Exam 1 2025

Question 1

What is the function of GLUT1?

Answer 1

Transport glucose at a constant rate

Found in red blood cells and the blood-brain barrier

Question 2

Where is GLUT2 primarily found?

Answer 2

Liver, pancreas, and kidney

Functions in glucose uptake and release, acting as a glucose sensor

Question 3

What is the primary role of GLUT3?

Answer 3

High-affinity transporter for rapid glucose uptake

Predominantly in neurons

Question 4

What type of glucose uptake does GLUT4 facilitate?

Answer 4

Insulin-dependent glucose uptake

Found in adipose tissue and muscle

Question 5

What is the main function of GLUT5?

Answer 5

Transport of fructose

Primarily involved in the small intestine

Question 6

What is the significance of glucose transporters?

Answer 6

Facilitate the passive transport of glucose across the cell membrane

Vary in affinity and capacity, matching the metabolic needs of different tissues

Question 7

What syndrome is caused by GLUT1 deficiency?

Answer 7

GLUT1 Deficiency Syndrome

Leads to seizures, developmental delays, and motor dysfunction

Question 8

What condition is associated with GLUT2 mutation?

Answer 8

Fanconi-Bickel Syndrome

Characterized by glycogen storage issues, hepatomegaly, and renal tubular dysfunction

Question 9

What is linked to GLUT4 impairment?

Answer 9

Insulin resistance and Type 2 Diabetes

Question 10

What is the primary function of the liver in glucose metabolism?

Answer 10

Central in glucose homeostasis, glycogen storage, and gluconeogenesis

Question 11

What role does muscle play in glucose metabolism?

Answer 11

Glucose uptake and utilization for energy during contraction

Question 12

What is the pancreas’s function in glucose regulation?

Answer 12

Sensing blood glucose levels and regulating insulin/glucagon secretion

Question 13

Where does oxidative phosphorylation occur?

Answer 13

Mitochondria

Question 14

What metabolic process occurs in the cytoplasm?

Answer 14

Glycolysis and initial steps of gluconeogenesis

Question 15

What is the first intermediate in glycolysis?

Answer 15

Glucose

Question 16

Which enzyme converts glucose to glucose-6-phosphate?

Answer 16

Hexokinase/Glucokinase

Question 17

What is the enzyme that converts fructose-6-phosphate to fructose-1,6-bisphosphate?

Answer 17

Phosphofructokinase-1

Question 18

What are the two products of aldolase in glycolysis?

Answer 18

Glyceraldehyde-3-phosphate and Dihydroxyacetone phosphate

Question 19

What is generated during glycolysis?

Answer 19

Net 2 ATP and 2 NADH

Question 20

What does gluconeogenesis consume per glucose molecule synthesized?

Answer 20

4 ATP, 2 GTP, and 2 NADH

Question 21

What inhibits hexokinase/glucokinase?

Answer 21

Glucose-6-phosphate

Question 22

What activates phosphofructokinase-1 (PFK-1)?

Answer 22

AMP

Inhibited by ATP and citrate

Question 23

What activates pyruvate kinase?

Answer 23

Fructose-1,6-bisphosphate

Inhibited by ATP and alanine

Question 24

What is the importance of lactic fermentation?

Answer 24

Allows for ATP generation under anaerobic conditions

Question 25

What enzyme reduces pyruvate to lactate?

Answer 25

Lactate dehydrogenase

Question 26

What are the symptoms of Pyruvate Dehydrogenase Deficiency?

Answer 26

Lactic acidosis and neurological symptoms

Question 27

What pathway does galactose metabolism follow?

Answer 27

Galactose → Galactose-1-phosphate → UDP-Galactose → Glucose-1-phosphate

Question 28

What deficiency causes galactosemia?

Answer 28

Deficiency in galactose-1-phosphate uridyltransferase

Question 29

What are the symptoms of galactosemia?

Answer 29

Jaundice, hepatomegaly, and intellectual disability

Question 30

What pathway does fructose metabolism follow?

Answer 30

Fructose → Fructose-1-phosphate → Glyceraldehyde and DHAP

Question 31

What deficiency causes Hereditary Fructose Intolerance?

Answer 31

Deficiency in aldolase B

Question 32

What are the symptoms of Hereditary Fructose Intolerance?

Answer 32

Hypoglycemia, vomiting, and liver damage after fructose ingestion