EXAM1_L11_Enzyme_Kinetics

Question 1

Michaelis & Mentin

Answer 1

1913

Question 2

Kcat- turnover number

Answer 2

Vmax/[E]total; represents efficiency of enzyme;

product per second per enzyme molecule

Question 3

if V»»km or if V

Answer 3

V»>km rate is zero order

V

Question 4

Hexokinase vs Glucokinase

Answer 4

Hexokinase High km for glucose (only works at high glucose concentrations after meals). prevents hyperglycemia
Glucokinase low km for glucose and works to supply glucose to brain constantly

Question 5

Lineweaver burke plot. x axis y axis slope

Answer 5

Xaxis intercept= -1/km
Yaxis intercept= 1/Vmax
Slope = km/vmax

Question 6

B-lactam antibiotics (penicillin/amoxicillin)

Viagra, Ibuprofen (motrin/advil), acetaminophen (tylenol)

Answer 6

Enzyme inhibitors

Question 7

Statins (atorvastatin-lipitor; simvastatin-zocor) are ____inhibitors of __________ . The enzyme that catalyzes the rate-limiting step in _____.

Answer 7

competitive inhibitors of HMG CoA reductase of Cholesterol biosynthesis

Question 8

Statin structure- function

Answer 8

structural analogs of HMG CoA- competitive inhibition

Reduces cholesterol synthesis and lower plasma cholesterol

Question 9

Suicide substrates; examples

Answer 9

unreactive until bind active site- inert form ingested- modified by the enzyme-irreversible binding.
-effective drugs/few side effects
penicillin- aspirin (acetyl salicylate)-ser residue
Disulfiram(antabuse)- aldehyde dehydrogenase (accumulate acetaldehyde)