* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Key - UCSB CLAS
Light-dependent reactions wikipedia , lookup
Electron transport chain wikipedia , lookup
Fatty acid synthesis wikipedia , lookup
Microbial metabolism wikipedia , lookup
Catalytic triad wikipedia , lookup
Enzyme inhibitor wikipedia , lookup
Radical (chemistry) wikipedia , lookup
Adenosine triphosphate wikipedia , lookup
Multi-state modeling of biomolecules wikipedia , lookup
Photosynthetic reaction centre wikipedia , lookup
Photosynthesis wikipedia , lookup
Metabolic network modelling wikipedia , lookup
Biosynthesis wikipedia , lookup
NADH:ubiquinone oxidoreductase (H+-translocating) wikipedia , lookup
Biochemistry wikipedia , lookup
Citric acid cycle wikipedia , lookup
Amino acid synthesis wikipedia , lookup
Oxidative phosphorylation wikipedia , lookup
Metalloprotein wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Chem 109C - CLAS – Ch 24 - Key 1. What role do cofactors play? Give 2 examples of cofactors. Cofactors are molecules or metal ions that work with enzymes in biochemical reactions – examples include NAD+, FAD, TPP, biotin, PLP, lipoate, and CoASH 2. Niacin is required to make the coenzymes NAD+, NADP+, NADH and NADPH which are necessary for redox reactions on functional groups that contain oxygen. The coenzymes NAD+and NADH are used in catabolic pathways as opposed to the coenzymes NADP+ and NADPH are used in anabolic pathways. 3. Predict the products and provide the mechanisms for the following reactions: a. O O - O O - NAD+ O O - O O OH - O b. O O O - + NH3 O NADPH H+ HO - + NH3 O 4. Vitamin B2 is required to make the coenzymes FAD, FADH2, FMN, and FMNH2 which are necessary for redox reactions in mostly compounds without the element oxygen. 5. Predict the products and provide the mechanism for the first 3 reactions: a. O O - FAD - O O SH S S SH b. O O O FAD - O NH2 - NH c. O O - O - O d. NADH + H+ + FAD FAD O O - O - O NAD+ + FADH2 active site for FAD and FMN 6. The coenzyme TPP is derived from the vitamin B1. TPP is required for decarboxylation and acyl transfer reactions on the substrate pyruvate. 7. Predict the products and provide the mechanism for the following: a. O - TPP O O H+ + H O CO 2 b. O O O - O + - H+ O O OH O + CO 2 TPP O O 8. How many enzymes and coenzymes are involved in the pyruvate dehydrogenase system? O - O O + pyruvate dehydrogenase CoASH system O SCoA + CO 2 3 enzymes and 5 coenzymes – 1) TPP 2) lipoate (enzyme bound) 3) CoASH 4) FAD (enzyme bound) and 5) NAD+ 9. The coenzyme biotin a.k.a. vitamin H is used for carboxylation reactions on alpha carbon substrates. Biotin is accompanied by two other cofactors ATP and Mg2+. Biotin is bound to its enzyme via a(n) amide linkage to a lysine residue. Bicarbonate is the source of carbon dioxide. 10. Predict the product and provide the mechanism: O - O O + HCO 3 - biotin ATP Mg2+ O - O O O - + ADP + HPO 4 2- O 11. The coenzyme PLP a.k.a. vitamin B6 is used for the following 5 reactions: decarboxylation, racemization, transamination, α,β bond cleavage and α,β elimination All of these reactions take place on amino acids. PLP is bound to its enzyme via a(n) imine linkage to a lysine residue. All 5 reactions start with a transamination step in the mechanism. 12. Provide the mechanism for the decarboxylation and transamination of alanine. Decarboxylation overall reaction ⇒ decarboxylation mechanism ⇒ transamination overall reaction ⇒ transamination mechanism ⇒