Question 1

Which of the following statements best describes the role of biochemistry in higher organisms?

Accepted Answer

Biochemistry encompasses synthesis, breakdown, energy production, defenses, reproduction, communication, and environmental sensing.

Question 2

Which structural feature distinguishes eukaryotic cells from prokaryotic cells?

Accepted Answer

DNA organized as chromosomes within a nucleus.

Question 3

Organisms are classified by their energy and carbon sources. Which type of organism derives energy from chemical compounds and fixes carbon from $$CO_2$$?

Accepted Answer

Chemoautotroph

Question 4

Which of the following is a common theme among all cell types?

Accepted Answer

DNA is used for storage of genetic information.

Question 5

Gram-negative bacteria differ from gram-positive bacteria in which of the following ways?

Accepted Answer

Gram-negative bacteria have an outer membrane and a thinner peptidoglycan layer.

Question 6

Which cellular structure is responsible for the synthesis of proteins in both animal and plant cells?

Accepted Answer

Rough endoplasmic reticulum

Question 7

A bacterium is found living in an environment devoid of oxygen. How would you classify this organism?

Accepted Answer

Anaerobic prokaryote

Question 8

Which of the following statements about the cytoskeleton is correct?

Accepted Answer

The cytoskeleton is made of protein filaments and is highly dynamic.

Question 9

Which of the following is NOT a function of cellular macromolecules?

Accepted Answer

Nucleic acids are involved in most cellular reactions.

Question 10

Which element is NOT one of the four that compose more than 99% of the mass of any cell?

Accepted Answer

Sulfur

Question 11

Which functional group is commonly involved in forming covalent interactions or charge-charge interactions in biomolecules?

Accepted Answer

Sulfhydryl group

Question 12

Which statement best explains why most biological processes are stereospecific?

Accepted Answer

Enzymes recognize only one specific stereoisomer due to the arrangement of functional groups around chiral centers.

Question 13

Which equation correctly represents the relationship between Gibbs free energy, enthalpy, and entropy in biochemical reactions?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 14

A reaction in a cell has a positive $$\Delta G. $$Which strategy is commonly used by cells to make this reaction proceed?

Accepted Answer

Couple the reaction to a highly favorable reaction such as ATP hydrolysis.

Question 15

Which of the following is a correct description of the role of enzymes in cellular reactions?

Accepted Answer

Enzymes lower the transition state energy, increasing the rate of reaction.

Question 16

Which process describes the breakdown of large molecules into smaller ones in cellular metabolism?

Accepted Answer

Catabolism

Question 17

Which of the following correctly describes the flow of genetic information in a cell?

Accepted Answer

DNA is transcribed into mRNA, which is then translated into protein.

Question 18

Which base is present in RNA but not in DNA?

Accepted Answer

Uracil

Question 19

A mutation in DNA results in a new protein that functions better for the cell. What type of mutation is this?

Accepted Answer

Positive mutation

Question 20

Which evolutionary process is most likely responsible for the origin of eukaryotic cells according to the study materials?

Accepted Answer

Symbiotic relationships between prokaryotes

Foundations of Biochemistry: An Introduction to the Chemistry of Life

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