B. [Practice Questions] Part 2

Proverbs 16:3

c. To recognize sugars to defend against bacteria

What is the function of the lectins found in plants?
a. To synthesize carbohydrates from amino acids
b. To store energy in the form of starch
c. To recognize sugars to defend against bacteria
d. To act as a structural component of the cell wall

c. To transport oxygen to body cells and remove waste

Which of the following is a function of blood?
a. To store fat-soluble vitamins
b. To provide structural support for the body
c. To transport oxygen to body cells and remove waste
d. To produce hormones

c. Diabetes mellitus

Which of the following is described as a disease related to carbohydrate metabolism?
a. Anemia
b. Phenylketonuria (PKU)
c. Diabetes mellitus
d. Thrombocytopenia

b. It is the most common form found under physiologic conditions

Which of the following accurately describes a characteristic of the B-form of DNA?
a. It is similar to the B form but more compact
b. It is the most common form found under physiologic conditions
c. It is left-handed and has its bases positioned toward the periphery
d. It contains 12 base pairs per turn

• DNA polymerase III

  • DNA with lots of A and T bases separates at a lower temperature than DNA with many G and C bases.

In prokaryotic cells, which enzyme is primarily responsible for most of the DNA copying during replication?
a. The melting temperature is dependent on the length of the DNA molecule, but not its base composition.
b. DNA with a high percentage of G and C bases has a lower Tm.
c. DNA with lots of A and T bases separates at a lower temperature than DNA with many G and C bases.
d. The melting temperature is unrelated to base composition.

c. They are found in damaged lipoproteins and contribute to atherosclerosis

Which of the following is a role of lysophospholipids in the human body?
a. They help with nerve signal transmission
b. They act as a precursor for sex hormones
c. They are found in damaged lipoproteins and contribute to atherosclerosis
d. They are the main component of lung surfactant

c. By using sound waves to break up amphipathic lipids in water

Liposomes can be used to carry drugs and genes. How are they formed?
a. By mixing fatty acids with cholesterol
b. By heating amphipathic lipids in water
c. By using sound waves to break up amphipathic lipids in water
d. By creating a micelle with a hydrophobic interior

b. To hold the amino acid

What is the function of the CCA sequence at the 3' end of a tRNA molecule?
a. To bind to the ribosome
b. To hold the amino acid
c. To act as the anticodon
d. To form the D loop

a. Small, circular DNA molecules outside the chromosome that can copy themselves

The document describes plasmids in prokaryotic cells. Which of the following is an accurate description of a plasmid?
a. Small, circular DNA molecules outside the chromosome that can copy themselves
b. A large, linear DNA molecule that is the main chromosome
c. Histone proteins that DNA wraps around
d. A single, large chromosome in eukaryotic cells

d. DNA polymerase I

What is the process that removes the RNA primer and replaces it with the proper DNA nucleotides to fill the gap during DNA replication?
a. DNA polymerase III
b. DNA Primase
c. DNA Ligase
d. DNA polymerase I

c. Sulfur-containing amino acids

The formation of a black precipitate when a substance is treated with lead acetate indicates the presence of which type of amino acid?
a. Aromatic amino acids
b. Basic amino acids
c. Sulfur-containing amino acids
d. Hydroxyl-containing amino acids

a. Grease Spot Test

A translucent spot left on a piece of paper after a substance is applied and dried indicates a positive result for which test?
a. Grease Spot Test
b. Saponification Test
c. Acrolein Test
d. Sudan III/IV Test

a. To protect red blood cells from damage caused by certain chemicals

What is the function of the enzyme G6PD (glucose-6-phosphate dehydrogenase)?
a. To protect red blood cells from damage caused by certain chemicals
b. To produce red blood cells
c. To cause the breakdown of hemoglobin
d. To help blood clot

d. Kwashiorkor

Which disease is described as a severe lack of protein, even if calories are sufficient?
a. Galactosemia
b. Diabetes mellitus
c. Marasmus
d. Kwashiorkor

c. To link monosaccharide units together

What is the purpose of the glycosidic bond in carbohydrates?
a. To form a straight-chain structure
b. To make the sugar hydrophobic
c. To link monosaccharide units together
d. To reduce an aldehyde group to an alcohol

b. To transport oxygen to body cells and remove waste

Which of the following is a function of blood?
a. To store fat-soluble vitamins
b. To transport oxygen to body cells and remove waste
c. To produce hormones
d. To provide structural support for the body

a. It is the first antibody produced in response to an infection

According to the document, what is the main function of the pentameric antibody (IgM)?
a. It is the first antibody produced in response to an infection
b. It is the most abundant antibody, providing long-term immunity
c. It provides localized protection at mucosal surfaces
d. It mediates allergic reactions and protects against parasitic infections

c. Glycolipids

Which of the following complex lipids is made of a fatty acid, sphingosine, and a sugar?
a. Sphingophospholipids
b. Phosphoacylglycerols
c. Glycolipids
d. Glycerophospholipids

d. Liver glycogenolysis provides glucose to the bloodstream to maintain blood sugar, whereas muscle glycogenolysis provides energy for the muscle's own use during intense activity

Which of the following correctly describes a difference in the regulation of glycogenolysis between the liver and muscle cells?
a. Glycogenolysis is inhibited when glycogenesis occurs in the liver but not in muscle tissue
b. Liver glycogenolysis is primarily stimulated by adrenaline, while muscle glycogenolysis is regulated by insulin
c. Liver glycogenolysis is initiated by phosphorylase, but muscle glycogenolysis uses a different enzyme
d. Liver glycogenolysis provides glucose to the bloodstream to maintain blood sugar, whereas muscle glycogenolysis provides energy for the muscle's own use during intense activity

a. Hexokinase, phosphofructokinase, pyruvate kinase

The "irreversible" steps of glycolysis, which are bypassed during gluconeogenesis, are catalyzed by which set of enzymes?
a. Hexokinase, phosphofructokinase, pyruvate kinase
b. Pyruvate carboxylase, PEP carboxykinase, glucose-6-phosphatase
c. Aldolase, phosphoglycerate kinase, enolase
d. Triosephosphate isomerase, GAP dehydrogenase, phosphoglycerate mutase

c. Acetyl-CoA, which is used by the Krebs cycle

In the process of β-oxidation, what is the final product and its destination in the Krebs cycle?
a. Pyruvate, which is converted to acetyl-CoA for the Krebs cycle
b. Fatty acids, which are directly used in the Krebs cycle
c. Acetyl-CoA, which is used by the Krebs cycle
d. Ketone bodies, which are produced when the Krebs cycle is overloaded

b. DNA → RNA → Protein

What is the "central dogma of molecular biology"?
a. Transcription → Translation → Replication
b. DNA → RNA → Protein
c. Carbohydrates → Lipids → Proteins
d. ATP → ADP → AMP

a. Hexokinase has a high affinity for glucose and is active in states of low blood glucose, while glucokinase has a low affinity and is utilized in high-glucose states

Which of the following is a key regulatory difference between hexokinase and glucokinase?
a. Hexokinase has a high affinity for glucose and is active in states of low blood glucose, while glucokinase has a low affinity and is utilized in high-glucose states
b. Glucokinase is inhibited by its product, glucose-6-phosphate, while hexokinase is not
c. Glucokinase is used to phosphorylate glucose for entry into glycolysis, whereas hexokinase directs glucose into glycogenesis
d. Hexokinase is primarily found in the liver, while glucokinase is in most other tissues

b. Debranching enzyme

A specific enzyme in glycogenolysis is responsible for the hydrolysis of α1→6 linkages. What is the name of this enzyme?
a. Glycogen phosphorylase
b. Debranching enzyme
c. Phosphoglucomutase
d. Glycogen synthase

c. Phosphofructokinase (PFK)

In a situation of high ATP levels, which key regulatory enzyme of glycolysis is allosterically inhibited, leading to a decrease in its activity?
a. Hexokinase
b. Pyruvate kinase (PK)
c. Phosphofructokinase (PFK)
d. Enolase

a. A glycogen storage disease

A patient is found to have a buildup of glucose storage in their liver and muscles, leading to a metabolic disorder. This is most likely an example of:
a. A glycogen storage disease
b. Galactosemia
c. Lactose intolerance
d. Diabetes mellitus

b. To be a glycoprotein in human red blood cell membranes

What is the primary function of Glycophorin?
a. To act as a plant lectin to defend against bacteria
b. To be a glycoprotein in human red blood cell membranes
c. To aid in the synthesis of glycoproteins
d. To serve as an antibody to protect against infections

b. The bonds closest to the viewer are drawn as bold and thick

Which of the following is a key characteristic of the Haworth projection for cyclic glucose?
a. It shows the true three-dimensional chair shape of the ring
b. The bonds closest to the viewer are drawn as bold and thick
c. All hydrogen atoms are explicitly drawn
d. It shows the molecule from a top-down view

a. They are linked to the misfolding of soluble protein clumps

Which of the following statements about prion diseases is true?
a. They are linked to the misfolding of soluble protein clumps
b. They are caused by a virus
c. They are treated with antibiotics
d. They are always found in humans, but not animals

c. Africa, the Mediterranean, and Southeast Asia

A deficiency in a specific enzyme can cause red blood cells to burst when exposed to certain chemicals. This inherited condition is most common in people from which regions?
a. North America and Europe
b. South America and Australia
c. Africa, the Mediterranean, and Southeast Asia
d. East Asia and Russia

c. By using sound waves to break up amphipathic lipids in water

Liposomes can be used to carry drugs and genes. How are they formed?
a. By creating a micelle with a hydrophobic interior
b. By heating amphipathic lipids in water
c. By using sound waves to break up amphipathic lipids in water
d. By mixing fatty acids with cholesterol

b. Hydrogen bond, which dictates complementary base pairing

A particular type of bond is responsible for the strong linkage between DNA helices. Which type of bond is this, and what is its primary significance?
a. Glycosidic bond, which links a sugar and a nitrogen base
b. Hydrogen bond, which dictates complementary base pairing
c. Phosphodiester bond, which links nucleotide groups
d. Covalent bond, which is a strong linkage between DNA helicases

d. To relieve torsional strain by cutting and rejoining DNA strands

What is the role of Topoisomerase during DNA replication?
a. To synthesize a short RNA primer for DNA polymerase
b. To unwind the DNA helix at the replication fork
c. To add new DNA nucleotides to the RNA primer
d. To relieve torsional strain by cutting and rejoining DNA strands

d. It initiates the synthesis of RNA primers

What is the function of the enzyme DNA primase in DNA replication?
a. It relieves torsional strain in the DNA helix
b. It unwinds the DNA helix
c. It joins Okazaki fragments on the lagging strand
d. It initiates the synthesis of RNA primers

d. The codon containing the changed base codes for a different amino acid

A change in a single nucleotide base in a DNA sequence can result in a missense mutation. According to the document, what is the outcome of a missense mutation?
a. The genetic code is no longer nonoverlapping and commaless
b. The codon containing the changed base becomes a termination (stop) codon
c. The codon containing the changed base codes for the same amino acid
d. The codon containing the changed base codes for a different amino acid

a. To protect the mRNA from degradation and aid in its translation

What is the main function of the poly(A) tail on a eukaryotic mRNA molecule?
a. To protect the mRNA from degradation and aid in its translation
b. To act as a start codon for protein synthesis
c. To serve as an anticodon for tRNA
d. To attach a modified guanine to the start of the mRNA

c. The template strand moves from 3′ to 5′, and the pre-mRNA moves from 5′ to 3′

What is the correct reading direction for the template strand of DNA and the newly synthesized mRNA molecule during transcription in a eukaryotic cell?
a. The template strand moves from 5′ to 3′, and the pre-mRNA moves from 3′ to 5′
b. Both the template strand and the pre-mRNA move from 3′ to 5′
c. The template strand moves from 3′ to 5′, and the pre-mRNA moves from 5′ to 3′
d. Both the template strand and the pre-mRNA move from 5′ to 3′

c. To unwind the double-stranded DNA by pulling the strands apart

What is the role of helicase during DNA replication?
a. To relieve the positive supercoils that form ahead of the replication fork
b. To join Okazaki fragments together on the lagging strand
c. To unwind the double-stranded DNA by pulling the strands apart
d. To synthesize a short RNA primer to initiate DNA synthesis

a. DNA polymerases

Which type of enzyme is responsible for the polymerization of deoxynucleotides?
a. DNA polymerases
b. DNA ligase
c. Helicases
d. DNA primase

c. It undergoes apoptosis (programmed cell death)

What happens to a cell that has DNA damage that is too extensive to be repaired?
a. It undergoes a silent mutation
b. It enters the G0 resting phase
c. It undergoes apoptosis (programmed cell death)
d. It converts the damage into a harmless substance

d. The codon containing the changed base codes for the same amino acid.

What is the correct definition of a silent mutation as presented in the document?
a. The codon containing the changed base becomes a termination codon.
b. There is no change to the DNA sequence.
c. The codon containing the changed base codes for a different amino acid.
d. The codon containing the changed base codes for the same amino acid.

c. It is a structure where DNA is wrapped around a group of eight histone proteins.

Which of the following best describes the beads on a string nucleosomal structure of chromatin?
a. It is the most compact form of DNA packaging.
b. It is a structure where DNA is found in the nucleus, mitochondria, and chloroplasts.
c. It is a structure where DNA is wrapped around a group of eight histone proteins.
d. It is a linear chain of polynucleotides without any associated proteins.

a. Seliwanoff's Test

A test that differentiates ketoses from aldoses by forming a cherry red color is known as:
a. Seliwanoff's Test
b. Barfoed's Test
c. Benedict's Test
d. Bial's Test

b. Protein synthesis

The process where a cell creates proteins is described as being at the core of the "central dogma of molecular biology." What is this process called?
a. Transcription
b. Protein synthesis
c. Translation
d. DNA replication

c. It is a precursor for vitamin D.

Which of the following is a function of cholesterol mentioned in the document?
a. It is a component of bacterial cell membranes.
b. It serves as a primary source of stored energy.
c. It is a precursor for vitamin D.
d. It helps in the biosynthesis of glycoproteins.

c. T-cells and natural killer cells

A plant lectin called Concanavalin A can activate which of the following immune cells, according to the document?
a. Macrophages
b. Mast cells
c. T-cells and natural killer cells
d. B-cells

d. Liver glycogenolysis provides glucose to the bloodstream to maintain blood sugar, whereas muscle glycogenolysis provides energy for the muscle's own use during intense activity.

Which of the following statements correctly describes a difference in the regulation of glycogenolysis between the liver and muscle cells?
a. Liver glycogenolysis is primarily stimulated by adrenaline, while muscle glycogenolysis is regulated by insulin.
b. Glycogenolysis is inhibited when glycogenesis occurs in the liver but not in muscle tissue.
c. Liver glycogenolysis is initiated by phosphorylase, but muscle glycogenolysis uses a different enzyme, acid alpha glucosidase.
d. Liver glycogenolysis provides glucose to the bloodstream to maintain blood sugar, whereas muscle glycogenolysis provides energy for the muscle's own use during intense activity.

a. Lysozyme

Select the enzyme that hydrolyzes bacterial cell walls.
a. Lysozyme
b. Lactate dehydrogenase
c. Carbonic anhydrase
d. Kinase

b. Norepinephrine, Epinephrine, Dopamine

The amino acid Tyrosine is converted to catecholamines. These are:
a. Epinephrine, Dopamine
b. Norepinephrine, Epinephrine, Dopamine
c. Norepinephrine and Epinephrine
d. Norepinephrine, Dopamine

d. IgG

The most abundant of the serum immunoglobulins is:
a. IgM
b. IgA
c. IgE
d. IgG

c. The release of fatty acids and their subsequent beta-oxidation is a primary source of metabolic energy for the cell.

Which of the following statements best describes fatty acid metabolism?
a. Fatty acids and their CoA esters can freely cross the inner mitochondrial membrane.
b. Fatty acid metabolism is not related to carbohydrate metabolism.
c. The release of fatty acids and their subsequent beta-oxidation is a primary source of metabolic energy for the cell.
d. Fatty acid catabolism is not under hormonal control.

a. Achievement of a high absolute rate of reaction that is suitable for integration with other physiological processes.

Analyze the mechanism or catalytic strategy employed by carbonic anhydrase.
a. Achievement of a high absolute rate of reaction that is suitable for integration with other physiological processes.
b. Attainment of a high degree of specificity.
c. Utilization of the free energy associated with the hydrolysis of ATP.
d. Promotion of a reaction that is immeasurably slow at neutral pH.

c. Glycerol, lactate, pyruvate, glycogenic amino acids

Identify the precursors of gluconeogenesis.
a. Glycerol, lactic acid, pyruvic acid
b. Sucrose, lactic acid, pyruvic acid
c. Glycerol, lactate, pyruvate, glycogenic amino acids
d. Pyruvic acid, lactic acid, acetic acid

Citric Acid

Select the carbohydrate used as an acidulant, especially in infant feeding formulas:
a. Mannitol
b. Citric Acid
c. Tartaric Acid
d. Lactic Acid

a. Codon from mRNA

Determines amino acid sequence:
a. Codon from mRNA
b. Anticodon from tRNA
c. Peptide bond
d. Codon from DNA

d. Stereoisomers that differ in configuration at one specific carbon atom

Epimers are:
a. Monosaccharides
b. Enantiomers
c. Structural isomers
d. Stereoisomers that differ in configuration at one specific carbon atom

a. Substitution

Nucleotide sequence → identify type of mutation:
a. Substitution
b. Insertion
c. No mutation
d. Deletion

1-deoxy-D-xylulose-5-phosphate

Intermediate product of MEP that acts as a stress regulator:
a. 1-deoxy-D-xylulose-5-phosphate
b. Methylerythritol cyclodiphosphate
c. 1-deoxy-L-xylulose-5-phosphate
d. Isopentenyl diphosphate

Ubiquitin ligase (C-O)

Correct bonds formed by ligases:
a. Acyl CoA synthetase (C-O)
b. Pyruvate carboxylase (C-C)
c. Ubiquitin ligase (C-O)
d. Aminoacyl tRNA synthetase (C-S)

b. Prosthetic group

Which of the following terms BEST describes a cofactor that is firmly bound to an apoenzyme?
a. Cofactor
b. Prosthetic group
c. Holoenzyme
d. Transferase

a. Insulin

Compound that inhibits glycogenolysis:
a. Insulin
b. Glucagon
c. Cortisol
d. Epinephrine

d. Metabolic Syndrome

Which condition is characterized by a cluster of conditions including insulin resistance and hypertension?
a. Diabetes Mellitus
b. Glycogen Storage Diseases
c. Lactose Intolerance
d. Metabolic Syndrome

b. Cardiovascular disease

Chronic glycemia can lead to which of the following complications?
a. Enhanced kidney function
b. Cardiovascular disease
c. Improved immune function
d. Reduced blood pressure

c. Marasmus

Which condition results from severe energy deficiency and is characterized by weight loss and muscle wasting?
a. Kwashiorkor
b. Cystic Fibrosis
c. Marasmus
d. Sickle Cell Disease

a. CFTR gene

Cystic Fibrosis is caused by mutations in which gene?
a. CFTR gene
b. APC gene
c. HTT gene
d. BRCA1 gene

b. Sickle Cell Disease

Which disease is caused by a mutation in the hemoglobin gene, leading to sickle shaped red blood cells?
a. Hemophilia
b. Sickle Cell Disease
c. Thalassemia
d. Anemia

a. Accumulation of fat in the liver unrelated to alcohol

Which of the following is a characteristic of Non-Alcoholic Fatty Liver Disease (NAFLD)?
a. Accumulation of fat in the liver unrelated to alcohol
b. Linked to autoimmune disorders
c. Caused by hepatitis virus
d. Related to excessive alcohol consumption

a. CAG repeat expansion

Huntington’s Disease is characterized by what type of genetic mutation?
a. CAG repeat expansion
b. Point mutation
c. Deletion
d. Translocation

b. Collagen

Ehlers-Danlos Syndrome is primarily linked to defects in which protein?
a. Elastin
b. Collagen
c. Keratin
d. Myosin

d. Glycogen has branched every 12–15 glucose units, while amylopectin has branched every 24–30 units.

Glycogen and Amylopectin are both branched polysaccharides. What is a key structural difference between them?
a. Amylopectin has more frequent branches than glycogen.
b. Glycogen has α1→6 bonds, while amylopectin only has α1→4 bonds.
c. Amylopectin is an animal starch, while glycogen is a plant starch.
d. Glycogen has branched every 12–15 glucose units, while amylopectin has branched every 24–30 units.