EXAM 1 CBIO 2200 STUDY GUIDE
1. Why study Anatomy and Physiology?
- We must understand normal structure and function so you’re able to identify abnormal or incorrect function
-We must understand mechanisms of therapies used to treat dysfunction -Identify targets for new therapies
-If you understand what is wrong with the patient, you can compose a mechanism to treat them
We are trying to understand “How does the human body work?” 2. Pathophysiology vs. Physiology
Pathophysiology: functional changes associated with disease and aging
Anatomy: the branch of biology concerned with the study of the structure of organisms and their parts.
Physiology: The branch of biology that deals with the study of organ function and interaction. OR The branch of biology that deals with the normal functions of living organisms and their parts.
3. Levels of organization of the human body:
e) Organ system
Necessary life functions of humans:
-Movement (both walking and the movement of substances in the internal environment)
-Respond to stimuli in the environment
a) The “overall job” of every system in the body
b) Balance! If you want to learn more check out what is Internet Protocol?
“Condition of equilibrium (balance) in the body’s internal environment..” Interplay of many, many processes
Maintain certain, particular internal conditions
-Internal chemical reactions operate at specific pHs (certain enzymes work best in certain pHs. Proteins can become denatured at the wrong temperatures) Why did we watch a video about Helen Keller? Helen Keller had scarlet fever and was sick for more than a week, losing her sight and hearing. Because the temp was disrupted and she therefore lost sight and hearing, it’s interesting to see the correlation.
5. Feedback and feedback systems
a) Maintain homeostasis
In a negative feedback loop, a stimulus- a deviation from a set point- is resisted through a physiological process that returns the body to homeostasis -A negative feedback loop has four basic parts If you want to learn more check out What is the goal of integrated marketing communications?
-Body temperature is regulated by negative feedback
stimulus, receptor, control center, and effector (four parts)
The effector brings about a change that restores the homeostasis
The response “feeds back” to affect the stimulus (hence, “feedback”)
BODY TEMPERATURE IS REGULATED BY NEGATIVE FEEDBACK Temperature Rises (stimulus)
Control Center (also thermostat) Don't forget about the age old question of What is Amplitude?
Effector (AC unit)
Response (Temperature falls)
Negative feedback because the temperature is increasing, but the response is a decrease in temperature. The stimulus and response are in opposite directions. The response negates the effect of the stimulus.
A positive feedback loop is when the stimulus is reinforced by the response- less common in physiology because then net result is that the response pushes you further away from that set point. Positive feedback loops are more likely to become life threatening. (like blood clots)
NEGATIVE FEEDBACK tends to negate the effect of the stimulus (blood pressure, blood sugar, body temperature)
POSITIVE FEEDBACK tends to reinforce the effect of the stimulus Don't forget about the age old question of What is in the reticular region of the dermis?
(understand that blood clotting is an example of a negative feedback loop) as your blood clots, it continues to clot more and more.
Positive feedback involves amplification and the output enhances the original stimulus. i.e. blood loss leads to decrease in blood pressure which causes more blood loss. Blood loss also causes blood clotting, which causes more blood clotting.Don't forget about the age old question of What is the major benefit of written vs oral communication?
We also discuss several other topics like There have been how many amendments to the U.S. Constitution?
A classic example of positive feedback loop is childbirth:
A positive feedback loop results in a change in the body’s status -The receptors would be the stretch receptors in the cervix
-The control center is the posterior pituitary of the brain
-The effectors are the uterine wall muscles contracting/the oxytocin that causes them to do so
1. Elements, Atoms, Ions and Isotopes: Review of some basic terms and definitions
c) Atomic number (Z)
-Number of protons
-Defines the element
d) Atomic Mass (mass number)
-Can differ based on number of neutrons
-The average atomic mass (calculated from isotopes) is on the periodic table
e) What happens when there are different numbers of electrons between atoms of the same element? (Cations-positively charged and Anions negatively charged)
f) What happens when there are different numbers of neutrons between atoms of the same element? (Isotopes)
2. Chemical Bonds
a) The octet rule- atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.
b) Ionic bonds- transfer of valence electrons between atoms and generally results in two oppositely charged ions.
c) Covalent bonds (sharing electrons between atoms, within a molecule) d) Polar vs. Non-polar covalent bonds
Non-polar- equal sharing of electrons- no net dipole moment
Water molecules have unequal sharing of electrons (polar-covalent) bonds. Therefore, it’s partially attracted to other water molecules. It’s
an excellent polar solvent.
e) Hydrogen bonds
i. Really, these are a special case of covalent bonds
ii. These are attractions BETWEEN molecules, rather than bonds that hold atoms together within molecules
iii. BUT they are also important WITHIN large molecules in holding them in a particular shape
3. Chemical reactions
a) Synthesis (anabolism)
A + B ???? AB
b) Decomposition (catabolism)
Taking something apart
AB ???? A + B
Reactants ???? Products
AB + CD ???? AC + BD
Reactants ???? Products
AB ???????? A + B
Forward reaction: left to right
Reverse reaction: right to left
To make reactions happen faster you can: increase temperature, have more reactants to react with each other, or lower activation energy.
i. Often are enzymes in biological systems
-Enzymes decrease the activation energy required for a given chemical reaction to occur (brings reactants closer together) -Most often, enzymes are proteins
-Without an enzyme, the energy input needed for a reaction to begin is high.
-With the help of an enzyme, less energy is needed for a reaction to begin.
Temperature and pH can affect enzyme efficiency
4. Properties of water, acids, bases, and salts
a) Water is critically important in living systems
b) Water is an excellent solvent
c) Water dissolves polar substances
Water can surround elements and cause them to separate from their ionic bonds Ionic compounds (held together with ionic bonds) dissociate into ions in water NaCl(aq) ???????? Na+(aq) + Cl-(aq)
(reassociation is possible too!)
Electricity is like movement of ions in the body- Sodium is key. Dissociation Reactions:
KI(aq) ???????? K+ + I
CaCl2(aq) ???????? Ca2+ + 2Cl
Na2So4(aq) ???????? 2Na+ + (So4)^2-
Salts and acids dissociate into ions:
CaCl2(aq) ???????? Ca2+ + 2Cl
HCl(aq) ???????? H+ + Cl
Acids dissociate into hydrogen ions
Bases dissociate into [hydroxide] ions:
Acids can donate protons, or accept electrons
Bases can accept protons, or donate electrons
Acids and bases combine to form salt and water:
Hydrogen ions combine with hydroxide ions to form water:
Water dissociates into hydrogen ions and hydroxide ions:
Only a little dissociates.
• Higher concentrations of H+
• Greater than 1x10^-7 M of H+
• Lower concentrations of OH
• Lower concentrations of H+
• Lower than 1x10^-7 M of H+
• Higher concentrations of OH
Compounds that dissociate into ions in water are ELECTROLYTES
**Acids and bases dissociate into ions
**Hydroxide ions and hydrogen ions combine to form water
5. Hydrogen ion concentration and pH
As H+ concentration increases, the pH goes down
As the H+ concentration decreases, the pH goes up
a) Water dissociates into hydrogen ions and hydroxide ions b) Normal concentrations of H+ and OH- are equal in water
c) Acidic solutions have more H+ than normal water
d) Basic solutions have less H+ (and more OH-) than normal water e) pH is a way to express the concentration of H+ in a solution i) pH = -log[H+]
pH of the body is 7.4
Which is more acidic (lower number on pH scale); a solution with pH = 9.82 or a solution with a pH= 9.65? The pH of 9.65
Which has a higher concentration of H+? pH of 9.65
When the body becomes more acidic, does the pH increase or decrease? Decrease
How can stomach acid have a pH that is outside the range of pH compatible with life and still be part of the living body?
-It has a specialized lining
Sodium bicarbonate in alka seltzer is a base, which neutralizes the acid in heartburn
Sphincter allows acid to splash into esophagus, which burns
Another brand uses calcium carbonate, which neutralizes the acid too An acid and a base neutralizing each other is called an exchange reaction to make a salt and water. (Exchange reactions can be reversible. What distinguishes them is that there’s an exchange of one or more ionic components) (The products of an exchange reaction are neutral and stable)
a) Resist changes in pH
b) Important in maintaining the internal pH at a constant level c) Act by “tying up” excess H+ and OH-, preventing them from changing the pH
d) Combine with both H+ and OH
e) Buffers are mixtures of weak acids or bases and their corresponding salt
Weak acids- less dissociation into ions than strong acids
H2CO3 ???????? HCO3- + H+
Doesn’t dissociate completely^^ but very little of the parent compound itself is left.
Strong acids and bases are more likely to completely dissociate into OH- and H+ H+ can then combine with OH- and form H2O
Provides a “handle for OH-“
So what could tie up the excess H+ ions in our weak acid example? HCO3- + H+ ???????? H2CO3-
Provides a “handle” for H+
Therefore, resists a change in pH
If we mix a strong acid and a weak base, the weak base will react with the H+ from the strong acid, forming a weak acid and buffering.
If we mix a strong base with a weak acid, the weak acid will donate its H+ to the strong base’s OH- to form water, buffering the system.
7. Introduction to Organic Chemistry and Functional Groups
(See table 2.1 in OpenStax; table 2.5, p.42 in Tortora)
a) Organic Chemistry is the chemistry of C-containing compounds b) Functional groups give the molecule different properties
i. Monosaccharides, disaccharides, and polysaccharides
We use carbohydrates for energy: sugars, starch
Dehydration synthesis means you’re losing a molecule of water
Individual molecules are synthesizing larger molecules.
Glycogen is a starch, stored in your liver as a potential fuel source.
When glycogen is broken down, we start at the ends of the molecule (9 ends). If its more branched, you have more places to hydrolyze and it’s faster to break it into single strands and then break it down further.
What do carbohydrates do in the body?
• Provide energy
• Act as signal molecules
• Contribute to structure and function of DNA and RNA
d) Lipids and phospholipids
If a fatty acid is saturated, all of the bonds are going to be taken up by hydrogen. Every bond is a single bond. In palmitic acid, there is a long chain, and it’s
saturated. You can have up to 3 fatty acids stuck to the glycerol backbone.
Mono, di, and tri glycerides
The fatty acids do not have to be the same.
Mono unsaturated means that there is one double bond.
All of the carbons have to be saturated to make the molecule as a whole
“saturated. Therefore, the example above is unsaturated.
Phospholipid: phosphate group and 2 fatty acid tails- one region can interact with water (the polar head) and one region cannot (the nonpolar tail). There is also a
glycerol backbone. Polar and non-polar ends. The phosphate group is important for the polarity of the head.
This is called an AMPHIPATHIC molecule^^
All of these molecules have 4 rings. Help maintain the fluidity of the cell, but also maintains its firmness so the cell membrane doesn’t turn to mush. They’re lipid soluble. The body needs cholesterol, because it uses it. Cholesterol has a small, water-soluble polar region that dissolves in water (the OH), but nearly the entire cholesterol molecule is non-polar, which will NOT dissolve in water — like oil. This makes cholesterol an example of an amphipathic molecule — part water soluble, part water-insoluble.
Amino acids together are called peptides and held together by peptide bonds. Peptide bonds are covalent bonds.
Monosaccarides forming disaccharides, fatty acids combining with glycerol, and joining amino acids to make a peptide, are all examples of dehydration synthesis.
There are 6 amino acids in this structure, and 5 peptide bonds. They only fit together in a chain. This is the primary structure (amino acid sequence)
Amino acids have peptide bonds and hydrogen bonds (that form the secondary structure)
The above picture depicts two types of secondary structures. Hydrogen bonds are keeping the shapes of the secondary structures. In a beta-pleated sheet, the molecule is folded. In the alpha helix, the R groups are on the outside. In the beta pleated sheet, the H bonds are between strands. The strands can either be parallel or anti parallel. B sheets are more stable than Alpha helixes.
Collagen- maintains tough structure in skin.
Tertiary structure- involves the overall folding and shape of the protein. The protein molecule will bend and twist in such a way as to achieve maximum stability or lowest energy state
Quaternary structure- number and arrangement of multiple folded protein subunits in a multi-subunit complex. The quaternary structure refers to how these protein subunits interact with each other and arrange themselves to form a larger aggregate protein complex.
Hemaglobin- transports oxygen. One hemoglobin carries 4 molecules of oxygen
f) Nucleic Acids- DNA and RNA
Nucleic acids are composed of nitrogen containing bases, 5 carbon sugars, and phosphate groups in a ladder-like arrangement.
a) ATP- ribose sugar, an adenine base, and three phosphate groups. ATP is classified as a high-energy compound because the two covalent bonds linking its three phosphates store a significant amount of potential energy. In the body, the energy released from these high energy bonds helps fuel the body’s activities, from muscle contraction to the transport of substances in and out of cells to anabolic chemical reactions. Can donate the phosphate group to other molecules (phosphorylation). Important signaling pathways inside cells.
Monomers for carbohydrates: monosaccarides
Monomers for lipids: fatty acid chains and glycerol
Monomers for proteins: amino acids
Chart/table of organelles and their functions. We should be prepared to identify an organelle and describe its function.
1. Generalized Cell Structure
The nucleus tells you that you’re looking at a cell and clues you in to the type of cell and they type of tissue.
a) 3 general areas to be studied more in detail
• Plasma Membrane
• Cytoplasm and associated organelles
2. Plasma Membrane
a) Lipids (mostly phospholipids) (blue and pink) (polar heads are blue and fatty acid tails are pink) (bilayer)
• The polar heads come into contact with the watery extracellular environment and the watery cytosol
• The non-polar fatty-acid tails are in contact with each other. Hydrophobic environment. This fatty layer makes the plasma membrane such a good barrier.
• The proteins sit in and span the plasma membrane. One side on inside, and one side on outside.
• The purple strings are structural proteins that also span the membrane and interact with other proteins
• The purple strings are carbohydrate molecules, either
associated with the lipids or the proteins
• The tiny orange strings near the hydrophobic tails are
cholesterol and contribute to the fluidity
“A sea of phospholipids”
Function of lipids
• Form barrier, form the structure or skeleton (framework) of the membrane. The amphipathic property is very important
Functions of membrane proteins
• Transport substances across the lipid bilayer
• Enzymes (proteins are enzymes)
• Receptors for some stimulus
• Join membranes to adjacent cells
• Cell identity markers (needs to identify, or immune system will attack)
If plasma membranes are barriers, how do things get in/out of the cell? • Several ways, depending on the type of substance crossing • Active (requiring energy)
• Passive (no energy required)
3. Transport of substances across membranes
a) Passive processes (Do NOT require energy input by the cell) Substances move across a membrane
Substances move from an area of higher concentration to an area of lower concentration (down the concentration gradient)
Kinetic energy is the energy of movement
• The movement of molecules or ions form a region of higher concentration to a region of lower concentration
• Depends on the kinetic energy of the molecule or ion (i.e.
heating up the system so they diffuse faster)
• Substances diffuse down their concentration gradients i) Simple diffusion- a polar molecule isn’t likely to diffuse through. Have to be really really small and non-polar (hydrophobic) (CO2 and O2) Water has to use a channel because it has to be regulated.
ii) Facilitated diffusion- anything that has to use a channel to get across, but no ATP is facilitated diffusion. “The spontaneous passive transport of molecules or ions across a membrane via specific transmembrane integral proteins.”
When the molecule interacts with the channel, the channel changes shape and is let through)
(An ion channel is a different entity, and we will talk about it later)
iii) Osmosis (special case of diffusion)
“Water moves form an area of lower solute concentration to an area of higher solute concentration”
“Moving from where there’s more water to where there’s less water”
The membrane is permeable to water but not to the solute. The water will move until the hydrostatic pressure (pressure exerted by a fluid against a container, vessel) opposes it. • Movement of H2O across a membrane
• Describing the differences in solution concentrations across a permeable membrane
a) Isotonic- surrounding medium has the SAME
concentration of solute as cell interior
b) Hypertonic- Surrounding medium has MORE solute than cell interior
c) Hypotonic- Surrounding medium has LESS solute than the cell interior
If we take a cell and put it in a hypotonic solution, the cell
will swell and burst
If we put a cell into a hypertonic solution, the cell will
shrink (water moving from cell to environment
“The flow of liquid through a filter (or membrane that acts like a filter) due to hydrostatic pressure
Pushing of fluid through a membrane
• Due to pressure of the fluid
b) Active processes
• Require some sort of energy
• Energy provided by ATP OR the energy is provided
indirectly by another process
i) Primary active transport
• Hydrolysis of ATP provides energy to “drive” the
• Usually catalyzed by membrane protein “pumps”
• Can result in the formation of a concentration gradient
across a membrane
• Na+/K+ ATPase or Na+/K+ pump is an example
• Not limited to moving substances down a concentration gradient (very often moving against- from where there’s
less to where there’s more)