Grade 11: Chapter 10- The digestive system

Macromolecule

A very large molecule that’s made up of smaller molecules linked together

Metabolism

The sum total of all of the chemical reactions that occur in an organism

Essential nutrient

A nutrient that cannot be made by the body and must therefore be obtained from food

Monosaccharide

A simple sugar with three to seven carbon atoms

Disaccharide

A sugar made up of two monosaccharide molecules

Polysaccharide

A large molecule made up of many linked monosaccharides

Glycogen

A polysaccharide made up of glucose units

Lipid

An organic compound that does not dissolve in water such as fat or oil

Amino acid

A building block of protein

Peptide bond

A bond that holds together the amino acids in a protein

Polypeptide

A linear chain of several amino acids linked by peptide bonds

Hydrolysis

A chemical reaction in which water breaks apart macromolecules into smaller molecules

Enzyme

A protein molecule that helps speed up important chemical reactions in the body

Alimentary canal

The tube through which food is processed, beginning at the mouth and ending at the anus; also known as the digestive tract

Mechanical digestion

The physical breakdown of large pieces of food into smaller pieces in the mouth by the action of teeth, beak or other similar structures, and by contractions and churning motions in the stomach

Chemical digestion

The chemical breakdown of nutrient molecules into smaller molecules by enzyme action

Salivary glands

Glands in the mouth that produce saliva to begin the chemical digestion of food

Saliva

A watery secretion in the mouth that begins the digestive process

Esophagus

The muscular tube through which food passes from the mouth to the stomach

Peristalsis

A wave like series of muscular contractions through the esophagus

Gastric juice

A mixture of Hydrochloric acid, salts, enzymes, water, and mucus that is produced by glands in the stomach to help digest food

Chyme

A thick liquid produced in the stomach made of digested food combined with gastric juice

Pepsin

An enzyme in gastric juice that helps break down proteins into polypeptides

Duodenum

A short, wide, U-shaped section of the small intestine into which food passes from the stomach

Villi

Finger-like projections lining the surface of the small intestine that increase the surface area to improve the absorption of nutrients

Jejunum

The portion of the small intestine that immediately follows the duodenum

Ilieum

The portion of the small intestine that immediately follows the jejunum

Bile

A greenish yellow fluid secreted bu the liver that helps break down fat (NOT AN ENZYME)

Peptic ulcer

A sore in the stomach lining or duodenum, most commonly caused by an infection with the bacteria “Helicobacter Pylori”

Inflammatory bowel disease

The general name for a group of diseases that cause inflammation in the intestines

Crohn’s disease

A form of inflammatory disease that can affect any part of the alimentary canal from mouth to anus

Ulcerative colitis

A form of Inflammatory disease that attacks the colon

Hepatitis

Inflammation of the liver, most commonly caused by a virus

Cirrhosis

The irreversible replacement of healthy liver tissue with non-functioning scar tissue; most commonly caused by alcohol abuse or hepatitis

Diabetes

A condition in which the body is unable to use glucose for energy