The Digestive System (Chemical Digestion)

Enzymes that involves in chemical digestion from mouth to intestines. Concise yet comprehensive with good illustrations and visually nice

1. C h e m i c al D i g e st i on

2. The main nutrients the body needs are: Carbohydrates for energy; proteins for growth and repair; fats to store energy; vitamins and minerals to keep the body healthy.

3. Enzymes - are globular proteins that control biological reactions. Digestive enzymes speed up the breakdown (hydrolysis) of food molecules into their ‘building block’ components .

4. Digestive enzymes Digestive enzymes are the chemicals that break large insoluble food molecules into smaller soluble molecules.

5. Starchy foods contain carbohydrates which are made of long chains of identical small sugar molecules. carbohydratemolecule one sugar molecule Carbohydrates are broken down into the smaller sugar molecules to be used by the body for energy.

6. Mouth Salivary Amylase - a digestive enzyme that acts on starch in food, breaking it down into smaller carbohydrate molecules in the form of maltose . Long carbohydrate molecule Simple sugar molecules Amylase

7. Proteins , like carbohydrates, are made of long chains of small molecules. In proteins, these small molecules are not identical. protein molecule one amino acid Proteins are made up of chains of small molecules called amino acids . There are over 20 different kinds of amino acid. Proteins are used by the body for growth and repair .

8. Stomach Protease - a ny enzyme that breaks down protein into its building blocks, the amino acids. T hree main proteases are pepsin, trypsin and chymotrypsin . Long protein molecule Amino acid molecules protease

9. Fats are made up of fat molecules which contain fatty acids and glycerol. fat molecule glycerol Fat molecules have to be broken down by the body so that they can be used for energy storage . fatty acids

10. Small Intestine Lipase - the enzyme responsible in breaking fats into fatty acids and glycerol . Lipase fat molecule glycerol fatty acids

11. Fats are digested in two stages: Firstly, bile (released by the gall bladder) allows the fat to “mix” with water by breaking the fat into smaller droplets. This is called emulsification . Secondly, the digestive enzyme lipase breaks each fat molecule into the smaller glycerol fatty acid molecules . bile Lipase + fat molecule glycerol fatty acids

12. Small Intestine Nuclease - this enzyme play crucial roles in various DNA repair processes, which involve DNA replication, base excision repair, nucleotide excision repair, mismatch repair, and double strand break repair . The end product will be pentoses , phosphates, nitrogenous bases which mainly the chemical structure of our DNA.

13. Enzymes Produces in Site of Release pH level Carbohydrate Digestion: Salivary amylase Pancreatic amylase Maltase Salivary glands Pancreas Small Intestine Mouth Small Intestine Small Intestine Neutral Basic Basic Protein Digestion: Pepsin Trypsin Peptides Gastric glands Pancreas Small Intestine Stomach Small Intestine Small Intestine Acidic Basic Basic Nucleic Acid Digestion: Nuclease Nucleosidases Pancreas Pancreas Small Intestine Small Intestine Basic Basic Fat Digestion: Lipase Pancreas Small Intestine Basic