BIOCHEMISTRY WGU C785 EXAM QUESTIONS
AND ANSWERS
Nonenzymatic glycosylation or glycation creates glycoproteins by:
1. Chemical addition of sugars to polypeptides
2. Extracellular synthesis
3. Attaching 20 amino acids
4. Secretion into extracellular matrix - Correct Answers -1
Nonenzymatic glycosylation or glycation creates glycoproteins by the chemical addition
of sugars to polypeptides. Since this type of glycosylation is nonenzymatic, the time and
the concentration of sugar control glycosylation. Because people with higher circulating
levels of glucose have higher levels of nonenzymatic glycosylation, measurement of the
glycosylated hemoglobin A1c is a diagnostic test used to monitor blood sugar levels in
persons with diabetes.
Which of the following is a 5-carbon sugar?
1. Glucose
2. Fructose
3. Ribose
4. Sucrose - Correct Answers -3
Ribose is a pentose, a simple sugar (monosaccharide) that has five carbon atoms per
molecule. It is synthesized in the body and obtained in small amounts from consumption
of ripe fruits and vegetables. Ribose serves as an energy substrate for the resynthesis
of ATP and is a key component of ribonucleic acid (RNA). Deoxyribose, a component of
DNA, also is a pentose.
The optimum pH of pepsin is:
1. 5
2. 7.1
3. 8.1
4. 2 - Correct Answers -4
The optimum pH for enzymes varies for different enzymes and even enzymes with
similar actions may have different optimal pH based on where they act. For example,
trypsin, a digestive enzyme that acts in the small intestine has an optimal pH of 8 while
pepsin, which acts in the more acidic milieu of the stomach, has an optimal pH of 2.
A proteolytic enzyme has the following action:
1. It cleaves complex sugars into simple sugars.
2. It joins fatty acids into proteins.
AND ANSWERS
Nonenzymatic glycosylation or glycation creates glycoproteins by:
1. Chemical addition of sugars to polypeptides
2. Extracellular synthesis
3. Attaching 20 amino acids
4. Secretion into extracellular matrix - Correct Answers -1
Nonenzymatic glycosylation or glycation creates glycoproteins by the chemical addition
of sugars to polypeptides. Since this type of glycosylation is nonenzymatic, the time and
the concentration of sugar control glycosylation. Because people with higher circulating
levels of glucose have higher levels of nonenzymatic glycosylation, measurement of the
glycosylated hemoglobin A1c is a diagnostic test used to monitor blood sugar levels in
persons with diabetes.
Which of the following is a 5-carbon sugar?
1. Glucose
2. Fructose
3. Ribose
4. Sucrose - Correct Answers -3
Ribose is a pentose, a simple sugar (monosaccharide) that has five carbon atoms per
molecule. It is synthesized in the body and obtained in small amounts from consumption
of ripe fruits and vegetables. Ribose serves as an energy substrate for the resynthesis
of ATP and is a key component of ribonucleic acid (RNA). Deoxyribose, a component of
DNA, also is a pentose.
The optimum pH of pepsin is:
1. 5
2. 7.1
3. 8.1
4. 2 - Correct Answers -4
The optimum pH for enzymes varies for different enzymes and even enzymes with
similar actions may have different optimal pH based on where they act. For example,
trypsin, a digestive enzyme that acts in the small intestine has an optimal pH of 8 while
pepsin, which acts in the more acidic milieu of the stomach, has an optimal pH of 2.
A proteolytic enzyme has the following action:
1. It cleaves complex sugars into simple sugars.
2. It joins fatty acids into proteins.
