$$\text{Mass number} = \text{number of protons} + \text{number of neutrons}$$

Question 1

Which of the following is NOT a characteristic shared by all living organisms?

Accepted Answer

They are all multicellular.

Question 2

Which of the following elements is NOT one of the six that make up approximately 98% of all living matter?

Accepted Answer

Calcium (Ca)

Question 3

A neutral atom of carbon has an atomic number of 6. How many electrons does it have?

Accepted Answer

6

Question 4

Which macromolecule is primarily responsible for catalyzing biochemical reactions in cells?

Accepted Answer

Proteins

Question 5

Which functional group is important for stabilizing protein structure by forming disulfide bridges?

Accepted Answer

Sulfhydryl group ($$\mathrm{-SH})$$

Question 6

Which of the following best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Question 7

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 8

Which class of biomolecule is primarily involved in energy conversion and cell recognition?

Accepted Answer

Simple sugars (carbohydrates)

Question 9

A molecule of deuterium ($$^2\mathrm{H}) $$contains:

Accepted Answer

1 proton, 1 neutron, 1 electron

Question 10

Which property is associated with the methyl functional group ($$\mathrm{-CH_3$}$$)?

Accepted Answer

Nonpolar; important in interacting with other nonpolar molecules and in energy transfer.

Question 11

Which of the following best explains why most biochemical reactions take place in aqueous solutions?

Accepted Answer

Water is the most abundant molecule in living tissues, facilitating molecular interactions.

Question 12

Which of the following is the correct formula for calculating the mass number of an atom?

Accepted Answer

$$	ext{Mass number} = 	ext{number of protons} + 	ext{number of neutrons}$$

Question 13

Which of the following functional groups is most likely to participate in energy transfer reactions, such as those involving ATP?

Accepted Answer

Phosphate group ($$\mathrm{-PO_4$})$$

Question 14

Which macromolecule is the primary component of biological membranes?

Accepted Answer

Lipids

Question 15

A patient is diagnosed with a genetic disorder affecting the synthesis of nucleic acids. Which biomolecule is most directly impacted?

Accepted Answer

Nucleotides

Question 16

Which of the following best describes the universal molecular code used by living organisms to synthesize proteins?

Accepted Answer

The sequence of nucleotides in DNA and RNA

Question 17

Which of the following is a real-life application of the importance of functional groups in biochemistry?

Accepted Answer

The sulfhydryl group ($$\mathrm{-SH}) in $$cysteine residues forms disulfide bonds, stabilizing insulin structure.

Introduction to Biochemistry: Building Blocks of Cells and Atoms

Study Guide - Practice Questions