Question 1

What is chemical digestion?

Accepted Answer

Chemical digestion is the process of breaking down large, insoluble food molecules into small, soluble molecules. This breakdown is achieved through enzymatic hydrolysis. For example, the digestion of starch into glucose.

Question 2

What role does chemical digestion play in nutrient absorption?

Accepted Answer

Chemical digestion produces small, soluble molecules that can be absorbed into the bloodstream. These molecules (e.g., glucose, amino acids) are then transported to cells for various functions. Absorption takes place in the small intestine.

Question 3

What is the function of amylase, and what does it break down?

Accepted Answer

Amylase is an enzyme that breaks down starch into smaller sugars, specifically maltose. This process begins in the mouth with salivary amylase and continues in the small intestine with pancreatic amylase.

Question 4

What is the function of proteases, and what do they break down?

Accepted Answer

Proteases are enzymes that break down proteins into amino acids. Examples include pepsin in the stomach and trypsin in the small intestine, each working under different pH conditions.

Question 5

What is the function of lipase, and what does it break down?

Accepted Answer

Lipase is an enzyme that breaks down fats and oils (lipids) into fatty acids and glycerol. Pancreatic lipase, secreted by the pancreas into the small intestine, is a key example.

Question 6

Where are amylase, protease, and lipase secreted, and where do they act?

Accepted Answer

Amylase is secreted in the mouth and pancreas, acting in the mouth and small intestine. Proteases are secreted in the stomach and pancreas, acting in the stomach and small intestine. Lipase is secreted in the pancreas, acting in the small intestine.

Question 7

What are the two main functions of hydrochloric acid in gastric juice?

Accepted Answer

Hydrochloric acid (HCl) in gastric juice kills harmful microorganisms ingested with food. It also provides an acidic environment (low pH) that is optimal for the activity of pepsin, a protease enzyme.

Question 8

Describe the digestion of starch in the small intestine, including the role of maltase.

Accepted Answer

Amylase breaks down starch into maltose. Maltase, an enzyme located on the epithelial lining of the small intestine, then breaks down maltose into glucose. Glucose is then absorbed into the bloodstream.

Question 9

Describe the roles of pepsin and trypsin in protein digestion.

Accepted Answer

Pepsin, found in the stomach, breaks down proteins into smaller peptides in acidic conditions. Trypsin, secreted by the pancreas into the small intestine, further breaks down these peptides into amino acids in alkaline conditions.

Question 10

What is the function of bile in digestion?

Accepted Answer

Bile is an alkaline mixture produced by the liver and stored in the gall bladder. It neutralizes the acidic chyme entering the duodenum from the stomach, creating a suitable pH for enzymes like pancreatic lipase to function effectively.

Chemical digestion

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