Exam 3 Key Points

Question 1

binding of _______ is an important function of many proteins

Answer 1

ligands

Question 2

What does Kd measure?

Answer 2

the affinity of a protein for its ligand

Question 3

What is Kd?

Answer 3

the ligand concentration at half-maximal binding

Question 4

What is Scatchard analysis used for?

Answer 4

measure Kd and number of binding sites (Bmax)

Question 5

What are the 2 types of receptors?

Answer 5

cell surface and intracellular

Question 6

How does desensitization occur?

Answer 6

prolonged exposure

Question 7

What is cholesterol synthesized from and how?

Answer 7

Acetyl-CoA through HMG-CoA mevalonate and isoprene intermediates
under hormonal control
regulated by HMG-CoA reductase

Question 8

What is cholesterol a precursor for?

Answer 8

steroids and bile acids

Question 9

What are statins inhibitors of?

Answer 9

HMG-CoA reductase

Question 10

explain Anaerobic Glucose metabolism

Answer 10

-low energy yield
-very rapid

Question 11

explain aerobic glucose metabolism

Answer 11

-much more energy
-slower
- limited by oxygen

Question 12

What are the two types of muscle fibers?

Answer 12

Type I (dark) mostly aerobic
Type II (light) mostly anaerobic

Question 13

Are tumors aerobic or anaerobic?

Answer 13

Anaerobic, they have a high rate of glucose uptake and can be detected by PET scanning

Question 14

Where are dietary proteins digested?

Answer 14

stomach and intestine

Question 15

What are amino acids taken up by?

Answer 15

Specific amino acid transporters

Question 16

How is the amino group removed of the amino acid?

Answer 16

-transferred to alpha-ketoglutarate to form glutamate (transamination)
-removed as NH4+ (oxidative deamination)

Question 17

How is ammonia formed in other tissues transported?

Answer 17

glutamine of from muscle alanine

Question 18

How is ammonia converted in mammals?

Answer 18

Ammonia is converted to urea in the urea cycle (liver) and excreted via the kidneys

Question 19

What can the carbon skeleton (keto acid) be?

Answer 19

ketogenic or glucogenic or both, can be metabolized to acetyl-CoA, acetoacetyl-CoA, or various Krebs cycle intermediates

Question 20

Which type of regulation is more common, positive or negative?

Answer 20

positive

Question 21

What do promotes for Pol II have?

Answer 21

TATA box and multiple binding sites for transcription activators

Question 22

What are the two ways that hormones regulate transcription?

Answer 22

-steroid hormone receptors bind directly to DNA
-other hormones bind to cell-surface receptors and trigger signaling pathways that phosphorylated regulatory proteins

Question 23

How are catabolic and anabolic pathways regulated? general

Answer 23

to match energy needs to nutrient supply

Question 24

How is short term regulation mediates?

Answer 24

allosteric regulators and covalent modification

Question 25

How are long term changes mediated?

Answer 25

changes in gene expression