBC, Keratinocyte, fibroblast

∙ Plants: Mesophyll, guard, epidermis

 All originated from the same single fertilized egg (aka


 Process by which these cells formed: Cellular  


∙ Cellular Differentiation

o Normal process by which immature undifferentiated cells  

develop distinct structures and functions of specialized  


o Underlying mechanism: Differential expression of genes in  the DNA

 Certain genes turned on (expressed)

 Others turned off (silenced)

o Result: Change in the number and type of proteins (the  

proteome) in the cell

 Defines morphology

 Defines specialized function

 >200 different kinds of specialized cells in human  

body, all begin with an undifferentiated cell (stem  


∙ Advantages of compartmentalization in eukaryotes

o Increased surface area

o Increased concentration of reactants used in chemical  reactions

 Higher concentration, higher rate

o Separation of incompatible reactions/reaction  


 Synthesis vs. degradation

 Reactions that need different environments

o Separation of products based on what they are for internal  or external use

 Internal

∙ Inside a membrane-enclosed organelle, e.g.  

enzyme in a lysosome

∙ Free-floating in the cytoplasm, e.g. enzyme  

needed for glycolysis (cytoplasm)

 External (export)

∙ E.g. collagen of ECM, insulin, digestive  

enzymes – e.g. trypsin – for use in intestines

∙ Ribosomes: Free and bound

o Free: In cytoplasm

 Translation of proteins used in cytoplasm

o Bound: Attached to RER

 Translation of membrane-associated proteins

∙ Proteins to be inserted into phospholipid  

bilayers of membranes

∙ Proteins for export from cell by exocytosis

∙ Proteins for membrane enclosed cellular  


Lecture 6 (10/6/16) – Cell Structures

∙ Lysosomes

o Round, membrane-enclosed, acid-filled vesicles that  function as garbage disposals

∙ Microfilaments (Actin filaments)

o Function = Cell shape; while cell movement (e.g. amoeboid movement)

o Easily disassembled and reassembled

o Function in cytokinesis

∙ Intermediate Filaments

o Generally not disassembled and reassembled

o Function = cell shape; reinforcement of cell junctions,  organelle placement, especially nucleus

∙ Microtubules – Tubulin Proteins

o Hollow tubes; can be disassembled and reassembled

o Functions: Arrangement of organelles; cell motility (e.g.  flagellum of sperm); intracellular transport (along with  accessory transport, e.g. kinesin)

∙ Membrane Functions

1. Barrier

 Cell membranes are gatekeepers

 Regulate what goes in and out

 Limiting boundary

2. Regulates Transport

 Passive transport (no energy required) is the  

spontaneous diffusion of molecules across a  


∙ Osmosis

o Passive diffusion of water across a  


o One of the most important substances to  

cross is water

o Body is 60% water

o There is water in and around cells

∙ Diffusion (high to low)

o Solutes – Particles being dissolved

o Solvents – Substance doing the dissolving

o Solution – Combination of solute and solvent

o Facilitated Diffusion – Most molecules can’t  

get through membranes on their own;  

carrier molecules – transport proteins

 Active transport – Requires ATP

∙ Molecules flow against their concentration  


∙ Needs energy

∙ Protein required

∙ Usually ions or small molecules

∙ Ex. Na+/K+ pump

 Bulk Transport

∙ Endocytosis and exocytosis

∙ Exocytosis – Transport of cell via vesicles that  

fuse with plasma membrane

∙ Endocytosis – Transport into cell via vesicles

o Phagocytosis – Engulfs large particles

o Pinocytosis – Cells taking in dissolved  

particles and liquid

o Receptor-Mediated – Bind to receptor  

proteins in the membrane

3. Communication

4. Recognition/Identification

5. Anchor

 Cell attachment via “junctions”

∙ Adjacent cells in many animal tissues are often  

directly connected by cell junctions consisting  

of specific proteins

o Tight Junctions – Keep things in the cell from


o Anchoring Junctions – Anchors to the cell;  

holds together

o Gap Junctions – Used to transport molecules

between cells

∙ Additional Cell Boundaries

o Cell wall made of cellulose

∙ Cell Membrane Structure

o Every cell is bordered by a plasma membrane

o Fatty acid tails hydrophobic because they are made of  carbon and hydrogen

o What’s there?

1. Phospholipids – Barrier that prevents the diffusion of  most material in and out of the cell

2. Proteins – Maintain cell shape; receptors; enzymes;  cell to cell recognition; intercellular junctions;  


3. Carbohydrates – CHO layer on external surface of cell (hooked onto lipids – glycolipids; hooked onto  

proteins – glycoproteins); recognition/identification’  

interaction with other ECM and other cells

4. Cholesterol – Stabilizes the membrane; keeps it  

flexible (not too flexible at warm temps.; not too rigid

at cold temps.)

Study Questions!!

Organic Molecules 

1. What is a molecule? What is the distinction between an organic  molecule and an inorganic molecule?

A molecule is a combination of atoms held together with covalent bonds; an organic molecule has carbon and hydrogen while an  inorganic molecule does not.

2. What is an atom? Draw the atomic structure of carbon, indicating the number and location of each proton, neutron, and electron. An atom is the smallest unit of matter that still retains the  properties of an element

3. What kinds of bonds does carbon  usually form with other atoms? How  many of these bonds does carbon  usually form?

Covalent bonds; four

4. What is a chemical (or “functional”) group? List 4-5 chemical  groups and describe how these chemical groups affect the water  solubility of the molecule to which they are attached. Groups of atoms found in organic molecules.

a. Hydroxyl Group – Hydrophilic

b. Carboxyl Group – Hydrophilic

c. Carbonyl Group – Hydrophilic

d. Amino Group – Hydrophilic

e. Phosphate Group – Hydrophilic

f. Methyl Group - Hydrophobic

5. What is the difference between a monomer (subunit) and a  polymer (macromolecule)? Provide examples on page 48 of your  text (question #2) to complete your review of this subject. A monomer is a molecule that can be bonded to other identical  molecules to form a polymer; a polymer is a long chain of  monomers.

6. How do your cells obtain monomers needed to make different  types of polymers that are essential to normal cell structure and  function?

They can break down other polymers using hydrolysis to get the  individual monomers

7. What is the chemical reaction that produces a polymer form  monomers? What does the name of the reaction tell you about  what is happening in the reaction? Diagram this reaction for any  one of the four classes of macromolecules.

Dehydration synthesis; a water molecule is being removed 8. What is the chemical reaction that produces monomers from  polymers? What des the name of this reaction tell you about  what is happening in the reaction? Diagram this reaction for any  one of the four classes of macromolecules.

Hydrolysis; a water molecule is being added

9. What is the significance of macromolecules to the human body? They are used in common body functions and are part of the  essential building blocks for cell function


1. What functions do proteins perform in your body? Give at least  four examples.

Catalyzing chemical reactions, protections, storage, transport,  responding to stimuli, support, and movement.

2. What is the basic structure of the repeating subunit (monomer)  for proteins? How many different types of this repeating subunit  exist, and what makes them different?

Amino group, carboxyl group, central carbon, hydrogen atom, R group (side chain); there are 64 different kinds, and they are  different because of their coding sequences

3. What is the overall structure of most functional proteins, that is,  their “native conformation” (functional shape)?

One or more polypeptides, twisted, folded, and coiled into a  unique shape; they are either shaped in alpha helixes or beta  pleated sheets.

4. What is the importance of this structure to the functioning of the  protein and, hence, the cell?

Shape determines function when it comes to proteins, so if the  protein is not shaped correctly, it will not function correctly, and  if it doesn’t function correctly, this will ultimately be detrimental  to the cell.

5. What ultimately determines the primary structure of all proteins? The sequence of amino acids

6. For the first three levels of protein structure, answer the  following questions:

a. What does this level of structure look like?

The primary structure is just the unique sequence of amino acids. The secondary structure the local pattern or  

structure held together by H-bonds. These look like either  alpha helixes or beta pleated sheets. The tertiary structure  illustrates the interactions between R-groups.  

b. What is the immediate determinant of this level of  structure (how did it get that way)?

In primary structure, it is the coding sequence. In  

secondary structure is the way the hydrogen bonds shape  it. In tertiary structure, it is the interactions between R groups.

c. What types of bonds stabilize (hold together) this level of  structure?

Primary – Peptide

Secondary – Hydrogen

Tertiary – Covalent bonds called disulfide bridges

d. What conditions can disrupt this level of structure? Primary – Mutations or wrong coding sequences

Secondary/Tertiary – Denaturation (excessive heating or  salt)

7. What does the fourth level of protein structure look like? What  types of bonds stabilize this level of structure, and what  conditions can disrupt it?

The Quaternary structure is two or more polypeptide chains  bonded together. The bonds can be van der Waals bonds,  hydrogen bonds, ionic bonds, or covalent bonds. Excessive heat  of salt can denature this structure.

8. Distinguish between globular and fibrous proteins.

Globular proteins are spherical (or rounded) and soluble in water  while fibrous proteins are not.

9. What is protein denaturation? Is the process reversible r  irreversible? If it can be either, under what conditions is it  reversible? Irreversible?

Denaturation is when a protein loses its 3-D native confirmation.  This process is reversible in very few cases in which the  denaturing agent is removed and protein goes back to its original shape.

10. Contrast protein denaturation with protein hydrolysis, in  terms of level of structure affected and reversibility.

Denaturation breaks down the quaternary structures whereas  hydrolysis breaks down the individual polymers in a protein.  Denaturation is very rarely something that is intentionally done,  therefore making it much more difficult to reverse, whereas  hydrolysis is organized and has a specific function and is  reversible more easily.

Carbohydrates and Lipids 

1. Why is CHO a good abbreviation for carbohydrates? Because all carbohydrates have these items

2. What are the monomer subunits for the carbohydrates? Monosaccharides

3. What is the structural difference between a monosaccharide, a  disaccharide, and a polysaccharide? How do they differ in  function?

A monosaccharide is one monomer, a disaccharide is two  monosaccharide monomers, and a polysaccharide is polymers of  hundreds to thousands of monosaccharides linked by  dehydration reactions. Monosaccharides and disaccharides are  linked together in glycosidic bonds and a hydrophilic.  

Polysaccharides are joined through dehydration synthesis and  are not all hydrophilic (only some are). There are used mostly as  energy storage.

4. What four different types of lipids exist? Where would you expect to find each one in the human body?

Fats and oils, phospholipids, steroids, and waxes. Fats (also  known as triglycerides) are in many places (mainly adipose  tissue) in the body and are mainly used for energy. Phospholipids are found mostly in cell membranes in the body. Steroids are also found partly in the cell membrane (cholesterol) but they can also be found where the hormones are located. Waxes are used for  protection and prevent dehydration. One of the main places they  can be found are the ears.

5. Identify the monomer subunit for triglycerides and  phospholipids.

Fatty acids/glycerol

6. Draw and label one phospholipid, in addition to labeling the  component parts – appropriately include the terms hydrophilic  and hydrophobic in your labels

7. Describe the unique structure of a steroid. A steroid has four rings of carbon  atoms with an attached hydrocarbon tail  and a hydroxyl group.

8. Distinguish the four different types of lipids based on their  function.

Fats and oils are used for energy. Phospholipids are used for cell  protection and regulation. Steroid are also used in membranes as signaling molecules. Waxes are used for protection and prevent  dehydration.

Cell Types and Basic Cell Structure 

1. What is a cell? What is the cell theory?

A cell is the basic unit of structure and function in living things  (basic unit of life). The cell theory says that all living things are  made up of one or more cells and that all cells come from pre existing cells.

2. What are the levels of biological organization?

Atom, molecule, organelle, cell, tissue, organ, organ system,  organism

3. What is the smallest/least complex level of biological  organization that exhibits all of the characteristics of life? Cells

4. What are the characteristics of life?

a. Organized

b. Contain DNA

c. Reproduce (like begets like)

d. Grow an develop (controlled by DNA)

e. Process energy

f. Respond to the environment

g. Regulate internal conditions (homeostasis)

h. Adapt

5. What four structures are present in all cells?

Cell membrane, cytoplasm, DNA, and ribosomes

6. What two major types of cells exist, and how do they differ? Give  some specific examples.

The two cells are prokaryotes and eukaryotes. Prokaryotes are  smaller than eukaryotic cells. They are 1-10 micrometers while  eukaryotic cells are 10-100 micrometers. There are no  membrane bound organelles in prokaryotes like there are in  eukaryotes. Prokaryotes have small ribosomes while eukaryotes  have large one. Lastly, their DNA characteristics differ in many  ways.

7. Which major cell type includes the cells in your body? Give some  examples of different cell types in your body. What distinguishes  these cells from one another?

We are made up of eukaryotic cells. A few different cells types  are epithelial cells and fibroblastic cells. These cells differ in  where they are found and the function they serve in the body.

8. Plants and animals (including humans) are multicellular  organisms. What characteristics do they share? If all of the cells  in a multicellular organism come from the same fertilized egg,  how do different types of cells form?

The characteristics that these cells share are that they are all  eukaryotic and contain many different types of specialized cells.  Even though these cells originated in the same place, they are  different because of a process call cellular differentiation.

Internal Cell Structure – Eukaryotic Organelle Structure and  Function 

1. Why does the inside of eukaryotic cells need to be subdivided  into compartments (organelles)? What separates these  compartments from one another? Identify 2-3 advantages of this  compartmentalization.

They are compartmentalized for organization purposes. These  compartments are separated by the cytoplasm as well as the  membranes that are around them. One of the advantages is that  there is an increased surface area. Another is the there is an  increased concentration of reactants used in chemical reactions.  Lastly, there is separation of incompatible reactions/reaction  environments so the cell can function properly.

2. What are the major intracellular structures of a eukaryotic cell  and how are they arranged?

a. Nucleus (and nucleolus) – Contains the DNA and  synthesizes RNA; spherically shaped with an envelope  around it and pores in it allowing for transport in and out

b. Ribosomes – Made of a large subunit and a small subunit;  broken down into two categories: free and bound; make  proteins and catalyze reactions

c. RER – Complex of folded material outside of nucleus  studded with ribosomes (hence, “rough”); produce protein  to be inserted into the membrane

d. SER – Similar to the RER, but with no ribosomes; used in  liver cells; synthesizes lipids; processes drugs, alcohol,  etc.; stores calcium ions

e. Golgi – Stacks sacks (membraneous); molecular  “warehouse”

f. Lysosome – Membraneous sac of digestive enzymes;  digestive organelle

g. Mitochondrion – Organelle composed of two membranes  and two internal compartments; used in cellular respiration and to produce energy (ATP)

h. Cytoskeleton – Made up of microfilaments (easily  disassembled and reassembled), intermediate filaments  (not disassembled and reassembled), microtubules (can be disassembled and reassembled)

3. What do the individual structures do for the cell (their function)?  Use the “cell structure self-quiz” on Blackboard.

See #2

4. Do these structural parts of the cell work separately or together  or both? If together, describe at least one example, listing the  structure and function of the cytoskeleton. Distinguish between  microfilaments, intermediate filaments, and microtubules. They work together. They all work to support and shape the cell.  Microfilaments contribute to the cell’s shape and movement.  Intermediate filaments contribute to cell shape and reinforce cell  junctions and organelle placement. Microtubules arrange the  organelles and work in the motility of the cell. They also work  with intracellular transport.

5. Identify and distinguish between three types of cell junctions that allow adjacent cells to interact.

Tight junctions keep things in the cell from the body. Anchoring  junctions anchor to the cell and hold it together. Gap junctions  are used to transport molecules between cells.

6. What is the difference between a plasma membrane and a cell  wall?

A cell wall is made of cellulose and is much more rigid than a  plasma membrane.  

Cell Membrane Structure and Function 

1. What is the structure of the plasma membrane of the cell? What  molecules are present in this membrane? Draw a diagram of a  segment of the membrane, and label each type of molecule. Membrane made of phospholipids with polar heads and non-polar tails.

2. How can a signaling molecule from one cell alter gene expression in a target cell without even entering the target cell?

There are intercellular communications.

3. What are the major functions of this outer membrane? Barrier, regulating transport, communication,  

recognition/identification, anchor

4. What are the major types or membrane transport, i.e. ways by  which material gets into and out of cells? How are they similar?  How do they differ? Provide an example of a material that might  be transported by each type of membrane transport.

Passive transport, active transport, and bulk transport. Passive  transport uses no energy while active and bulk both do. Passive  transport doesn’t always require a protein (though sometimes it  does) while active and bulk always require one. One of the most  common examples of passive is osmosis, the diffusion of water  across the membrane. A good example of active transport would  be the sodium potassium pump. And bulk transport would be  large molecules that can’t even go through the active transport  proteins.

5. What is osmosis? What is the relationship between osmosis and  diffusion?

Osmosis is the diffusion of water across the membrane. So  osmosis is a kind of diffusion (diffusion is just the passive  transport of molecules either by protein channels ore just  through the membrane itself.

6. How does a cell move material in bulk (large quantities) across  the plasma membrane?

The cells use two different kinds of transport: exocytosis (out of  the cell) and endocytosis (into the cell). Also in endocytosis are  subcategories: phagocytosis (engulfing large particles),  pinocytosis (taking in liquid/dissolved particles), and receptor mediated (binding to receptors proteins on the membrane.

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