Digestion and synthesis
Food contains natural polymers which are broken down during digestion. The breakdown products are then used by the body to make new polymers, during a process called synthesis.
During digestion natural polymers are broken down into nore soluble compounds, for example starch is broken down into glucose and proteins are broken down into amino acids, these are than absorbed in the blood and transported around the body.
Cells grow by building up amino acids from the blood into new proteins, the following body parts are made mostly of proteins:
- Heamoglobins (in blood)
Excess amino acids are broken down in the liver to form urea, this is then excreted by the kidneys in urine.