GLYCOLYSIS

Question 1

Occurs in

Answer 1

Cytoplasm

Question 2

Converts glucose to

Answer 2

Pyruvate (3 carbons)

Question 3

¿What does generate?

Answer 3

Generates ATP and NADH

Question 4

NADH (nicotinamide adenine dinucleotide)

Answer 4

• Donate electrons transport chain in the mitochondria –> ATP

Question 5

The majority of the reactions are

Answer 5

reversible

Question 6

Not reversible reactions

Answer 6

• Glucose to glucose-6-phosphate
• Fructosa-6-phosphate to fructose-1,6-bidiphosphate
  -Phosphoenolpyruvate to pyruvate

Question 7

Priming stage

Answer 7

• the cell invests energy and spends ATP

Question 8

Splitting stage

Answer 8

• it divides from 6 carbon structure to 3

Question 9

Energy stage

Answer 9

• ATP is generate

Question 10

Hexokinase

Answer 10

• add phosphate groups and most of the time phosphate group will come from ATP
• most tissues
• inhibited by G6P
• Insulin has not effect
• Low Km
• Low Vm

Question 11

Glucose-6-phosphate

Answer 11

• trapped inside of cells

Question 12

Glucokinase

Answer 12

• liver and pancreas
• not inhibited by G6F
• Induced by insulin
• high Km and Vm (rate varies with glucose)
• sigmoidal curve

Question 13

Glucokinase is inactivate when

Answer 13

1- low glucose
2- high F6P (overcome by elevate glucose)

Question 14

GKRP (glucokinase regulatory protein)

Answer 14

• Translocate glucokinase to the nucleus
• Inactivate glucokinase
• Glucose compete with it

Question 15

Low blood sugar (hexo/gluco kinase activity)

Answer 15

• Hexokinase working
• Glucokinase inactive
• Glucose to tissue, not liver

Question 16

High blood sugar (hexo/gluco kinase activity)

Answer 16

• Hexokinase inactive (inhibited by G6P)
• Glucokinase working
• Liver will store glucose as glycogen

Question 17

Glucokinase Deficiency

Answer 17

• Results in mild hyperglycemia
• Pancreas less sensitive to glucose
• exacerbated by pregnancy (gestational diabetes)

Question 18

Phosphofructokinase-1

Answer 18

• Rate limiting step
• Consumed the 2nd ATP

Question 19

Regulation of glycolysis (Phosphofructokinase-1)

Answer 19

• Key inhibitors (less glycolysis: citrate and ATP)
• Key inducers (more glycolysis: AMP, F2,6BP –> insulin and glucagon)

Question 20

How Fructose 2,6 bisphosphate regulates glycolysis

Answer 20

on/off switch of glycolysis
when increases favors glycolysis
when decreases favors gluconeogenesis

Question 21

Glucagon

Answer 21

• Phosphorilate favors gluconeogenesis

Question 22

Insulin

Answer 22

• Dephosphorilate favors glucolisis

Question 23

Splitting stage

Answer 23

-F1,6-P to two molecules GAP
- Reversible for gluconeogenesis

Question 24

Energy stage

Answer 24

• Starts with GAP
• Two ATP per GAP
• Total per glucose = 4
• 2 ATP net
• Pyruvate kinase
• Inhibited by ATP, alanine
• Activated by F1,6BP (feed forward activation)

Question 25

Glucagon and epinephrine

Answer 25

- Inactivation of pyruvate kinase - Slow glycolysis/favors gluconeogenesis

Question 26

Alanine cycle (ALT)

Answer 26

Inhibits of glycolysis

Question 27

Pyruvate can be converted into

Answer 27

1- Actil-CoA (TCA cycle) 2- Lactate (LDH, reversible with NaD+)

Question 28

Plasma elevation of LDH

Answer 28

1- Hemolysis 2- Myocardial infarction 3- Some tumors

Question 29

NAD+ (generated in the convertion of pyruvate to lactate)

Answer 29

- Important in hypoxemia

Question 30

Lactic acidosis

Answer 30

- Increase lactic acid and anion gap acidosis - Decrease pH and HCO3 - Sepsis, bowel ischemia, seizures

Question 31

Muscle cramps

Answer 31

- too much exercise --> too much NAD consumption - favors pyruvate into lactate - pH falls in muscles --> cramps

Question 32

Distance runners have

Answer 32

lots and bigger mitochondria

Question 33

Pyruvate kinase deficiency

Answer 33

- RBC loose glycolisi --> loose ATP - membrane failure --> phagocytosis in spleen - presents in newborns - Splenomegaly

Question 34

2,3 Bisphosphoglycerate (2,3BPG)

Answer 34

- Regulator of oxygen optake - some of them bind to RBC helping them to deliver oxygen - high altitud

Question 35

Energy yield from glucose

Answer 35

-Depends on cell (mitochondria) and oxygen - Oxygen and mitochondria --> glucose+6O2 --> 32 (liver, heart)/30(muscle) - No oxygen or no mithocondria --> glucose--> 2ATP+2Lactate+H2O