Midterm 1 Practice

Question 1

Enzymes can help lower the activation energy barrier by

Answer 1

Trapping/orienting substrates
Providing reactive groups

Question 2

3 key ideas about cytoskeleton fibers

Answer 2

Composed of monomers
Not symmetrical
Dynamic

Question 3

What part of the amino acid holds the secondary structure together with H-bonds?

Answer 3

The backbone of carboxylic acid and amino groups form the H-bonds that hold the secondary structure together

Question 4

What is the membrane interface?

Answer 4

The region between the fully aqueous environment outside the membrane and the hydrophobic core within the bilayer

Question 5

In a mix of aqueous components and a phospholipid bilayer, where will charged particles go?

Answer 5

Towards the membrane interface, since they can interact with the phospholipids’ polar heads

Question 6

Do enzymes affect equilibrium concentrations and why?

Answer 6

They don’t because they only affect activation energy, not final and starting Gibbs free energy which would impact final concentrations

Question 7

What is the difference between primary and secondary active transport?

Answer 7

Primary active transport: Uses ATP as an energy source to move ions/molecules against their concentration gradient

Secondary active transport: Relies on an electrochemical gradient for energy, coupling the movement of one substance down its gradient with another against its gradient