Question 1

Which type of enzyme inhibition involves the inhibitor binding only to the enzyme-substrate (ES) complex, forming an ESI complex?

Accepted Answer

uncompetitive

Question 2

Given the Lineweaver-Burk plot below, which shows a family of lines with parallel slopes as inhibitor concentration increases, what type of inhibition is most likely present?

Accepted Answer

uncompetitive

Question 3

The $K_m$ value for the substrate in the enzyme assay shown is determined by the x-intercept of the Lineweaver-Burk plot. If the x-intercept is $-1/0.25$ $\mu$M$^{-1}$, what is the $K_m$?

Accepted Answer

$0.25\ \mu$M

Question 4

In the absence of inhibitor, the $V_{max}$ value for the enzyme-substrate system used in the above assay is given by the y-intercept of the Lineweaver-Burk plot. If the y-intercept is $1/40$ min/$\mu$M, what is $V_{max}$?

Accepted Answer

$40\ \mu$M/min

Question 5

Estimate the $K_i$ of the inhibitor if the $K_m$ increases from $0.25\ \mu$M to $1\ \mu$M in the presence of $2\ \mu$M inhibitor. Use the equation $K_m^{app} = K_m (1 + [I]/K_i)$. What is $K_i$?

Accepted Answer

$2\ \mu$M

Question 6

The Michaelis-Menten equation $v_0 = \frac{V_{max}[S]}{K_m + [S]}$ describes the relationship between:

Accepted Answer

enzyme activity as a function of substrate concentration

Question 7

The $K_m$ is:

Accepted Answer

equal to the substrate concentration when the reaction rate is half its maximal value

Question 8

When $[S] \ll K_m$, the enzymatic velocity depends on:

Accepted Answer

the values of $K_{cat}$, $K_m$, and $[E]$

Question 9

A patient accidentally ingests methanol. A physician administers ethanol, which competes for alcohol dehydrogenase and prevents methanol toxicity. This is an example of:

Accepted Answer

competitive inhibition

Question 10

Which of the following statements is true under these conditions: The enzyme concentration is $5\ \mu$M, the substrate concentration is $5\ \mu$M, and the $K_m$ is $5\ \mu$M.

Accepted Answer

Half of the enzyme has substrate bound.

Question 11

Which types of inhibition can be reversed?

Accepted Answer

All of the above

Question 12

2,3-bisphosphoglycerate (2,3-BPG):

Accepted Answer

All of the above

Question 13

Which of the following statements is correct for hemoglobin and oxygen transport?

Accepted Answer

The binding of each $O_2$ molecule to hemoglobin increases its affinity for the next $O_2$ molecule.

Question 14

Fructose can cyclize to form:

Accepted Answer

both pyranose and furanose ring forms

Question 15

The following monosaccharide is shown: $\mathrm{CH_2OH}-(CHOH)_3-CHO$. What type of sugar is this?

Accepted Answer

aldopentose

Question 16

What can be said about the relationship of these two carbohydrate structures, which are mirror images of each other?

Accepted Answer

They are enantiomers.

Question 17

_____ is the structural material for plants while _____ is the energy storage material of plants.

Accepted Answer

cellulose/starch

Question 18

The longer the fatty acid, the _____ the fatty acid.

Accepted Answer

higher the melting point of

Question 19

The fluorescence recovery after photobleaching (FRAP) technique has been used to study:

Accepted Answer

All of the above

Question 20

Which of the following helps regulate membrane fluidity in animals?

Accepted Answer

cholesterol

Biochemistry Study Guide: Enzyme Kinetics, Carbohydrates, Lipids, Membranes, and Signal Transduction

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