Protein Metabolism: Interactive Learning Quizzes for Medical Students

Question 1

Identify the essential amino acid for humans:

Accepted Answer

Histidine

Answer

Alanine

Answer

Asparagine

Answer

Glutamine

Question 2

Which mechanism is not involved in protein degradation?

Accepted Answer

Glycosylation

Answer

Ubiquitin-proteasome pathway

Answer

Lysosomal degradation

Answer

Autolysis

Question 3

What molecule determines the amino acid sequence of a protein?

Accepted Answer

mRNA

Answer

rRNA

Answer

tRNA

Answer

DNA

Question 4

In genetics, a codon consists of how many nucleotides?

Accepted Answer

3

Answer

1

Answer

2

Answer

4

Question 5

Which of the following amino acids is not considered essential for humans?

Accepted Answer

Alanine

Answer

Lysine

Answer

Methionine

Answer

Valine

Question 6

In eukaryotic cells, where does the majority of protein synthesis take place?

Accepted Answer

Ribosome

Answer

Cytoplasm

Answer

Mitochondria

Answer

Nucleus

Question 7

Which enzyme initiates protein translation by binding to the start codon?

Accepted Answer

Initiation factor 2

Answer

Peptidyl transferase

Answer

RNA polymerase

Answer

Aminoacyl tRNA synthetase

Question 8

Which hormone is known to play a significant role in regulating protein synthesis?

Accepted Answer

Insulin

Answer

Cortisol

Answer

Epinephrine

Answer

Glucagon

Question 9

What is the term for the process of breaking down proteins into smaller peptides?

Accepted Answer

Proteolysis

Answer

Catabolism

Answer

Degradation

Answer

Hydrolysis

Question 10

Which of the following is an example of an inherited disorder related to amino acid metabolism?

Accepted Answer

Phenylketonuria

Answer

Cystic fibrosis

Answer

Down syndrome

Answer

Sickle cell disease

Question 11

In protein metabolism, what is the main role of transcription factors in regulating gene expression?

Accepted Answer

Triggering gene transcription by activating promoters and enhancers

Answer

Changing chromatin structure by modifying histones

Answer

Preventing protein translation by degrading mRNA

Answer

Creating different protein isoforms by splicing pre-mRNA

Question 12

How do molecular chaperones facilitate protein folding, particularly for newly synthesized proteins?

Accepted Answer

Bind to exposed hydrophobic regions, preventing aggregation and promoting correct folding.

Answer

Provide energy from ATP hydrolysis to drive protein folding.

Answer

Act as templates for protein folding by guiding the polypeptide chain into its native conformation.

Answer

Are only required for the folding of secretory proteins.

Question 13

Which enzyme initiates the degradation pathway for branched-chain amino acids?

Accepted Answer

Branched-chain ketoacid dehydrogenase

Answer

Proteasome

Answer

Pepsin

Answer

Trypsin

Question 14

Which amino acid residue contributes significantly to maintaining the tertiary protein structure?

Accepted Answer

Cysteine

Answer

Asparagine

Answer

Glutamine

Answer

Methionine

Question 15

Which technique is commonly employed to separate proteins based on their electrical charge?

Accepted Answer

Electrophoresis

Answer

Chromatography

Answer

Centrifugation

Answer

Precipitation

Question 16

Which hormone triggers protein breakdown?

Accepted Answer

Cortisol

Answer

Insulin

Answer

Glucagon

Answer

Estrogen

Question 17

Which condition results from a phenylalanine hydroxylase enzyme deficiency?

Accepted Answer

Phenylketonuria

Answer

Albinism

Answer

Sickle cell anemia

Answer

Cystic fibrosis

Question 18

Which of the following enzymes is responsible for the initial step in the breakdown of dietary proteins in the stomach?

Accepted Answer

Pepsin

Answer

Carboxypeptidase

Answer

Chymotrypsin

Answer

Trypsin

Question 19

What is the primary role of the urea cycle?

Accepted Answer

To remove ammonia from the body

Answer

To regulate blood glucose levels

Answer

To break down fatty acids

Answer

To synthesize amino acids

Question 20

Which of the following amino acids is considered essential and cannot be synthesized by the human body?

Accepted Answer

Lysine

Answer

Aspartate

Answer

Glutamate

Answer

Alanine

Question 21

What is the main function of tRNA in protein synthesis?

Accepted Answer

To carry specific amino acids to the ribosome

Answer

To act as a template for protein synthesis

Answer

To regulate gene expression

Answer

To initiate protein synthesis

Question 22

Which of the following is a key regulatory enzyme in glycolysis that is also involved in the synthesis of glucose from non-carbohydrate sources (gluconeogenesis)?

Accepted Answer

Pyruvate carboxylase

Answer

Glyceraldehyde-3-phosphate dehydrogenase

Answer

Hexokinase

Answer

Phosphofructokinase-1

Question 23

A patient presents with a deficiency in the enzyme phenylalanine hydroxylase. This leads to an accumulation of phenylalanine in the body. Which condition does this patient likely have?

Accepted Answer

Phenylketonuria (PKU)

Answer

Albinism

Answer

Maple syrup urine disease

Answer

Galactosemia

Question 24

Which of the following pathways is responsible for the breakdown of branched-chain amino acids (BCAAs)?

Accepted Answer

Branched-chain alpha-ketoacid dehydrogenase complex (BCKDH)

Answer

Krebs cycle

Answer

Urea cycle

Question 25

The ubiquitin-proteasome system is primarily involved in which process?

Accepted Answer

Protein degradation

Answer

RNA transcription

Answer

Protein synthesis

Answer

DNA replication

Question 26

Which of the following is NOT a product of amino acid catabolism?

Accepted Answer

Glycogen

Answer

Urea

Answer

Glucose

Answer

Ketone bodies

Question 27

A patient is experiencing a severe deficiency in protein intake. What would you expect to be the primary metabolic response?

Accepted Answer

Increased protein breakdown and gluconeogenesis

Answer

Increased fat storage

Answer

Increased synthesis of non-essential amino acids

Answer

Decreased energy expenditure