Biology Flashcards
Mouth
Teeth break food down into small pieces. Broken up food is mixed with enzymes in your saliva. The enzymes start to break down carbohydrates into sugar.
Oesophagus
The oesophagus is a thin tube connecting the mouth and stomach. Chewed up food is called a bolus - this passes down the oesophagus. Saliva softens the bolus.
Stomach
A stomach is about the size of a fist, but can expand to several times this size. It churns to mix food with stomach acid, which kills unwanted bacteria. The food mixes with enzymes that break down protein into amino acids.
small intestine
The small intestine is around 6 meters long. Fats are digested into fatty acids and glycerol, and the breakdown of carbohydrates and proteins continues. The intestine is covered with villi which help absorb nutrients quickly.
large intestine
The large intestine is wider than the small intestine and about 1.5 meters long. Water is absorbed from digested food, leaving undigestible fibre which is excreted.
Rectum
The undigested fibre is stored as faeces.
Anus
This is a muscular ring acting as the opening at the end of the digestive system. Faeces leaves your body.
What is digestion?
Digestion is the process of when food molecules are broken down into smaller particles using enzymes.
What is absorption?
Absorption is when digested food molecules pass through the wall of the small intestine to be absorbed into our bloodstream.
What is an enzyme?
An enzyme is a biological catalyst which breaks down large molecules into smaller ones.
What are the three main types of enzymes involved in digestion?
Carbohydrase, lipase and protease
What is Carbohydrase (amylase) broken down into?
The carbohydrase is broken down into glucose.
What is preotease broken down into?
Amino Acids
What is Lipase broken down into?
fatty acids and glycerol.
What is Villi?
Villi are tiny finger-like projections made up of cells that line the entire length of your small intestine.
