Enzymes and Digestion Flashcards
What is the human digestive system composed of?
A long muscular tube and its associated glands
What is the function of glands in the digestive system?
They produce enzymes that hydrolyse large molecules into smaller molecules for absorption
Why is the digestive system considered an exchange surface?
This is because it allows food substances to be absorbed into the body
What is the function of the oesophagus?
It carries food from the mouth to the stomach
What is the function of the stomach?
It is a muscular sac that stores and digests food, especially proteins, using enzymes produced by its inner layer
What is the function of the ileum?
> It is a long muscular tube where food is further digested by enzymes from its walls and digestive glands
It has villi and microvilli to increase surface area for absorption into the bloodstream
What is the function of the large intestine?
It absorbs water, mainly from digestive gland secretions
What is the function of the rectum?
It stores faeces before they are removed via the anus in a process called egestion
What is the function of the salivary glands?
They secrete amylase into the mouth, which hydrolyses starch into maltose
What is the function of the pancreas?
It produces pancreatic juice, which contains:
proteases, which hydrolyses proteins
lipase, which hydrolyses lipids
amylase, which hydrolyses starch into maltose
What are the two stages of digestion?
1/ Physical breakdown - where food is broke into smaller pieces by teeth and stomach churning
2/ Chemical digestion - where enzymes hydrolyse large molecules into smaller, soluble ones
Why is physical breakdown important in digestion?
It makes food easier to ingest and increases the surface area for enzyme action
What is chemical digestion?
The process where enzymes hydrolyse large, insoluble molecules into smaller, soluble ones
What is hydrolysis in digestion?
The splitting of molecules by adding water to break chemical bonds
Why are multiple enzymes often needed to digest a large molecule?
One enzyme hydrolyses it into sections, then other enzymes hydrolyse these sections into smaller molecules
What do carbohydrases do?
Hydrolyse carbohydrates into monosaccharides
What do lipases do?
Hydrolyses lipids (fats and oils) into glycerol and fatty acids
What do proteases do?
Hydrolyse proteins into amino acids
What are the three different digestive enzymes which hydrolyse carbohydrates, lipids and proteins?
Carbohydrases
Lipases
Proteases
