Question

1) You have a molecule that you want to move from outside the cell to inside the cell via passive diffusion. Assuming your concentration gradients are appropriate, which molecule is most likely to move in this way?

Triglyceride

Serine

dATP

K+

Glycerophospholipid

2) You evolve an antibiotic-making enzyme in a lab that has different kinetic properties than the version found in nature. You are hoping to one day sell this improved enzyme to companies that make antibiotics. Which of the following kinetic parameters do you hope are now HIGHER (ie larger values)?

kcat and Km

kcat, Km, and kcat/Km

Km and kat/Km

kcat and kcat/Km

Answer 1

Ans1)triglyceride

Explaination:triglyceride are lipophilic molecule which passes through plasma membrane by simple diffusion that is a passive diffusion.

Ans2)kcat and kcat/km

Explaination:

Kcat is turn over number of enzyme ie, number of substrate converted to product by an enzyme in unit time.So high the Kcat of an enzyme more substrate will be converted to product.

Kcat/km is specific constant which measures the enzyme efficiency. So more the kcat/km ratio more will be enzyme efficiency.

Km measures the affinity of enzyme for substrate. More the Km less will be affinity or vice versa hence lower value of km is better for a better enzyme efficiency

So antibiotic making enzyme will have high kcat and kcat/km .