Q: Which of the following is the correct order of information flow in a cell according to the central dogma?

$$DNA \rightarrow RNA \rightarrow \text{protein}$$

Question 1

Which of the following best describes the primary structure of a protein?

Accepted Answer

The sequence of amino acids linked by peptide bonds.

Question 2

A mutation causes a single amino acid substitution in hemoglobin, resulting in sickle-cell disease. Which level of protein structure is directly affected by this mutation?

Accepted Answer

Primary structure

Question 3

Which type of protein is responsible for accelerating chemical reactions in living organisms?

Accepted Answer

Enzymatic proteins

Question 4

What is the correct formula for the peptide bond formed between two amino acids?

Accepted Answer

A peptide bond is formed by a dehydration reaction between the carboxyl group ($$-COOH) of $$one amino acid and the amino group ($$-NH_2$) of another, resulting in -CO-NH$$-$$ linkage.

Question 5

Which of the following is NOT a function of proteins in living cells?

Accepted Answer

Energy storage in the form of glycogen

Question 6

A protein loses its three-dimensional structure when exposed to high temperature. What is this process called?

Accepted Answer

Denaturation

Question 7

Which of the following correctly matches a protein type with its function?

Accepted Answer

Transport protein – moves substances across cell membranes

Question 8

Which component of an amino acid determines its unique chemical properties?

Accepted Answer

The side chain (R group)

Question 9

Which of the following statements about quaternary protein structure is correct?

Accepted Answer

It involves the interaction of two or more polypeptide subunits.

Question 10

Which protein is responsible for the contraction of muscles?

Accepted Answer

Actin and myosin

Question 11

Which of the following best explains why proteins are considered versatile macromolecules?

Accepted Answer

They perform a wide range of functions including catalysis, defense, transport, communication, movement, and structural support.

Question 12

Which of the following is a real-world example of a receptor protein function?

Accepted Answer

Detecting signaling molecules released by other nerve cells

Question 13

If a protein is exposed to a drastic change in pH, what is most likely to happen?

Accepted Answer

The protein will denature and lose its biological activity.

Question 14

Which of the following is the correct order of information flow in a cell according to the central dogma?

Accepted Answer

$$DNA ightarrow RNA ightarrow 	ext{protein}$$

Question 15

Which of the following is a correct description of a nucleotide found in nucleic acids?

Accepted Answer

A nucleotide consists of a phosphate group, a five-carbon sugar, and a nitrogenous base.

Question 16

Which nitrogenous base is found only in RNA and not in DNA?

Accepted Answer

Uracil (U)

Question 17

Which of the following best describes the backbone of a nucleic acid?

Accepted Answer

A sugar-phosphate backbone

Question 18

Which type of bond joins the nitrogenous bases in a DNA double helix?

Accepted Answer

Hydrogen bonds

Question 19

Which of the following is a function of defensive proteins?

Accepted Answer

Inactivating and destroying viruses and bacteria

Question 20

A scientist is studying the expression of proteins in a cell. Which field of study is most relevant to this research?

Accepted Answer

Proteomics

Proteins and Nucleic Acids: Structure, Function, and Biological Roles

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