Section 1

Question 1

pH of arterial plasma

Answer 1

7.35-7.45

Question 2

pH of extracellular fluid

Answer 2

6.8-7.8

Question 3

pH within cells

Answer 3

6.9-7.4

Question 4

If pH<pKa, then what form predominates?

Answer 4

acid

Question 5

If pH>pKa, then what form predominates?

Answer 5

basic

Question 6

what is the buffer system of blood?

Answer 6

bicarbonate

Question 7

What is the intracellular buffer system?

Answer 7

phosphate

Question 8

What is this condition?

increase in partial pressure of CO2

Answer 8

resipratory acidosis

Question 9

What is this condition?

decrease in partial pressure of CO2

Answer 9

respiratory alkalosis

Question 10

What is this condition?

decrease in HCO3- concentration

Answer 10

metabolic acidosis

Question 11

What is this condition?

increase in HCO3- concentration

Answer 11

metabolic alkalosis

Question 12

What condition is due to decrease in lung function and how will the body do to compensate?

Answer 12

Respiratory Acidosis

• kidneys will try to compensate by increasing bicarbonate
• all compensatory reaction by the kidneys will take several days

Question 13

What condition is due to hyperventilation and what will the body do to compensate?

Answer 13

Respiratory Alkalosis

- kidneys will try to compensate by excreting bicarbonate in urine

Question 14

What condition can be caused by decreased kidney function or body trying to compensate for an already existing acidosis, such as DKA? How will the body try to compensate?

Answer 14

Metabolic Acidosis

• lungs will attempt to compensate by “blowing off” CO2
• this effect will take place within minutes and complete within 12 - 24 hours

Question 15

What condition can be caused by an excess administration of bicarbonate or loss of H+ (from prolonged vomiting or use of diurectics)? How will the body compensate?

Answer 15

Metabolic Alkalosis

- lungs will attempt to compensate by breathing less (hypoventilation), trying to keep as much CO2 as possible

Question 16

What type of protein structure is this?

structure results from hydrogen bonding interactions between C=O and H-N of the backbone

Answer 16

Secondary structure

Question 17

What type of protein structure is this?

subunits associate with each other through non-covalent interactions?

Answer 17

quaternary

Question 18

What type of protein structure is this?
sequence of amino acid residues in a polypeptide chaing
- determines 3-D structure and biological function of the protein

Answer 18

primary

Question 19

What type of protein structure is this?
non-covalent interactions are the major element in formation of this structure (H-bonding, hydrophobic forces and van der Waal’s)

Answer 19

tertiary

Question 20

What type of enzyme is this?

catalyzes cleavage of bonds with water

Answer 20

hydrolases

Ex. glucosidases, ATPases

Question 21

What type of enzyme is this?

catalyzes redox reactions, transfer of electrons

Answer 21

oxidoreductase

Ex. NAD+»NADH

Question 22

What type of enzyme is this?

catalyzes transfer of functional groups

Answer 22

transferases

Ex. kinases, aminotransferases

Question 23

What type of enzyme is this?

catalyzes formation of bonds between carbons and other atoms

Answer 23

ligases

Ex. synthase, synthetase, carboxylase

Question 24

What type of enzyme is this?

cleaves bonds without water

Answer 24

lyases

Ex. aldose B

Question 25

What type of enzyme is this? | changes stereochemistry

Answer 25

isomerase

Question 26

Holoenzyme

Answer 26

apoenzyme with prosthetic group | - active

Question 27

Apoenzyme

Answer 27

apoenzyme without its prosthetic group | - inactive

Question 28

Vmax, conditions

Answer 28

more substrate will not increase reaction rate, but more enzymes will - does not depend of concentration of subtrate

Question 29

Km, conditions

Answer 29

- more enzymes will not change this value

Question 30

What does a low Km mean?

Answer 30

increase substrate affinity - takes more substrate to be at Vmax/2 this explains why glucokinase can turn over more G6P from glucose than hexokinase

Question 31

What does a high Km mean?

Answer 31

decrease substrate affinity | - takes only small amount of substrate to be at Vmax/2

Question 32

Conditions of competitive inhibition

Answer 32

``` Vmax - no change because it's independent of substrate concentration Km increases (substrate concentration dependent) - less substrates are binding ```

Question 33

Conditions of non-competitive inhibition

Answer 33

``` Vmax decreases (number of enzymes changed due to the inhibition) Km - no change - fewer working enzymes ```

Question 34

Gs G-proteins

Answer 34

stimulates adenylate cyclase to form cAMP

Question 35

Gi G-proteins

Answer 35

inhibits adenylate cyclase

Question 36

Gq G-proteins

Answer 36

stimulates phospholipase C to form IP3/DAG

Question 37

Which is better at binding to oxygen during low levels of O2, myoglobin or hemoglobin?

Answer 37

myoglobin

Question 38

What is better at binding to oxygen during high levels of O2, myoglobin or hemoglobin?

Answer 38

hemoglobin

Question 39

Which form of Hb has a higher affinity for O2, T or R?

Answer 39

R form

Question 40

What kind of allosteric modulator is O2 on Hb? What about 2,3-BPG, CO2 and H+?

Answer 40

O2 is a positive allosteric modulator of Hb, all the others are negative allosteric modulators of Hb

Question 41

CO2 can bind to N-terminal ends of Hb subunits and form carbamates, what effect will this have on the structure of Hb?

Answer 41

stabilizes T-form, facilitate release of O2 in peripheral tissues