Chem 109 C. Fall Armen Zakarian Office: Chemistry Bldn 2217

Transcription

1 Chem 109 C Fall 2014 Armen Zakarian ffice: Chemistry Bldn 2217

2 midterms Midterm 1 max 92.5, min 28.5 average 64; stdev 13.8 Midterm 2 max 90, min 15 average 54; stdev 16.3

3 utline o overview of catabolism o AT phosphorylation o Catabolism of fats o Catabolism of carbohydrates o Catabolism of proteins o Citric acid cycle

4 o verview of Catabolism Chapter 25

5 o AT: structure H 2 H H H adenosine triphosphate AT H H H H H H triphosphoric acids H H adenosine H H H H H H H pyrophosphoric acids phosphoric acids H 2 H H adenine H H H D-ribose H H H H H H H H H three phosphoric acids

6 o AT: carrier of chemical energy - - H H - - H 2 H H H 2 H ΔG kj/mol H adenosine triphosphate adenosine diphosphate hydrogen phosphate H H H H H 2 ΔG 13.8 kj/mol H - H H H - - H H - H - - H H H H AT H H H H AD ΔG kj/mol

7 o AT: phosphorylation mechanism H H H H - H - - AT - Ad - - H H H H - - AD - Ad direct substitution at phosphorus (S 2 type) diphosphate (AD) is a good leaving group breaking bond - phosphoanhydride bond

8 o AT: two types of phosphoryl transfer R Ad R Ad AT acyl phosphate AD R Ad R - Ad AT acyl adenylate pyrophosphate

9 o AT: two types of phosphoryl transfer R - - R'SH R SR' - - H acyl phosphate R - Ad R'SH R SR' - - Ad H acyl adenylate AM

10 o AT: two types of phosphoryl transfer overall reaction achieved: AT AD R - R'SH R SR' R - R'SH R H C SR' R SR'

11 o High-Energy character of phophoanhydride bond: Thermodynamic instability of AT in water Chapter H 2 H H H 2 H ΔG kj/mol H adenosine triphosphate adenosine diphosphate hydrogen phosphate - - H H - key reasons: electrostatic repulsion in AT MRE STABLE better solvation of hydrolysis products greater electron delocalization in products

12 o High-Energy character of phophoanhydride bond: Kinetic stability of AT in water Chapter H 2 H H H 2 SLW H ΔG kj/mol H adenosine triphosphate adenosine diphosphate hydrogen phosphate - - H H - hydrolysis reaction takes weeks to complete repulsion with negatively-charged u

13 o High-Energy character of phophoanhydride bond: Kinetic stability of AT in water Chapter 25

14 RACTICE RBLEM 3. Several important biomolecules and the DG values for their hydrolysis are listed here. Which of them hydrolyses with sufficient energy to drive the formation of AT? glycerol-1-phosphate -9.2 kj/mol fructose-6-phosphate kj/mol phosphocreatine kj/mol glucose-6-phosphate kj/mol Canceled in 7 th ed H 2 H H H 2 SLW H ΔG kj/mol H adenosine triphosphate adenosine diphosphate hydrogen phosphate - - H H -

15 o Catabolism of fats: fats fatty acids acetyl-coa Chapter 25 R 1 R 2 3H 2 hydrolysis H H R 1 H H R 2 R 3 H glycerol H R 3 fatty acids butter

16 o Catabolism of fats: glycerol AT, Mg 2 AD AD, Zn 2 ADH, H H H H H H glycerol glycerol kinase H - - glycerol phosphate dehydrogenase - - (R)-glycerol-3-phosphate dihydroxyacetone phosphate dihydroxyacetone phosphate is processed through glycolytic pathway

17 o Catabolism of fats: fatty acids a fatty acid H 3 acetyl-coa

18 o Catabolism of fats: fatty acids a fatty acid H 3 acetyl-coa stage 1: fatty acid

19 o Catabolism of fats: fatty acids a fatty acid H 3 acetyl-coa stage 1: fatty acid stage 2: acetyl-coa (4-step chopping)

20 o Catabolism of fats: fatty acid, stage 1: Chapter 25 CoASH, AT AD, H 4 2- a fatty acid H acyl-coa synthase a a thioester - - acyl phosphate intermediate

21 o Catabolism of fats: acetyl-coa, st 2 (4 steps): FAD FADH 2 H 2 H a a thioester STE 1 STE 2 an α,β-unsaturated a β-hydroxy AD CoASH STE 3 ADH, H STE 4 a shorter acetyl-coa a β-keto

22 o Catabolism of fats: acetyl-coa, st 2 (4 steps): FAD FADH 2 H 2 H a a thioester STE 1 STE 2 an α,β-unsaturated a β-hydroxy AD CoASH STE 3 ADH, H STE 4 a shorter acetyl-coa a β-keto

23 o Catabolism of fats: acetyl-coa, st 2 (4 steps): FAD FADH 2 H 2 H a a thioester STE 1 STE 2 an α,β-unsaturated a β-hydroxy AD CoASH STE 3 ADH, H STE 4 a shorter acetyl-coa a β-keto

24 o Catabolism of fats: acetyl-coa, st 2 (4 steps): FAD FADH 2 H 2 H a a thioester STE 1 STE 2 an α,β-unsaturated a β-hydroxy AD CoASH STE 3 ADH, H STE 4 a shorter acetyl-coa a β-keto

25 o Catabolism of fats: acetyl-coa, st 2 (4 steps): FAD FADH 2 H 2 H a a thioester STE 1 STE 2 an α,β-unsaturated a β-hydroxy AD CoASH STE 3 ADH, H STE 4 a shorter acetyl-coa a β-keto

26 o Catabolism of fats: acetyl-coa, st 2 (4 steps): FAD FADH 2 H 2 H a a thioester STE 1 STE 2 an α,β-unsaturated a β-hydroxy AD CoASH STE 3 ADH, H STE 4 a shorter acetyl-coa a β-keto

27 o Catabolism of carbohydrates Chapter 25

28 Chapter 24: expectations What will be provided: Substrates and coenzymes - structure What is not necessary for the test: names of diseases associated with vitamin deficiencies

29 Chapter 24: expectations What is expected: Mechanism of reactions Types of reactions (carboxylation, amine transfer, etc.) what enzyme is involved what coenzyme is required from what vitamins are the coenzymes derived ames of relevant enzymes

30 Chapter 24: expectations RACTICE RBLEM 25. For each of the following reactions, name the enzyme that catalyzes the reaction and name the required coenzyme enzyme AT, Mg 2, HC 3 - acetyl-coa -

31 Chapter 24: expectations RACTICE RBLEM rovide a mechanism for the following carboxylation reaction: enzyme AT, Mg 2, HC 3 - biotin - biotin: H H S HE H 2 AT: H H

32 Chapter 24: expectations RACTICE RBLEM 25. For each of the following reactions, name the enzyme that catalyzes the reaction and name the required coenzyme enzyme AT, Mg 2, HC HS SH - enzyme S S - - C enzyme - C - - H enzyme H 3 aspartate enzyme -