Gluconeogenesis Pathway: Overview, Enzymes, Co-Factors and Precursors

The video tutorial explains gluconeogenesis, the process of synthesizing glucose from non-carbohydrate precursors, crucial during fasting and starvation. It occurs mainly in the liver and kidneys. The tutorial compares gluconeogenesis with glycolysis, highlighting key enzymes and steps, including pyruvate carboxylase and PEP carboxykinase. It discusses the energy requirements, noting that gluconeogenesis consumes six ATP molecules. The regulation of the pathway by hormones like glucagon and the role of precursors such as lactate, amino acids, and glycerol are also covered.

What is the primary function of gluconeogenesis during fasting?

• To store excess glucose

• To maintain blood glucose levels

• To break down proteins

• To produce ketone bodies

Where does gluconeogenesis primarily occur?

• In the brain

• In the liver

• In the muscles

• In the pancreas

Which enzyme is involved in the irreversible step of converting glucose to glucose 6-phosphate in glycolysis?

• Pyruvate kinase

• Hexokinase

• Phosphofructokinase

• Glucose-6-phosphatase

What is the role of pyruvate carboxylase in gluconeogenesis?

• Converts pyruvate to oxaloacetate

• Converts oxaloacetate to malate

• Converts glucose to pyruvate

• Converts fructose to glucose

Which cofactor is required by malate dehydrogenase during the conversion of oxaloacetate to malate?

• FADH2

• NADH

• GTP

• ATP

How many ATP molecules are consumed in the gluconeogenesis pathway from pyruvate to fructose 1,6-bisphosphate?

• 2 ATP

• 4 ATP

• 8 ATP

• 6 ATP

Which enzyme converts fructose 1,6-bisphosphate to fructose 6-phosphate in gluconeogenesis?

• Phosphofructokinase

• Fructose bisphosphatase

• Hexokinase

• Glucose-6-phosphatase

Which of the following is a gluconeogenic precursor derived from triglyceride metabolism?

• Lactate

• Glycerol

• Alanine

• Aspartate

Which amino acid can be directly converted into pyruvate for gluconeogenesis?

• Valine

• Leucine

• Glutamine

• Alanine

What is the role of lactate in gluconeogenesis?

• It is converted to acetyl-CoA in the brain

• It is converted to oxaloacetate in the kidney

• It is converted to pyruvate in the liver

• It is converted to glucose in the muscles