Human Nutrition - Flashcards

Vocabulary flashcards about the human digestive system.

Mechanical Digestion (Mouth)

The breakdown of large food pieces into smaller pieces through chewing.

Chemical Digestion

The breakdown of large molecules into smaller molecules using enzymes.

Enzymes in the Digestive System

Chemicals produced by the body to help break down large macromolecules into smaller units.

Amylase

Enzyme that breaks starch down into maltose.

Protease

Enzyme that breaks protein down into amino acids.

Lipase

Enzyme that breaks fats down into fatty acids and glycerol.

Mouth (Digestion)

Where food is chewed into smaller pieces (increasing surface area) and mixed with saliva containing amylase.

Saliva Amylase

Enzyme in saliva that catalyses the digestion of starch to maltose.

Oesophagus

The 'food pipe' that carries food from the mouth to the stomach.

Bolus of Food

A mouthful of food that is swallowed.

Peristalsis

The process where muscles before the bolus contract to force it down, and muscles after it relax to let it pass through the digestive tract.

Gut

The whole of the digestive tract, from the mouth to the anus.

Stomach

Organ where Hydrochloric acid creates acidic conditions, optimum pH for pepsin; acid kills bacteria; muscular contractions mix food with gastric juices; produces chyme.

Chyme

The liquid in the stomach after food mixes with gastric juices.

Pancreatic Juices

Secreted from the pancreas, contains lipase, pancreatic amylase, and protease; neutralizes the acid.

Bile

Secreted from the gallbladder (made in the liver), neutralizes acid from the stomach to provide the optimum pH for digestive enzymes.

Lipase (Small Intestine)

Digests lipids into glycerol and fatty acids.

Emulsification (by Bile)

Converts fat into smaller droplets, to increase the surface area for lipase to digest the fat faster

Liver

Organ where bile is made.

Gall Bladder

Organ where bile is stored.

Lipase Concentration

The effect of lipase on fat digestion can be investigated by looking at this factor.

Small Intestine

Organ that is the primary site where products of digestion are absorbed.

Enzyme in the Mouth

Amylase (carbohydrase)

Enzyme in the Stomach

Pepsin (protease)

Enzymes in the Small Intestine

Trypsin (protease), Lipase, and Pancreatic amylase

Villi

Small finger-like projections in the small intestine that increase the surface area for absorption.

Ingestion

The taking in of food into the body.

Digestion

The breaking down of large insoluble molecules in food into smaller soluble molecules.

Absorption

The taking of digested food into the blood.

Egestion

Expelling undigested material from the body via the anus in faeces.

Assimilation

Using the absorbed nutrients and converting it into living tissue.

Salivary Amylase

Enzyme secreted by the salivary glands, that digests starch in the mouth.

Pancreatic Amylase

Enzyme secreted by the pancreas, that digests starch in the small intestine.

Maltase

Completes the digestion of starch, breaking down maltose.

Pepsin

Protease enzyme secreted into the stomach that begins the digestion of proteins.

Hydrochloric Acid (pH 2)

The pH in the stomach which is optimal for pepsin and kills microbes.

Pancreatic Proteases

Protease enzymes secreted by the pancreas into the small intestine that completes the digestion of proteins into amino acids.

Villi for Absorption

Adaptations of the small intestine for absorption

Large Intestine

This is where water is reabsorbed leaving behind the semi-solid undigested waste (faeces)

Rectum

Where semi-solid undigested waste (faeces) is stored