GLYCOLYSIS AND PYRUVATE OXIDATION

Question 1

WHAT IS glycolysis

Answer 1

it is apart of a metabolic pathway that breaks glucose down to TWO MOLECULES of pyruvate.
- occurs in the cytoplasm and doesnt require oxygen.
there are TEN reactions in the glycolysis pathway
- the first five require energy investment
the last five are energy yielding

Question 2

net reaction for glycolysis?

Answer 2

Glucose + 2NAD+ + 2ADP + 2Pi → 2 Pyruvate + 2H2O + 2NADH + 2ATP

Question 3

phase 1- energy investment step 1

Answer 3

1. glucose is phosphorylated by atp to form
   GLUCOSE 6 PHOSPHATE (G6P).
   an atp molecule is broken down to adp and inorganic phospate and attaches the phosphate to glucose.
   by doing so, it traps the glucose in the cell.
   it also destablizes glucose molecule. the purpose of this prepares it for the breakdown into two pyruvate.

Question 4

phase 1 - energy investment step 2

Answer 4

step 2. glucose 6 phosphate (G6P) is rearranged and its isomere is now fructose 6 phosphate (F6P) as it becomes accessable.

Question 5

phase 1 - energy investment step 3

Answer 5

fructose 6 phosphate is phosphorylated by another atp to become fructose 1,6 biphosphate (F1,6BP). this prepares the molecule for the formation of three carbon sugar phosphates. (similar to step 1)
2 atp is used at this point.

Question 6

phase 2 sugar splits - step 4 and 5

Answer 6

4. the six carbon sugars is cleaved/cut into 2 3 carbon sugars
   1 becomes G3P (GLYCERALDEHYDE 3 PHOSPHATE) and 3 phosphate is good to go.
   the second becomes DHAP (dihydroxyacetone phosphate) which will isomer to G3P IN STEP 5

Question 7

phase 3 - energy yielding step 6

Answer 7

6. the two molecules of g3p are oxidized and two NAD+ are reduced to NADH. both G3P are phosphorylated by one inorganic phosphate each to produce two molecules of 1,3 biphosphoglycerate (BPG)

Question 8

phase 3 - energy yielding step 7

Answer 8

one phosphate is removed from each BPG to produce 2 molecules of 3- phosphoglycerate (3PG)
the phosphates are addeded to adp to produce 2ATP molecules by substrate level phosphorylation

Question 9

phase 3 - energy yielding step 8

Answer 9

8. the remaining phosphate in 3PG is removed from carbon 3 to carbon 2 to form 2-phosphoglyercate (2PG).

Question 10

phase 3 - energy yielding step 9 (wont be asked about it)

Answer 10

9.water is removed from 2PG to produce PEP

Question 11

phase 3 - energy yielding step 10

Answer 11

the last phosphate group is transferred to ADP by substrate level phosphorylation which then produces 2 molecules of pyruvate and 2 atp molecules.

Question 12

summary

Answer 12

Glucose + 2NAD+ + 2ADP + 2Pi → 2 Pyruvate + 2H2O + 2NADH + 2ATP

Question 13

pyruvate oxidation

Answer 13

when oxygen is available, the 2 pyruvate molecules produced during glycolysis are transported from the cytosol into the mitochondrial matrix.

Question 14

3 things happen

Answer 14

co2 is removed (decarboxylation)
NAD + IS REDUCED TO NADH
coenzyme a attaches to the moelcule sugar
pyruvate now becomes aceytl coenzyme a

Question 15

remember how to draw mitochondria

Answer 15

do the worksheet and pg 124 # 12