Chemical Digestion of Foods

These flashcards cover key concepts related to the chemical digestion of foods, focusing on the roles of enzymes, processes, and specific digestive mechanisms.

What is chemical digestion?

The process of breaking down large food molecules into smaller molecules that can be absorbed, primarily using enzymes.

What are the two main ways food is broken down in the body?

Mechanical digestion and chemical digestion.

What is the role of amylase in digestion?

Amylase breaks down starch into simpler sugars like maltose.

What is pepsin, and what does it do?

Pepsin is a protein-digesting enzyme that breaks down proteins into peptides.

Why are enzymes considered biological catalysts?

Enzymes speed up chemical reactions without being consumed in the process.

What is the optimal temperature for human digestive enzymes?

Around 37°C.

What pH does pepsin optimally function in?

An acidic pH of around 2.0.

What is the importance of bile salts in lipid digestion?

Bile salts act as emulsifiers, increasing the surface area of fats for lipid-digesting enzymes (lipases) to act upon.

How does the pancreas contribute to protein digestion in the small intestine?

The pancreas secretes inactive enzyme precursors called zymogens, which are activated in the small intestine to digest proteins.

What is the role of bicarbonate in the digestive process?

Bicarbonate neutralizes the acidic chyme entering the small intestine, creating optimal conditions for pancreatic enzymes to function.

What do brush-border enzymes do in carbohydrate digestion?

Brush-border enzymes break down specific disaccharides into absorbable monosaccharides.

What happens to salivary amylase when food reaches the stomach?

Salivary amylase is inactivated by the acidic pH in the stomach.

What is the sequence of activation for pancreatic zymogens in the small intestine?

Enterokinase activates trypsinogen to trypsin, which then activates other zymogens like chymotrypsinogen and procarboxypeptidase.

What is emulsification, and why is it important for fat digestion?

Emulsification breaks down large fat droplets to increase the surface area for lipases to act upon, facilitating fat digestion.

What detrimental effect can fatty acids have on the intestinal pH?

Fatty acids can lower the pH of the chyme in the small intestine, making it more acidic.

What is the main form of dietary fat that lipases act on?

Triglycerides.

What is the function of lipases in digestion?

Lipases are enzymes that break down triglycerides into fatty acids and glycerol.

How are amino acids absorbed in the small intestine?

Amino acids are absorbed through the intestinal walls into the bloodstream, primarily via active transport and facilitated diffusion.

What role does the liver play in digestion?

The liver produces bile, which is essential for the digestion and absorption of fats.

What is the significance of the small intestine in digestion?

The small intestine is the primary site for digestion and absorption of nutrients.

What factors can affect enzyme activity in digestion?

Enzyme activity can be affected by temperature, pH level, and substrate concentration.

What are zymogens, and why are they important?

Zymogens are inactive enzyme precursors that need to be activated; they prevent the premature digestion of proteins within the pancreas.

What is the primary function of the large intestine during digestion?

The primary function of the large intestine is to absorb water and electrolytes from indigestible food matter and to store waste.

How does the presence of food in the stomach affect enzyme secretion?

The presence of food stimulates the secretion of gastric juices, which contain digestive enzymes and acid.

What is the role of secretin in digestion?

Secretin is a hormone that stimulates the pancreas to release bicarbonate and helps regulate pH in the small intestine.

How do villi and microvilli function in the small intestine?

Villi and microvilli increase the surface area of the small intestine, enhancing nutrient absorption.