Section 2 e) Key words

Absorption: When digested nutrients are absorbed from the digestive tract into the blood stream, lymphatic system, etc. through the villi.

Amylase: An enzyme that specifically targets starch and glycogen to turn it into simple sugars.

Assimilation: When nutrients absorbed by the body become part of it (used by cells, stored, etc.)

Bile: A substance created in the liver, stored in the gall bladder and released into the duodenum that neutralises the stomach contents and emulsifies lipids.

Bolus: A ball of food that is coated in saliva to make it easy to swallow

Carbohydrase: A group of enzymes that break down carbohydrates into simple sugars.

Carbohydrate: An organic compound made of carbon, hydrogen and oxygen that can be broken down into simple sugars. e.g. starch, glycogen, cellulose and sugar.

Digestion: The process of breaking down food into nutrients through the digestive system. 

Egestion: The removal of undigested and waste materials from the digestive tract.

Enzyme: A biological molecule made of amino acids that has an active site which allows it to speed up chemical reactions in the body. 

Ingestion: Taking food into the body, eating.

Lacteal: A lymph vessel found in villi. Absorbs fatty acids and glycerol.

Lipase: A group of enzymes that break down lipids into fatty acids and glycerol. 

Micro-villi: Tiny folds on the surface of the villus that increase surface area for diffusion

Oesophagus: The food pipe, where chewed-up food is swallowed. 

Pancreas: An organ that secretes digestive enzymes into the duodenum.

Peristalsis: A process in which food is moved through the digestive tract through the relaxation and contraction of circular and longitudinal muscles, creating wave-like movements that push the food forward.

Photosynthesis: The process by which plants turn carbon dioxide, sunlight and water into glucose and oxygen. This is done in the chloroplasts of the cell, where chlorophyll is contained.

Protease: A group of enzymes that break down proteins into amino acids.

Villi: Structures found in the wall of the small intestine. They are hair-like folds that increase surface area for absorption.