Glycolysis (Ben) Flashcards Preview

Y Biochemistry 2 > Glycolysis (Ben) > Flashcards

Flashcards in Glycolysis (Ben) Deck (16)
Loading flashcards...
1

What is the first reaction of glycolysis?

Substrate(s)?

Enzyme?

Product(s)?

Regulation?

Other important things to note?

Substrates: Glucose + ATP

Enzyme: Hexo-/Glucokinase

  • Glucokinase (higher Km) in either liver or pancreatic b-cells as glucose level regulation mechanism

Products: Glucose-6-phosphate + ADP

Regulation: Allosteric via G-6-P

Notes: Irreversible + an important regulatory step

2

What is 2nd reaction of glycolysis... (the one including glucose-6-phosphate as its substrate) ?

Enzyme?

Product(s)?

Other important things to note?

- isomerization of G-6-P via...

Enzyme: Phosphohexose Isomerase

Product: Fructose-6-phosphate

Note: Reversible

3

What is the third reaction of glycolysis, acting upon fructose-6-phosphate?

Substrate(s)?

Enzyme?

Product(s)?

Other important things to note?

Phosphorylation of fructose-6-phosphate using ATP via...

Enzyme: Phosphofructokinase

Product: Fructose 1,6 Bisphosphate + Phosphoric Acid

Notes: 

  • Irreversible + the so-called committed step of glycolysis
  • Inhibited by normal intracellular [ATP]
    • Inhibition relieved by 5'AMP due to ADP buildup

 

4

What is the 4th reaction of glycolysis, resulting in two isomeric products, only one of which continues to be used in glycolysis?

Substrate(s)?

Enzyme?

Product(s)?

Other important things to note?

Substrate: Fructose 1,6-bisphosphate

Enzyme: Aldolase

Products: Dihydroxyacetone Phosphate + Glyceraldehyde-3-Phosphate

Notes: Reversible

5

What is the 6th reaction of glycolysis, acting on glyceraldehyde 3 phosphate?

Substrate(s)?

Enzyme?

Product(s)?

Other important things to note?

Substrates: Glyceraldehyde-3-phosphate + NAD+ + Pi

Enzyme: Glyceraldehyde-3-phosphate dehydrogenase

Products: 1,3-Bisphosphoglycerate + NADH + H+

Note: Reversible

6

What is the fifth reaction of glycolysis, converting a 3 carbon substrate to its isomer?

Substrate(s)?

Enzyme?

Product(s)?

Other important things to note?

Substrate: Dihydroxyacetone Phosphate

Enzyme: Triose Phosphate Isomerase

Product: Glyceraldehyde-3-phosphate

Note: Reversible

7

What is the seventh reaction of glycolysis + its first energetically productive step?

Substrate(s)?

Enzyme?

Product(s)?

Other important things to note?

Substrates: 1,3-Bisphopshoglycerate ADP

Enzyme: Phosphoglycerate Kinase

Products: 3-Phosphoglycerate + ATP

Note: Reversible + an example of substrate level phosphorylation

 

8

What is the 8th reaction of glycolysis, using 3-phosphoglycerate as its substrate?

Enzyme?

Product(s)?

Other important things to note?

Enzyme: Phosphoglycerate Mutase

Product: 2-Phosphoglycerate

Note: Reversible

9

What is the ninth (and second-to-last) reaction of glycolysis?

Substrate(s)?

Enzyme?

Product(s)?

Other important things to note?

Substrate: 2-Phosphoglycerate

Enzyme: Enolase

Product: Phosphoenolpyruvate

Note: Reversible

10

What is the final reaction of glycolysis?

Substrate(s)?

Enzyme?

Product(s)?

Other important things to note?

Substrate: Phosphoenolpyruvate + ADP

Enzyme: Pyruvate Kinase

Product: Pyruvate + ATP

Note: IRREVERSIBLE + an example of substrate level phosphorylation 

21

What is the point of phosphorylation in the 1st step of glycolysis?

Glucose-6-phosphate is not as easily transported out of the cell and this phosphorylation traps glucose in the cell in order for glycolysis to continue.

22

What is the important regulatory molecule formed in some cells by skipping/changing some steps of glycolysis?

What is its role and at what concentration is it found?

 

What enzyme catalyzes this different glycolytic route?

 

 

 

2,3-bisphosphoglycerate

- it binds to deoxy-hemoglobin in RBCs and decreases its O2 binding affinity

- it is found at about 5 mM in RBCs

Bisphosphoglycerate mutase catalyzes the change of 1,3- to 2,3-

23

How does 2,3-bisphosphoglycerate re-enter glycolysis?

Via hydrolysis to 3-phosphoglycerate (and Pi) by the enzyme 2,3-bisphosphoglycerate phosphatase

24

What is the net reaction of glycolysis?

25

What is the pathway for anaerobic processing of pyruvate in humans (as in intense exercise)?

Substrates?

Enzymes/co-enzymes?

Products?

Lactic Acid Fermentation

Substrate: Pyruvate

Enzyme/Co-enzyme: Lactate Dehydrogenase + NADH + H+

Product: Lactate + NAD+

 

26

What is the overall net reaction of anaerobic glycolysis?