6.1 Explain Why Digestion Of Large Food Molecules Is Essential

Digestive system

6.1.1 explain why digestion of large food molecules is essential

* Large food molecules are polymers, broken down into monomers in order to be absorbed into the blood * Humans eat substances by other organsims, many which are not suitable for human tissues therefore they must be broken down and reassembled in a form that is suitable * Many molecules in foods are too large to be absorbed by the villi in the small intestine, the large molecules have to be broken down into small molecules that can then be absorbed by diffusion, facilitated diffusion or active transport.

6.1.2 explain the need for enzymes in digestion enzymes speed up the rate of digestion

6.1.3 state the source, substrate, product and
To avoid food poisoning. * Acid conditions denature proteins and suit protein digestion by hydrolysis protease secreted in the stomach ( pepsin) begins the process by breaking up polypeptides into shorter chains of amino acids * The wall of the stomach is elastic ( large meals can be swallowed quickly, stored and then gradually released in the small intestine) * The wall of the stomach is muscular and contracts rthymically to squeeze the food, mixing it and breaking it into smaller lumps
Small intestine * pancreatic juice is secreted into the small intestine containing protease, amlyse and lipase so the three main groups of macromolecules * the wall of the small intestine secretes variety of other enzymes which digest other substances. Nucleases; secreted to digest DNA and RNA in foods. Because of the great length of small intestine, food spends hours passing