Biochemistry Fundamentals: Master the Building Blocks of Life

Question 1

Which of the following statements about enzymes is false?

Accepted Answer

They are consumed during the reactions they catalyze.

Answer

They are highly specific for their substrates.

Answer

They increase the rate of chemical reactions.

Answer

They are either proteins or RNA molecules.

Question 2

Which of the following statements about covalent bonds is incorrect?

Accepted Answer

Electrons are localized in orbitals.

Answer

Electrons are shared between atoms.

Answer

Bonds are typically strong and directional.

Answer

Energy is released when the bond is formed.

Question 3

Which of the following acids is a strong acid?

Accepted Answer

Hydrochloric acid

Answer

Acetic acid

Answer

Carbonic acid

Answer

Phosphoric acid

Question 4

In a spontaneous reaction, the free energy change is:

Accepted Answer

Negative

Answer

Positive

Answer

Zero

Answer

Indeterminate

Question 5

Which interaction is primarily responsible for the hydrophobic effect?

Accepted Answer

Van der Waals forces

Answer

Hydrogen bonding

Answer

Ionic bonding

Answer

Dipole-dipole interactions

Question 6

A molecule that carries both a positive and a negative charge is called a:

Accepted Answer

Glycine

Answer

Glucose

Answer

Sodium chloride

Answer

Water

Question 7

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

Accepted Answer

The sequence of amino acids

Answer

The arrangement of amino acids in space

Answer

The folding of the protein into its functional shape

Answer

The combination of multiple polypeptide chains

Question 8

Nonpolar amino acids are characterized by:

Accepted Answer

Having hydrophobic side chains

Answer

Having hydrophilic side chains

Answer

Interacting strongly with water

Answer

Being charged at physiological pH

Question 9

The primary function of buffers in biochemical systems is to:

Accepted Answer

Maintain a constant pH

Answer

Provide a source of protons

Answer

Neutralize acids and bases

Answer

Prevent the formation of precipitates

Question 10

Which of the following is NOT a fundamental particle of an atom?

Accepted Answer

Molecule

Answer

Proton

Answer

Electron

Answer

Neutron

Question 11

A covalent bond is formed by the sharing of electrons. Which of the following statements about covalent bonds is NOT correct?

Accepted Answer

Covalent bonds always involve the sharing of two electrons.

Answer

Covalent bonds involve the sharing of electrons between atoms.

Answer

Covalent bonds are typically stronger than ionic bonds.

Answer

Covalent bonds can be formed between atoms of the same element.

Question 12

The pH of a neutral solution is:

Accepted Answer

7

Answer

0

Answer

3

Answer

14

Question 13

Water is considered a polar molecule because:

Accepted Answer

It has a dipole moment due to the uneven distribution of electrons.

Answer

It has a symmetrical shape.

Answer

Its electrons are evenly distributed.

Answer

It readily dissolves ionic compounds.

Question 14

The change in free energy (ΔG) for a spontaneous reaction is:

Accepted Answer

Negative

Answer

Positive

Answer

Zero

Answer

Indeterminate

Question 15

Which of the following is considered a strong acid?

Accepted Answer

Hydrochloric acid

Answer

Acetic acid

Answer

Sodium hydroxide

Answer

Ammonium hydroxide

Question 16

The primary structure of a protein refers to its:

Accepted Answer

Linear sequence of amino acids

Answer

Three-dimensional shape

Answer

Functional site

Answer

Hydrogen bonding pattern

Question 17

Which of the following molecules is NOT classified as a carbohydrate?

Accepted Answer

Amino acid

Answer

Glucose

Answer

Ribose

Answer

Sucrose

Question 18

The process by which cells break down glucose for energy is known as:

Accepted Answer

Glycolysis

Answer

Krebs cycle

Answer

Electron transport chain

Answer

Oxidative phosphorylation

Question 19

In the context of biochemistry, which of these reactions is NOT commonly encountered?

Accepted Answer

Electrolysis

Answer

Hydrolysis

Answer

Condensation

Answer

Redox reactions

Question 20

How does the branched structure of glycogen contribute to its efficient storage and release of glucose in the body?

Accepted Answer

The branched structure of glycogen enhances storage and release of glucose.

Answer

The branched structure of glycogen impedes the enzymatic breakdown of glucose.

Answer

The branched structure of glycogen has minimal impact on glucose storage and release.

Question 21

Which of the following represents the smallest indivisible particle of an element that retains its chemical properties?

Accepted Answer

Atom

Answer

Molecule

Answer

Compound

Answer

Neutron

Question 22

Which type of chemical bond results from the attraction between oppositely charged ions?

Accepted Answer

Ionic bond

Answer

Metallic bond

Answer

Hydrogen bond

Answer

Covalent bond

Question 23

Which acid is classified as a strong acid?

Accepted Answer

Sulfuric acid

Answer

Acetic acid

Answer

Hydrofluoric acid

Answer

Carbonic acid

Question 24

Which substance exhibits uniform distribution of electrons around its molecular structure?

Accepted Answer

Methane

Answer

Ammonia

Answer

Ethanol

Answer

Water

Question 25

When a system transitions from a higher to a lower energy state, what is the sign of the free energy change?

Accepted Answer

Negative

Answer

Indeterminate

Answer

Zero

Answer

Positive

Question 26

Which characteristic is attributed to buffer solutions?

Accepted Answer

Resistance to pH changes upon the addition of small amounts of acid or base.

Answer

Maintenance of a constant pH of 7.0.

Answer

Behavior as either a strong acid or strong base.

Question 27

Which type of chemical reaction involves the transfer of electrons?

Accepted Answer

Redox reaction

Answer

Gas-forming reaction

Answer

Neutralization reaction

Answer

Precipitation reaction

Question 28

Which of the following is considered a macromolecule?

Accepted Answer

Polysaccharide

Answer

Sodium chloride

Answer

Hydrogen gas

Answer

Water

Question 29

The primary structure of a protein mainly refers to which aspect?

Accepted Answer

Sequence of amino acids

Answer

Presence of specific functional groups

Answer

Number of disulfide bonds

Answer

Overall three-dimensional shape

Question 30

Which of the following is the smallest fundamental unit of matter?

Accepted Answer

Atom

Answer

Electron

Answer

Molecule

Question 31

Which of the following interactions result in the formation of an ionic bond?

Accepted Answer

Transfer of electrons between atoms

Answer

Unequal sharing of electrons between atoms

Answer

Sharing of electrons between atoms

Question 32

Which of the following is a characteristic of water that contributes to its biological importance?

Accepted Answer

High heat capacity

Answer

Low dielectric constant

Answer

Low surface tension

Answer

Nonpolar nature

Question 33

Which of the following is true about exothermic reactions?

Accepted Answer

They release energy as heat

Answer

They require a catalyst to occur

Answer

They have a positive change in entropy

Answer

They are nonspontaneous

Question 34

Which of the following cofactors is essential for the activity of many dehydrogenases?

Accepted Answer

NAD+

Answer

ATP

Answer

Fe2+

Answer

Coenzyme A

Question 35

In an enzymatic reaction, the substrate binds to a specific region of the enzyme known as the...

Accepted Answer

Active site

Answer

Cofactor-binding site

Answer

Allosteric site

Answer

Regulatory site

Question 36

Which of the following is the correct order of complexity in metabolic pathways?

Accepted Answer

Glycolysis < Citric acid cycle < Electron transport chain

Answer

Electron transport chain < Citric acid cycle < Glycolysis

Answer

Citric acid cycle < Glycolysis < Electron transport chain

Answer

Glycolysis > Citric acid cycle > Electron transport chain

Question 37

The conversion of glucose to pyruvate in the absence of oxygen is known as...

Accepted Answer

Fermentation

Answer

Aerobic respiration

Answer

Glycolysis

Answer

Citric acid cycle

Question 38

Which of the following is the genetic material found in viruses?

Accepted Answer

Deoxyribonucleic acid (DNA) or Ribonucleic acid (RNA)

Answer

Carbohydrate

Answer

Protein

Question 39

Which of the following is not a subatomic particle found within an atom?

Accepted Answer

Photon

Answer

Electron

Answer

Neutron

Answer

Proton

Question 40

Which type of chemical bond results from the attraction between oppositely charged ions?

Accepted Answer

Ionic bond

Answer

Hydrogen bond

Answer

Covalent bond

Answer

Van der Waals force

Question 41

Which of the following is considered a weak acid?

Accepted Answer

Acetic acid

Answer

Sulfuric acid

Answer

Hydrochloric acid

Answer

Nitric acid

Question 42

Identify the molecule known as the primary energy currency of cells.

Accepted Answer

ATP

Answer

GTP

Answer

FAD

Answer

NADH

Question 43

Which of the following is a type of lipid?

Accepted Answer

Triglyceride

Answer

Protein

Answer

Nucleic acid

Answer

Polysaccharide

Question 44

What is the primary function of enzymes in biological systems?

Accepted Answer

Catalyze chemical reactions

Answer

Transport molecules across cell membranes

Answer

Regulate gene expression

Answer

Store genetic information

Question 45

Which of the following is a characteristic unique to living organisms?

Accepted Answer

Homeostasis

Answer

Non-reactivity

Answer

Inertness

Answer

Static existence

Question 46

Identify the process by which DNA is transcribed into RNA.

Accepted Answer

Transcription

Answer

Translation

Answer

Replication

Question 47

Which of the following is NOT a recognized type of chemical bond in biochemistry?

Accepted Answer

Ionic-covalent

Answer

Ionic

Answer

Covalent

Answer

Hydrogen

Question 48

Which of the following molecules has a polar structure, meaning it has a positive and negative end?

Accepted Answer

Water (H₂O)

Answer

Oxygen (O₂)

Answer

Methane (CH₄)

Answer

Carbon dioxide (CO₂)

Question 49

What is the pH of a solution with a hydrogen ion ([H+]) concentration of 10⁻⁴ M?

Accepted Answer

4

Answer

5

Answer

3

Answer

6

Question 50

Which of the following describes a buffer solution in biochemistry?

Accepted Answer

A solution containing a weak acid and its conjugate base.

Answer

A solution that can easily change its pH.

Answer

A solution with a high ionic strength.

Answer

A solution with a pH of 7.

Question 51

What is the primary role of enzymes in biochemical reactions?

Accepted Answer

To lower the activation energy of the reaction, speeding it up.

Answer

To increase the rate of the reaction by providing energy.

Answer

To prevent the reaction from occurring.

Answer

To produce the final product, acting as a catalyst.

Question 52

What is the process by which plants convert light energy into chemical energy, producing sugars?

Accepted Answer

Photosynthesis

Answer

Glycolysis

Answer

Krebs cycle

Answer

Respiration

Question 53

Which of the following is a defining characteristic of all living organisms?

Accepted Answer

They are capable of reproduction, creating offspring.

Answer

They are not composed of cells, the basic unit of life.

Answer

They are composed of metal or other inorganic materials.

Answer

They do not change over time, remaining static.