glycolytic pathway

Question 1

what is Embden-Meyerhof pathway (EM) ?

Answer 1

D-(+)-glucose + 2NAD+ + 2ADP + 2Pi
→ 2 pyruvate + 2NADH + 2ATP + 4H+

Question 1

what is Entner-Doudoroff pathway (ED)?

Answer 1

D-(+)-glucose + NADP+ + NAD+ + ADP + Pi → 2 pyruvate + NADH + NADPH + ATP + 2H+

Question 2

what is oxidative pentose phosphate pathway (PP)?

Answer 2

D-glucose 6-phosphate + 2NADP+
→ 2 D-fructose 6-phosphate + glyceraldehyde 3-phosphate + 2NADPH + CO2 + H+

Question 3

cellular central metabolism in the Eukarya?

Answer 3

1. EM glycolysis oxidises D-(+)- glucose pyruvate in cytosol = generating ATP and NADH
2. pyruvate trafficked to mitochondria and transported into matrix
3. link reaction oxidises pyruvate into acetyl CoA and CO2
4. NADH and QH2 enters respiratory chain
5. ATP and GTP are exported from cytosol

Question 4

what is EM glycolysis - cytosolic?

Answer 4

• D-(+)-glucose (6C) → 2pyruvate (2 × 3C)

Question 5

what is link reaction - mitochondrial?

Answer 5

pyruvate (3C) → acetyl-CoA (2C) + CO2
(1C)
pyruvate (3C) → acetyl-CoA (2C) + CO2
(1C)

Question 6

what is krebs cycle - mitochondrial?

Answer 6

acetyl-CoA (2C) → 2CO2 (2 × 1C)
acetyl-CoA (2C) → 2CO2 (2 × 1C)

Question 7

what is the strategy of the EM glycolytic pathway?

Answer 7

• generate electrons and capture them as NADH
• add phosphate groups to C skeletons then convert into metabolites that can donate these phosphate groups to phosphate carriers

Question 8

what are phosphate groups?

Answer 8

• organic metabolites with phosphate groups can be hydrolysed to release them

Question 9

examples of phosphate groups?

Answer 9

1. phosphoenolpyruvate + H2O → pyruvate + Pi
2. ATP + H2O → ADP + P
3. D-glucose 6-phosphate + H2O → D-(+)-glucose + Pi

Question 10

what are phosphoester linkage hydrolyisis?

Answer 10

• some phosphoester bonds hydrolyse hydrolyse more easily than other = this is a characteristic of electronegativity and dipoles in bonds.
• bonds are not high energy