GI_Lect26_digestion

What is the primary function of bile in the gastrointestinal tract?

The primary function of bile is to emulsify fats, increasing the surface area for digestion.

What stimulates the liver to produce more bile?

The strongest stimulus for liver bile production is bile returning to the liver.

What is secretin and where is it released from?

Secretin is a hormone released from duodenal enteroendocrine cells in response to acidic chyme.

Which enzyme is responsible for digesting starch?

Amylase is the enzyme responsible for digesting starch.

What are the main macronutrients found in food?

The main macronutrients are carbohydrates, proteins, and lipids (fats).

What is the role of digestive enzymes in chemical digestion?

Digestive enzymes break down macromolecules into smaller molecules that can be absorbed.

Where does chemical digestion of carbohydrates primarily occur?

Chemical digestion of carbohydrates primarily occurs in the mouth and small intestine.

What types of nutrients can the gastrointestinal tract absorb?

The gastrointestinal tract can absorb carbohydrates as monosaccharides, proteins as amino acids, and lipids as free fatty acids and monoglycerides.

What process is needed to make lipids digestible in the gastrointestinal tract?

Emulsification is needed to make lipids digestible.

What are micelles and their role in lipid digestion?

Micelles are small droplets that contain products of fat digestion, helping to keep them soluble and facilitating absorption.

Which enzyme initiates protein digestion in the stomach?

Pepsin initiates protein digestion in the stomach.

What is the difference between luminal and contact digestion?

Luminal digestion occurs with secreted enzymes in the GIT lumen, while contact digestion occurs at the brush border of enterocytes.

What is the purpose of bile salts in lipid digestion?

Bile salts stabilize emulsion droplets and increase the surface area for enzymatic action.

What are the essential amino acids that cannot be produced by the body?

There are 8 essential amino acids that cannot be made by the body in adults.

What are the four major stages of lipid digestion?

The four stages are emulsification, hydrolysis, formation of micelles, and absorption.

Which macronutrient is the primary energy source?

Carbohydrates are the primary source of energy.

What is the process of breaking down triglycerides?

Triglycerides are broken down through hydrolysis by lipase and colipase.

What is the function of pancreatic amylase?

Pancreatic amylase continues the digestion of carbohydrates in the small intestine.

What is the fate of large polysaccharides in chemical digestion?

Large polysaccharides are broken down into smaller saccharides during digestion.

What type of charge do bile salts have and why is it important?

Bile salts have a negative charge, which helps stabilize the emulsion droplets in the small intestine.

What type of bonds does amylase break during carbohydrate digestion?

Amylase breaks α-bonds between glucose molecules in starch.

What is the role of colipase in lipid digestion?

Colipase anchors lipase to the surface of emulsion droplets to facilitate the digestion of fats.

How does mechanical digestion aid in chemical digestion?

Mechanical digestion breaks up food into smaller pieces, increasing the surface area for chemical digestion.

What is the pH environment in the stomach during protein digestion?

The stomach environment is very acidic during protein digestion.

What is hydrolysis in the context of fat digestion?

Hydrolysis in fat digestion refers to the process where triglycerides are broken down into free fatty acids and monoglycerides.