1. A Road Map for Cellular Respiration Cytosol Mitochondrion High-energy electrons carried by NADH High-energy electrons carried mainly by NADH Glycolysis Glucose 2 Pyruvic acid Krebs Cycle Electron Transport

2. Fate of Pyruvate

3. 2 Pyruvic acid Overview of Glycolysis

4. Glycolysis: 1

5. Phosphoryl transfer reaction. Kinases transfer phosphate from ATP to an acceptor. Hexokinase has a more general specificity in that it can transfer phosphate to other sugars such as mannose. Phosphate group added to #6 carbon from the ATP ENZYME- Hexo – substrate kin – transfer P b/t substate and ATP/ADP ase - enzyme The name of the molecule phosphate on #6 carbon Step 1- add phosphate to #6 C

6. Isomerization by phosphoglucose isomerase The enzyme opens the ring, catalyzes the isomerization, and promotes the closure of the five member ring. GLUCOSE Aldose sugar An aldehyde with C=O on end C FRUCTOSE ketose sugar A ketone with C=O on a middle C Step 2- glucose  fructose

7. Glucose to fructose - isomerization aldose  ketose Step 2- again Changed the structure – moved the carbonyl (C=O) from #1 C to #2 C. An isomer ENZYME- Hexo – phosphohexose isomer – 6 member ring to 5 member ring ase - enzyme

8. Adding another phosphate The 2 nd investment of an ATP in glycolysis. Step 3- add phosphate to #1 C Name of the molecule Fructose – 5 member ring Phosphate on #1 and # 6 carbons ENZYME- phosphofructo – substate kin – transfer P b/t substate and ATP/ADP ase - enzyme

9. Cleavage to two triose phosphates Enzyme: aldolase C=O on the end – a aldehydye C=O is on the #1 C C=O in middle – a ketone Dihydroxy – two OH (except phosphate in second OH spot Step 4- break 6C into two 3C sugars

10. Cleavage of six-carbon sugar: step 4 again shows where the cut is made and why two different sugars result This one will not go down the pathway – that would be a waste of half the original glucose. STOP!!! This one will go down the pathway – the enzymes are shape specific. GO!!!

11. Salvage of three-carbon fragment ketone  aldehyde Step 5- moving the carbonyl - isomerization

12. Glycolysis: 3

13. Done in two steps – this shows the overall result glyceraldehyde 3-phosphate 1,3 bisphosphoglycerate Step 6- adding another phosphate w/o using ATP!!!! ENZYME- Glyceraldehyde 3-phosphate – substrate dehydrogen – hydrogen removed and replaced by phosphate ase - enzyme Phosphate from cytoplasm

14. Stage 3: The energy yielding phase. Step 6- adding another phosphate w/o using ATP!!!! An aldehyde is oxidized to carboxylic acid and inorganic phosphate is transferred to form acyl-phosphate. NAD + is reduced to NADH. Note, under anaerobic conditions NAD + must be re-supplied. With oxygen and mitochondria, NADH will go down electron transport chain and generate ATP.

15. The two steps. Aldehyde Acid

16. Step 7 Substrate-level phosphorylation Phosphate group moved from the substrate to ADP generating an ATP. Kinase enzyme involved in the change At this point 2ATPs were invested and 2ATPs are produced. Step 7- moving the phosphate group from substrate to ADP

17. Step 8: Phosphate shift setup Step 8- moving the phosphate group from #3 to #2 C ENZYME- phosphoglycerate – substrate mut – changes the structure (sorry not isomerase) ase - enzyme

18. Step 8- moving the phosphate group from #3 to #2 C

19. Generation of second very high energy compound by a dehydration reaction Step 9- forming an enol with a double bond between carbons Dehydration reaction the energy is locked into the high energy unfavorable enol configuration C=C with OH group alkene alcohol

20. An enol phosphate is formed: step 9 Dehydration elevates the transfer potential of the phosphoryl group, which traps the molecule in an unstable enol form Enol: molecule with hydroxyl group next to double bond

21. Step 10: Formation of Pyruvate & ATP ENZYME- pyruvate – substrate kin – phosphate transfer between substrate and ATP/ADP ase - enzyme Step 10- forming pyruvate

24. Diverse fates of pyruvate To citric acid cycle

25. In anaerobic yeast, pyruvate->ethanol Pyruvate is decarboxylated. Acetaldehyde is reduced.

26. ATP