Enzymes structure and function struc.pptx

enzymes and supstrate

1. Enzymes

2. Enzyme Substrate Active site Chemical reactions Rate Activation Inhibition Cofactors and coenzimes Competetive Allosteric

3. Properties of enzymes Enzymes can not initiate reactions themesevels Enzymes are proteins Their name usually end with “ase” and they have a unque three-dimensional configuration Enzymes are synthesised under control DNA They can operate only within narrow range of temperature and pH

4. Enzymes work in a team The surface area of the substrate affects the speed at which a reaction takes place Enzymes reactions are reversibile Enzymes are very specific Enzymatic reactions are very fast

5. Regulation of enzyme activity Enzyme is coded for by a segment of DNA known as a gene The speed of enzyme-driven reactions is influenced by various physical and chemical factors Some ractions are performed by a serious of enzymes The activity can be decreased by some chemicals called inhibitors

6. Factors that affects enzyme Enzyme concentration Substrate concentration Temperature pH Water concentration Activators Inhibitors

7. Enzyme concentration

8. Door-substrate; Enzyme-key

9. Substrate concentration

10. Temperature

11. pH

12. ATP (Adenosine triphosphate)

13. Metabolic reactions Hydrolysis Condensation (Dehydration) Oxidation-Reduction Transphosphorylation and Other Reactions

14. Hydrolysis  usually means the cleavage of chemical bonds by the addition of water. 

15. Condensation (Dehydration): join two moleculeswith loss of a small molecule

16. Phosphorylation: addition of a phosphate to a molecule. Glucose + ATP Glucose-P + ADP ADP + Pi ATP

17. Substrate level Phosphorilation (SLP) Oxidative Phosphorilation Photophosphorilation Chemosyntetic Phosphorylation

18. ATP-has 3 phosphate and its charged ADP-has 2 phosphate and its uncharged Pi-inorganic phosphate ATP synthase-changes ADP and Pi into a charged ADP Phosphorylation-process of adding a phosphate SLP-in cytosol Oxidative-mitochondria Photo-thylakoid membrane chloroplast Chemosyntetic-chemical oxidation

19. Oxidation –reduction reactions -result in transfer one or more electrons from one reactant to another.

20. Nicotinamide adenine dinucleotide NAD +   - is involved in  redox  reactions, carrying  electrons  from one reaction to another. The coenzyme is, therefore, found in two forms in cells: NAD +  is an  oxidizing agent  – it accepts electrons from other molecules and becomes  reduced . NADH - can then be used as a  reducing agent  to donate electrons

21. Flavin adenine dinucleotide T he molecule consists of a riboflavin   (vitamin B 2 ) bound to the phosphate group of an  ADP  molecule FAD is a  redox   cofactor  involved in reactions in  metabolism FAD accepts two electrons and two protons to become FADH2

22. Coenzyme A It is a derivate of vitamine B involved in transport of acetic acid formed by degradation of proteins, lipids and carbohydrates The combination of acetic acid and coenzyme Aforms the molecule acetyl coenzyme A or CoA

23. Other metabolic reactions Transamination   - transfer of an amine group from one molecule to another

24. Transmethylation -   methyl group  is transferred from one compound to another.

25. Transpeptidation- A reaction involving the transfer of one or more amino acids from one peptide chain to another .

26. Transacetylation -transfer acetyl group of acetate or succinate from one molecule to another. Carboxylation and Decarboxylation- attachment of molecule CO2 to an organic molecule Detoxification - elimination of toxic material from the body.