Introduction to Biochemistry: Master the Fundamentals of Life's Chemistry

Question 1

Which biomolecule consists of a nitrogenous base, a five-carbon sugar, and a phosphate group?

Accepted Answer

Nucleotide

Answer

Amino acid

Answer

Carbohydrate

Question 2

Which characteristic is NOT associated with carbohydrates?

Accepted Answer

Storage of genetic information

Answer

Source of energy

Answer

Component of cell membranes

Answer

Composition of carbon, hydrogen, and oxygen

Question 3

Which type of bond connects amino acids to form proteins?

Accepted Answer

Peptide bond

Answer

Glycosidic bond

Answer

Phosphodiester bond

Answer

Hydrogen bond

Question 4

What is the primary function of enzymes in biochemical reactions?

Accepted Answer

Lowering the activation energy of the reaction

Answer

Increasing the activation energy of the reaction

Answer

Providing an alternative pathway for the reaction

Answer

Consuming the products of the reaction

Question 5

What is the process called by which cells convert glucose into energy?

Accepted Answer

Glycolysis

Answer

Krebs cycle

Answer

Electron transport chain

Answer

Photosynthesis

Question 6

What is the primary role of ATP in biochemical reactions?

Accepted Answer

Energy currency of the cell

Answer

Electron carrier

Answer

Coenzyme

Answer

Hormone

Question 7

What is the fundamental structural level of a protein?

Accepted Answer

The sequence of amino acids

Answer

The folding of the protein into a specific shape

Answer

The interactions between different amino acids

Answer

The presence of prosthetic groups

Question 8

Which type of metabolic pathway involves the breakdown of molecules?

Accepted Answer

Catabolism

Answer

Anabolism

Answer

Gluconeogenesis

Answer

Glycogenolysis

Question 9

How does gene expression regulation contribute to cell specialization?

Accepted Answer

It enables the expression of specific genes, shaping the unique characteristics of different cell types.

Answer

It occurs independently of cell differentiation, happening randomly in all cells regardless of their function.

Answer

It suppresses gene expression in all cells, preventing differentiation and keeping cells in an undifferentiated state.

Question 10

Which of the following is NOT a characteristic of biological molecules?

Accepted Answer

Simple composition

Answer

High molecular weight

Answer

Complex structure

Answer

Essential for life processes

Question 11

What is the primary function of enzymes in biochemical reactions?

Accepted Answer

To decrease the activation energy of the reaction

Answer

To increase the activation energy of the reaction

Answer

To provide energy for the reaction

Answer

To remove products from the reaction

Question 12

Which of the following is the monomeric unit of proteins?

Accepted Answer

Amino acids

Answer

Nucleotides

Answer

Monosaccharides

Answer

Fatty acids

Question 13

What is the central dogma of molecular biology?

Accepted Answer

DNA → RNA → Protein

Answer

RNA → DNA → Protein

Answer

Protein → RNA → DNA

Answer

DNA → Protein → RNA

Question 14

Which of the following is a reducing agent commonly used in biochemical experiments?

Accepted Answer

Sodium borohydride

Answer

Sodium chloride

Answer

Ethanol

Answer

Hydrochloric acid

Question 15

What is the primary function of mitochondria in cells?

Accepted Answer

To produce energy

Answer

To store genetic material

Answer

To synthesize proteins

Answer

To regulate cell growth

Question 16

What is the purpose of PCR (Polymerase Chain Reaction)?

Accepted Answer

To amplify a specific region of DNA in vitro

Answer

To sequence DNA

Answer

To translate RNA into protein

Answer

To modify gene expression

Question 17

Which of the following is NOT considered a primary biological molecule?

Accepted Answer

Vitamins

Answer

Carbohydrates

Answer

Lipids

Answer

Proteins

Question 18

What is the predominant role of carbohydrates in cellular metabolism?

Accepted Answer

Energy provision and structural support

Answer

Hormonal regulation and cell signaling

Answer

Genetic information storage and transmission

Answer

Enzyme catalysis and molecular transport

Question 19

Which of the following amino acids is classified as nonpolar?

Accepted Answer

Alanine

Answer

Serine

Answer

Aspartic acid

Answer

Glutamic acid

Question 20

What is the primary function of enzymes in biochemical reactions?

Accepted Answer

To decrease the activation energy of reactions

Answer

To increase the activation energy of reactions

Answer

To provide the reactants for reactions

Answer

To remove the products of reactions

Question 21

Which of the following is NOT a recognized stage of gene expression?

Accepted Answer

Replication

Answer

Transcription

Answer

Translation

Answer

Protein folding

Question 22

Which metabolic pathway is primarily responsible for generating ATP in most organisms?

Accepted Answer

Oxidative phosphorylation

Answer

Glycolysis

Answer

Citric acid cycle

Answer

Gluconeogenesis

Question 23

What is the primary function of the ribosome in protein synthesis?

Accepted Answer

To translate mRNA into a polypeptide chain

Answer

To synthesize mRNA from DNA

Answer

To fold and modify the newly synthesized protein

Answer

To transport the protein to its destination

Question 24

In cellular respiration, how does the citric acid cycle provide electrons to the electron transport chain?

Accepted Answer

The citric acid cycle generates NADH and FADH2, which donate electrons to the electron transport chain.

Answer

Oxaloacetate from the citric acid cycle directly enters the electron transport chain.

Answer

The electron transport chain produces carbon dioxide, which is released during the citric acid cycle.

Answer

The citric acid cycle and the electron transport chain occur in different compartments of the cell.

Question 25

Which type of bond primarily contributes to the primary structure of proteins?

Accepted Answer

Covalent peptide bonds

Answer

Hydrogen bonds

Answer

Ionic bonds

Answer

Van der Waals interactions

Question 26

Which of the following components serves as the fundamental unit of carbohydrates?

Accepted Answer

Monosaccharides

Answer

Amino acids

Answer

Nucleotides

Answer

Fatty acids

Question 27

What is the essential role of enzymes in biochemical reactions?

Accepted Answer

Lower the activation energy of the reaction

Answer

Raise the activation energy of the reaction

Answer

Provide the reactants for the reaction

Answer

Eliminate the products of the reaction

Question 28

Which of the following accurately describes the fundamental principle of molecular biology?

Accepted Answer

DNA → RNA → Protein

Answer

Protein → RNA → DNA

Answer

RNA → DNA → Protein

Answer

DNA → Protein → RNA

Question 29

Within protein synthesis, what is the primary function of the ribosome?

Accepted Answer

Assemble amino acids into a polypeptide chain

Answer

Synthesize amino acids

Answer

Transport mRNA to the cytoplasm

Answer

Proofread the newly synthesized protein

Question 30

Which molecule serves as the cell's energy currency?

Accepted Answer

ATP

Answer

NADH

Answer

FAD

Answer

Glycogen

Question 31

What is the primary purpose of the citric acid cycle?

Accepted Answer

Produce NADH and FADH2

Answer

Generate ATP

Answer

Oxidize glucose

Answer

Synthesize amino acids

Question 32

Which of the following properties is not characteristic of carbohydrates?

Accepted Answer

Carry a net positive charge

Answer

Consist of carbon, hydrogen, and oxygen atoms

Answer

Serve as a primary source of energy

Answer

Can have branched or unbranched structures

Question 33

Which unit serves as the building block of proteins?

Accepted Answer

Amino acid

Answer

Monosaccharide

Answer

Fatty acid

Answer

Nucleotide

Question 34

Which type of bond is responsible for establishing the primary structure of proteins?

Accepted Answer

Covalent bond

Answer

Ionic bond

Answer

Hydrogen bond

Answer

Disulfide bond

Question 35

Which metabolic pathway involves the breakdown of complex molecules into simpler substances?

Accepted Answer

Catabolism

Answer

Anabolism

Answer

Glycolysis

Answer

Gluconeogenesis

Question 36

What molecule acts as the electron acceptor during cellular respiration?

Accepted Answer

Oxygen

Answer

Carbon dioxide

Answer

Water

Answer

Glucose

Question 37

Where does protein synthesis take place within cells?

Accepted Answer

Ribosome

Answer

Nucleus

Answer

Mitochondria

Answer

Golgi apparatus

Question 38

Which nitrogenous base is not found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Thymine

Answer

Cytosine

Question 39

Which biological molecule is primarily responsible for carrying genetic information?

Accepted Answer

Nucleic acids

Answer

Carbohydrates

Answer

Proteins

Answer

Lipids

Question 40

What type of chemical bond links amino acids to form a polypeptide chain?

Accepted Answer

Covalent bond

Answer

Hydrogen bond

Answer

Ionic bond

Answer

Van der Waals force

Question 41

Which concept accurately describes the central dogma of molecular biology?

Accepted Answer

Genetic information flows from DNA to RNA to protein

Answer

Genetic information flows from RNA to DNA to protein

Answer

Genetic information flows from protein to DNA to RNA

Answer

Genetic information flows from DNA to protein to RNA

Question 42

What is the primary function of enzymes in biochemical reactions?

Accepted Answer

To lower the activation energy required for reactions to occur

Answer

To increase the activation energy required for reactions to occur

Answer

To directly produce new chemical compounds in reactions

Answer

To consume energy in order for reactions to take place

Question 43

Which molecule serves as the primary energy currency in cells?

Accepted Answer

ATP

Answer

Glucose

Answer

NADH

Answer

Acetyl-CoA

Question 44

Which of the following amino acids is classified as branched-chain?

Accepted Answer

Leucine

Answer

Glycine

Answer

Tryptophan

Answer

Asparagine

Question 45

What is the term used to describe the sequence of bases in DNA that determines the sequence of amino acids in a protein?

Accepted Answer

Genetic code

Answer

Protein sequence

Answer

Transcription code

Answer

Translation code

Question 46

Which structural level of protein organization involves the sequence of amino acids connected by peptide bonds?

Accepted Answer

Primary structure

Answer

Secondary structure

Answer

Tertiary structure

Answer

Quaternary structure

Question 47

Which biomolecule serves as the primary carrier of genetic information and exhibits a double helix structure?

Accepted Answer

Nucleic acid

Answer

Carbohydrate

Answer

Protein

Answer

Lipid

Question 48

Which of these is NOT considered a biological macromolecule?

Accepted Answer

Vitamins

Answer

Carbohydrates

Answer

Proteins

Answer

Lipids

Question 49

Which of the following properties is NOT characteristic of carbohydrates?

Accepted Answer

Solubility in nonpolar solvents

Answer

Ability to exist as polymers or monomers

Answer

Role in providing energy

Question 50

During the hydrolysis of a peptide bond, the bond that is broken is between:

Accepted Answer

The carbonyl carbon and the amino nitrogen

Answer

The amino nitrogen and the hydrogen

Answer

The carboxyl carbon and the oxygen

Answer

The carbonyl carbon and the carboxyl carbon

Question 51

Kinases are a type of enzyme that catalyzes:

Accepted Answer

Transfer of phosphate groups

Answer

Hydrolysis of glycosidic bonds

Answer

Transfer of electrons

Question 52

The process by which cells convert glucose into ATP is known as:

Accepted Answer

Glycolysis

Answer

Photosynthesis

Answer

Gluconeogenesis

Answer

Citric acid cycle

Question 53

Which molecule is NOT directly involved in the process of DNA replication?

Accepted Answer

RNA polymerase

Answer

DNA polymerase

Answer

Helicase

Question 54

The primary structure of a protein refers to its:

Accepted Answer

Sequence of amino acids

Answer

Three-dimensional shape

Answer

Interactions with other molecules

Answer

Number of peptide bonds

Question 55

The process by which plants convert carbon dioxide and water into glucose is:

Accepted Answer

Photosynthesis

Answer

Respiration

Answer

Citric acid cycle

Answer

Glycolysis

Question 56

Which of the following is classified as a nucleic acid?

Accepted Answer

RNA

Answer

Lipid

Answer

Carbohydrate

Answer

Protein