Question 1

Which of the following best distinguishes between an aldose and a ketose sugar?

Accepted Answer

Aldoses contain an aldehyde group at the first carbon, while ketoses contain a ketone group at the second carbon.

Question 2

Which of the following is the correct formula for calculating the number of possible stereoisomers for a monosaccharide with $$n$$ chiral centers?

Accepted Answer

$$2^n$$

Question 3

A patient is diagnosed with lactose intolerance. Which enzyme is deficient, and what type of reaction does this enzyme catalyze?

Accepted Answer

Lactase; it catalyzes the hydrolysis of lactose into glucose and galactose.

Question 4

Which of the following statements about the reducing and non-reducing ends of a polysaccharide is correct?

Accepted Answer

The reducing end contains a free anomeric carbon that can act as a reducing agent.

Question 5

Which of the following best explains why unsaturated fatty acids tend to be liquid at room temperature?

Accepted Answer

The presence of double bonds introduces kinks, preventing tight packing of the fatty acid chains.

Question 6

Which of the following is a characteristic of amphipathic molecules such as phospholipids?

Accepted Answer

They contain both hydrophilic and hydrophobic regions.

Question 7

A triglyceride is formed by the esterification of which components?

Accepted Answer

One glycerol and three fatty acids

Question 8

Which of the following amino acids is most likely to be found in the interior of a globular protein?

Accepted Answer

Leucine

Question 9

Which level of protein structure is primarily stabilized by hydrogen bonds between backbone amide and carbonyl groups?

Accepted Answer

Secondary structure

Question 10

A mutation causes the substitution of a hydrophobic amino acid with a hydrophilic one in the core of a protein. What is the most likely consequence?

Accepted Answer

The protein may misfold or become unstable due to disruption of hydrophobic interactions.

Question 11

Which of the following best describes the difference between fibrous and globular proteins?

Accepted Answer

Fibrous proteins are generally structural and insoluble, while globular proteins are functional and soluble.

Question 12

Which of the following is the correct sequence of protein structural organization from simplest to most complex?

Accepted Answer

Primary → Secondary → Tertiary → Quaternary

Question 13

Which of the following best describes the Michaelis-Menten equation for enzyme kinetics?

Accepted Answer

$$v = \frac{V_{max}[S]}{K_m + [S]}$$

Question 14

In a Lineweaver-Burk plot, which type of enzyme inhibition increases the apparent $$K_m$$ but does not affect $$V_{max}$$?

Accepted Answer

Competitive inhibition

Question 15

Which of the following statements about enzyme catalysis is correct?

Accepted Answer

Enzymes lower the activation energy ($$E_a) of a $$reaction without changing the overall free energy change ($$\Delta G).$$

Question 16

Which of the following is a correct classification of the enzyme catalase based on the reaction it catalyzes?

Accepted Answer

Oxidoreductase

Question 17

Which of the following best explains why enzymes are highly specific for their substrates?

Accepted Answer

The active site of an enzyme has a unique three-dimensional structure that complements the substrate.

Question 18

Which of the following best describes the effect of a noncompetitive inhibitor on enzyme kinetics?

Accepted Answer

$$V_{max}$$ decreases, $$K_m$$ remains unchanged.

Question 19

Which of the following is a real-life example of a protein with quaternary structure?

Accepted Answer

Hemoglobin

Question 20

Which of the following best describes the process of saponification?

Accepted Answer

The hydrolysis of triglycerides by a base to produce glycerol and soap.

Biochemistry Exam Study Guide: Carbohydrates, Lipids, Proteins, and Enzymes

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