Master Biochemistry Basics: Atoms, Molecules, and More

Question 1

Which of the following is NOT a characteristic of ionic bonds? They are:

Accepted Answer

Covalent

Answer

Formed between atoms of metals and non-metals

Answer

Produce electrically charged ions

Answer

Can form crystals

Question 2

Muscle pain after exercise is caused by the accumulation of which weak acid in muscle tissue?

Accepted Answer

Lactic acid

Answer

Pyruvic acid

Answer

Acetic acid

Answer

Citric acid

Question 3

A solution has a hydrogen ion concentration of 1 x 10^-4 M. What is its pH?

Accepted Answer

4

Answer

7

Answer

10

Answer

14

Question 4

Which of the following atoms has the highest electronegativity?

Accepted Answer

Fluorine

Answer

Sodium

Answer

Chlorine

Answer

Oxygen

Question 5

What is the empirical formula of a compound with a molecular formula of C6H12O6?

Accepted Answer

CH2O

Answer

C3H6O3

Answer

C2H4O2

Answer

C6H12O6

Question 6

Which of the following is NOT a property of lipids?

Accepted Answer

Act as enzymes

Answer

Insoluble in water

Answer

High energy density

Answer

Contain only carbon, hydrogen, and oxygen atoms

Question 7

What is the name of the process by which the genetic information encoded in DNA is converted into a protein?

Accepted Answer

Translation

Answer

Replication

Answer

Transcription

Answer

Polymerase chain reaction (PCR)

Question 8

How does hydrogen bonding contribute to the structural stability of proteins and nucleic acids?

Accepted Answer

Stabilizes tertiary and quaternary structures of proteins

Answer

Strengthens covalent bonds between nucleotides in nucleic acids

Answer

Solely responsible for the double-stranded structure of DNA

Answer

Weakens interactions between amino acids in proteins

Question 9

How do enzymes accelerate the rate of biochemical reactions?

Accepted Answer

By reducing the activation energy needed for the reaction.

Answer

By raising the temperature of the reaction.

Answer

By lowering the concentration of the reactants.

Answer

By changing the pH of the reaction.

Question 10

The correct symbol for the element potassium is:

Accepted Answer

K

Answer

Po

Answer

Pt

Answer

Pd

Question 11

When two atoms share electrons, what type of bond is formed?

Accepted Answer

Covalent bond

Answer

Ionic bond

Answer

Hydrogen bond

Answer

Van der Waals force

Question 12

The pH of human blood is approximately:

Accepted Answer

7.4

Answer

1

Answer

5.5

Answer

9

Question 13

Which of the following is not a characteristic of enzymes?

Accepted Answer

Combustibility

Answer

Specificity

Answer

Efficiency

Answer

Regulation

Question 14

The primary structure of a protein refers to:

Accepted Answer

The sequence of amino acids

Answer

The arrangement of secondary structures

Answer

The three-dimensional shape of the protein

Answer

The overall charge of the protein

Question 15

Which of the following best describes a molecule that can be represented by multiple valid Lewis structures?

Accepted Answer

Resonance hybrid

Answer

Transient structure

Answer

Single Lewis structure

Answer

Predictive structure

Question 16

What is the primary function of buffers in biological systems?

Accepted Answer

Stabilize pH by absorbing or releasing hydrogen ions

Answer

Prevent the formation of acids and bases

Answer

Function exclusively in acidic environments

Answer

Play no significant role in biological processes

Question 17

Which of the following correctly represents the chemical structure of water?

Accepted Answer

Two hydrogen atoms (H) covalently bonded to an oxygen atom (O), forming H-O-H

Answer

Two hydrogen atoms (H) covalently bonded to a hydrogen atom (H), forming H-H-O

Answer

Two oxygen atoms (O) covalently bonded to a hydrogen atom (H), forming O-H-H

Question 18

Ionic bonds are formed due to the electrostatic attraction between:

Accepted Answer

Oppositely charged ions

Answer

Positively charged ions and covalent bonds

Answer

Neutral atoms and van der Waals forces

Answer

Electrons and protons

Question 19

Which system is capable of resisting changes in pH when small amounts of acid or base are added?

Accepted Answer

A buffer system, composed of a weak acid and its conjugate base (or vice versa)

Answer

A solution of pure water

Answer

A solution of a strong acid and a strong base

Answer

A solution of a weak acid only

Question 20

Calculate the molar mass of sodium chloride (NaCl), given that the atomic mass of sodium (Na) is 22.99 g/mol and the atomic mass of chlorine (Cl) is 35.45 g/mol.

Accepted Answer

58.44 g/mol

Answer

22.99 g/mol

Answer

81.88 g/mol

Answer

35.45 g/mol

Question 21

Arrange the following chemical bonds in order of increasing strength: van der Waals forces, ionic bonds, hydrogen bonds, covalent bonds

Accepted Answer

Van der Waals forces < hydrogen bonds < ionic bonds < covalent bonds

Answer

Covalent bonds < ionic bonds < hydrogen bonds < van der Waals forces

Answer

Hydrogen bonds < van der Waals forces < ionic bonds < covalent bonds

Answer

Ionic bonds < hydrogen bonds < van der Waals forces < covalent bonds

Question 22

Identify the correct chemical formula for glucose, a monosaccharide sugar:

Accepted Answer

C6H12O6

Answer

C4H8O4

Answer

C5H10O5

Answer

C3H6O3

Question 23

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

Accepted Answer

Energy storage

Answer

Structural support

Answer

Immune response

Answer

Enzyme catalysis

Question 24

The primary structure of a protein refers to its:

Accepted Answer

Linear sequence of amino acids

Answer

Overall charge

Answer

Three-dimensional shape

Answer

Presence of disulfide bonds