Digestion Flashcards
What is digestion?
The food we eat has to be broken down into other substances that our bodies can use. This is called digestion.
Where does digestion happen?
Digestion happens in the digestive system, which begins at the mouth and ends at the anus.
Which organs does our food go through?
In order:
- Oesophagus or gullet.
- Stomach.
- Small intestine.
- Large intestine.
Events that occurs during digestion?
- Food is digested in the mouth, stomach and small intestine.
- Digested food is absorbed into the bloodstream in the small intestine.
- Excess water in absorbed back into the body in the large intestine.
- Any undigested food passes out of the anus.
What does the liver produce and how does it help with digestion?
The liver produces bile, which helps the digestion of lipids (fats and oils).
What does the pancreas produce and how does it help with digestion?
The pancreas produces biological catalysts called digestive enzymes, which speed up the digestive reactions.
What is the digestive system?
The digestive system is the organ system that breaks food down into small molecules that are absorbed into the bloodstream. Digestion is help by enzymes, which are biological catalysts.
How do teeth help with digestion?
Our teeth break food down into small pieces when we chew. This is only a start to the process of digestion, as chewed pieces of food are still too large to be absorbed by the body.
Where are Carbohydrates digested?
They are digested in the mouth, stomach and small intestine. Carbohydrate enzymes break down starch into sugars.
How does our saliva help in digestion?
The saliva in your mouth contains amylase, which is another starch digesting enzyme. If you chew a piece of break for long enough, the starch it contains is digested to sugar, and it begins to taste sweet.
Where are proteins digested?
Proteins are digested in the stomach and small intestine. Protease enzymes break down proteins into amino acids. Digestion of proteins in the stomach is helped by stomach acid, which is strong hydrochloric acid. This also kills harmful micro-organisms that may be in the food.
How are liquids digested?
Lipase enzymes break down the fat into fatty acids and glycerol. Digestion of fat in the small intestine is helped by bile, made in the liver. Bile breaks the fat into small droplets that are easier for the lipase enzymes to work on. Bile is not an enzyme.
What happens to the substances which are not digested?
Minerals, vitamins and water are already small enough to be absorbed by the body without being broken down, so they are not digested. Digestive enzymes cannot break down dietary fibre, which is why the body cannot absorb it.
What are the processes that happen in the digestive system?
Ingestion (eating) → digestion (breaking down) → absorption → egestion (removal from the body).
Where is digested food absorbed?
Digested food molecules are absorbed in the small intestine. This means that they pass through the wall of small intestine and into our bloodstream. Once there, the digested food molecules are carried around the body to where they are needed.
Only small, soluble substances can pass across the wall of the small intestine. Large insoluble substances cannot pass through.
