Carbohydrates and Their Metabolism

Carbohydrates are essential biomolecules composed of carbon, hydrogen, and oxygen. They serve as energy sources and structural components in organisms. Carbohydrates are made of monosaccharides, which can form disaccharides and polysaccharides. Digestion breaks down carbohydrates into simple sugars for absorption. Glucose is central to energy production, undergoing glycolysis and other metabolic pathways. Fructose metabolism differs, bypassing some regulatory steps, which can lead to unchecked fat production.

What is the typical ratio of carbon, hydrogen, and oxygen atoms in carbohydrates?

• 1:1:1

• 2:2:1

• 1:2:1

• 2:1:2

Which of the following is a base unit of carbohydrates?

• Disaccharide

• Oligosaccharide

• Polysaccharide

• Monosaccharide

What type of linkage bonds the monomers in glycogen and starch?

• Beta-linkages

• Gamma-linkages

• Alpha-linkages

• Delta-linkages

Which enzyme is responsible for breaking down starch in the human body?

• Maltase

• Amylase

• Sucrase

• Lactase

What is the primary role of dietary fibers in the human diet?

• Supply energy

• Slow digestion and add bulk to stool

• Increase blood glucose levels

• Enhance protein absorption

What is the first step in the energy production from glucose?

• Glycolysis

• Citric acid cycle

• Electron transport chain

• Gluconeogenesis

In the absence of oxygen, what is pyruvate converted into during glycolysis?

• Fructose

• Lactate

• Acetyl-CoA

• Glucose

What process allows the synthesis of new glucose when blood sugar is low?

• Fermentation

• Photosynthesis

• Gluconeogenesis

• Glycolysis

How does fructose metabolism differ from glucose metabolism?

• Fructose is stored as glycogen

• Fructose is regulated by insulin

• Fructose bypasses several regulatory steps

• Fructose is converted directly to glucose

What happens to acetyl-CoA when it is present in excess?

• It is stored as glycogen

• It is converted into fatty acids

• It is converted into glucose

• It is used in glycolysis