Test flashcards 1

What does hydrochloric acid do?

Activates pepsinogen into pepsin, kills bacteria, and creates an acidic environment in the stomach.

Where is hydrochloric acid produced?

Parietal cells in the stomach.

What is pepsinogen?

The inactive form of pepsin that is secreted by chief cells.

What activates pepsinogen?

Hydrochloric acid.

What does pepsin do?

Breaks down proteins into smaller polypeptides.

What is gastric lipase?

 A fat-splitting enzyme that is found in small quantities; action inhibited by low pH

What does mucus in the stomach do?

Protects the stomach lining and provides lubrication.

What is intrinsic factor?

It is required for the absorption of vitamin B12.

What does gastrin do?

Increases the secretion of hydrochloric acid and gastric juice.

How is gastrin regulated?

Inhibited when stomach pH becomes too low as part of a negative feedback mechanism.

What does secretin do?

Stimulates the pancreas to release bicarbonate, which raises the pH in the duodenum.

Where is secretin released from?

Lining of the duodenum.

What triggers secretin release?

When acidic chyme enters the duodenum.

What does CCK do?

Stimulates the pancreas to release digestive enzymes and causes the gallbladder to contract and release bile.

What triggers CCK release?

When fats and proteins enter the small intestine.

What does pancreatic amylase do?

Breaks down starch and glycogen into disaccharides.

What does pancreatic lipase do?

Breaks down triglycerides into fatty acids and monoglycerides.

What does trypsin do?

Digests proteins and is released as inactive trypsinogen

What activates trypsin?

Enterokinase in the small intestine.

What does chymotrypsin do?

Digests proteins and is activated by trypsin.

What does carboxypeptidase do?

Removes amino acid from the ends of a peptide. Comes from pancreas

What do nucleases do?

Digest nucleic acids.

What do bicarbonate ions do?

Neutralize stomach acid and make the environment in the small intestine alkaline.

What do peptidases do?

Breaks down peptides into amino acids.

What does sucrase do?

Breaks down sucrose into simple sugars.

What does maltase do?

Breaks down maltose into glucose.

What does lactase do?

Breaks down lactose into glucose and galactose.

What does intestinal lipase do?

Breaks down fats into fatty acids and glycerol.

What does bile do?

Emulsifies fats and breaks large fat globules into smaller droplets.

Where is bile produced and stored?

Bile is produced in the liver and stored in the gallbladder.

What is a micelle?

A small droplet of fat formed after bile emulsifies fat, allowing digestion and absorption.

What is a chylomicron?

A fat particle formed in intestinal cells that transports lipids through the lymphatic system.