Question 1

Which of the following best describes the role of ATP in cellular reactions?

Accepted Answer

ATP provides energy to drive endergonic reactions by coupling them to exergonic hydrolysis.

Question 2

A scientist is studying the folding of a newly synthesized protein. Which of the following mechanisms is LEAST likely to assist in proper protein folding?

Accepted Answer

Ubiquitylation targeting the protein for degradation

Question 3

Which of the following statements about enzymes is CORRECT?

Accepted Answer

Enzymes lower the activation energy ($$E_a) $$but do not affect the equilibrium position.

Question 4

Which of the following is a biologically relevant non-covalent interaction that stabilizes protein tertiary structure?

Accepted Answer

Hydrogen bonds

Question 5

A mutation causes the loss of methylation marks on histone proteins in a region of DNA. What is the most likely effect on chromatin structure and gene expression?

Accepted Answer

Chromatin becomes less condensed and gene expression increases.

Question 6

Which of the following best explains why condensation reactions are important in the formation of macromolecules?

Accepted Answer

They join monomers by removing a water molecule, forming covalent bonds.

Question 7

Which of the following is TRUE regarding the three main categories of lipids in cells?

Accepted Answer

Steroids are important for membrane structure and signaling.

Question 8

Which amino acid is considered 'special' due to its ability to form disulfide bonds, stabilizing protein structure?

Accepted Answer

Cysteine

Question 9

A cell is exposed to a reducing agent. What is the most likely effect on protein structure?

Accepted Answer

Disulfide bonds are broken, potentially leading to denaturation.

Question 10

Which of the following best describes the relationship between chromatin compaction and transcription?

Accepted Answer

Highly compacted chromatin (heterochromatin) is generally transcriptionally inactive.

Question 11

Which of the following is a correct sequence of events in DNA replication?

Accepted Answer

Helicase unwinds DNA, primase synthesizes RNA primer, DNA polymerase extends the new strand.

Question 12

Which of the following is NOT a function of non-coding RNA in eukaryotic cells?

Accepted Answer

Encoding proteins

Question 13

Which of the following best describes the process of subcellular fractionation?

Accepted Answer

Separating cellular components based on size and density using centrifugation

Question 14

Which of the following statements about protein domains is CORRECT?

Accepted Answer

Domains are regions of a protein that fold independently and often have distinct functions.

Question 15

Which of the following best explains the significance of phosphorylation as a protein modification?

Accepted Answer

Phosphorylation can alter protein activity, localization, or interactions by adding a phosphate group.

Question 16

Which of the following is TRUE regarding the directionality of nucleic acids?

Accepted Answer

DNA and RNA are synthesized in the 5' to 3' direction.

Question 17

Which of the following best describes the role of fluorescently tagged probes in cell biology research?

Accepted Answer

They allow visualization of specific molecules or structures within cells.

Question 18

Which of the following is a plausible outcome of denaturation of a protein?

Accepted Answer

Loss of secondary, tertiary, and quaternary structure, but retention of primary structure.

Question 19

Which of the following best describes the relationship between Gibbs free energy ($$\Delta G) $$and spontaneity of a reaction?

Accepted Answer

A reaction is spontaneous if $$\Delta G \u003c 0.$$

Question 20

Which of the following is TRUE regarding the process of metabolic labeling?

Accepted Answer

It involves incorporating radioactive or fluorescent tags into newly synthesized molecules to track their fate.

BIO340 Cell Biology Study Guide: Chapters 1–5 (Proteins, DNA, Macromolecules, Energetics, Techniques)

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