Lecture 1 Pt 2

Question 1

What does GAPDH do?

Answer 1

Leads to the reduction of NAD+ to NADH.

Question 2

Glucokinase is activated

Answer 2

at high levels of glucose

Question 3

GAP is oxidized/reduced

Answer 3

oxidized

Question 4

NAD+ is oxidized/reduced

Answer 4

i

Question 5

what are the 3 ways NADH, H is regenerated to NAD+

Answer 5

1. Alcoholic fermentation
2. Lactic fermentation
3. Aerobic respiration (long, yields the most energy)

Question 6

What is fermentation

Answer 6

ATP generating pathways in which electrons are removed from one organic compound and passed to another organic compound. Fermentation can take place in the absence of O2

Question 7

how is NAD+ regenerated through lactic fermentation?

Answer 7

Pyruvate (lactic dehydrogenase and reproduces NADH), then produces 2ATP, 2 lactate

Question 8

how is NAD+ regenerated through alcohol fermentation?

Answer 8

Pyruvate (pyruvate decarboxylase -> produce Co2) -> acetaldyhye -> (alcohol dehydrogenase -> regenerate NAD+) -> ethanol

Question 9

Does alchol fermentation occur in humans?

Answer 9

No bc pyruvate carboxylase is not present in animal, requires thiamine

Question 10

Where/what species does Lactic acid fermentation occur?

Answer 10

In muscles: lactice acid

microbes
soy sauce, cheese, youghrt

Question 11

Where/what species does Alchocol fermentation occur?

Answer 11

yeast other microbes

bread beer wine

Question 12

When can lactic acid build up?

Relate this to the glycolysis process

Answer 12

Skeletals, muscles, can only function anaerobically for a short period of time, which builds up lactate, lowers the pH and affects the PFK activity

Question 13

Explain the Warburg effect

Answer 13

Cancer cells have increased metabolism.

After glycolysis is carried out, cells can undergo oxidative phosphorylation (which increases a high yield of enerngy), or fermentation (under no oxygen conditions, and provides lower energy).

Cancer cells have an increae uptake of glucose, and prefer going thorugh lactic fermentation (even in conditions where oxygen is present).

Cancer cells have a dependence for glucose higher than regular cells-> target for remediation

Question 14

What kind of diet would you recommend to people wit

Answer 14

keto

Question 15

Imaging question. What is the name of the molecule that can bind to glucose

Answer 15

FDG (a non-metabolasible glucose analog)
looks similar but does not undergo glycolysis.

glucose molecules csan bind to this. -> fluorescence -> acts as a sign to visualize uptake and see where tumors are localized.

Question 16

What does a stronger FDG indicate

Answer 16

Those cells have a high intake of glucose

Question 17

Does FDG undergo glycolysis?

Answer 17

No, it does not undergo full glycolsysi

Question 18

How many carbons does lactose have? What does it break down to?

Answer 18

12. Glucose and Galactose

Question 19

How many carbons does sucrose have? What does it break down to?

Answer 19

12. Glucose and fructose

Question 20

Where does fructose come from?

Answer 20

Table sugar

Question 21

Where does galactose come from

Answer 21

Milk

Question 22

When does galactose enter the cell

Answer 22

at the glucose-6-p

Question 23

When does fructose (adipose enter the cell)

Answer 23

at the fructose-6-P step (so theres still another ATP requiring step after to make fructose-6-P turn into frutose1,6 bisphosphate

Question 24

When does fructose (liver, enter the cell)

Answer 24

at the DHAP <-> GAP step

Question 25

In the liver, how is fructose metabolized?

Answer 25

The liver is a major site for fructose metabolism. Fructose is metabolized by the fructose 1-phosphate pathway

Question 26

In other tissues, how is fructose directly metabolised? How does fructose enter the pathway?

Answer 26

phosphorylzted by hexokinase -> enters as fructose-6-p

Question 27

Does the metabolism of fructose in the liver still require ATP? How many ATP is yielded at the end of the process?

Answer 27

Yes Still requires the same investment of ATP. Cuz to convert fructose -> fructose -1 phosphate Fructose-1-P -> GAP and DHAP. Glyceraldehyde -> glyceraldyde 3 phosphate 2 ATP is still yielded at the end. Glycolysis and fructolysis in the liver = equivalent in energy

Question 28

For fructolysis in the liver. How many steps of glycolysis were bypassed? Were any of those regulatory steps?

Answer 28

2 steps: Glucose -> glucose-6-P (hexokinase) f-6-p -> f-1.6-p (phosphofructose kinase)

Question 29

Some issues for fruclysis

Answer 29

Excess fructose consumption is harmful (its been linked to obesity, fatty liver and the development of type 2 diabetes) because in the liver, the PFK control point is bypassed -> excess. So an excess of Acetyl CoA is synthesized and converted to fats

Question 30

How does galactose enter the pathway?

Answer 30

galactose is converted to galactose-1-P via galactosekinase. Galactose is gonna convert to Glucose-6-P with a galactose glucose interconversion pathway. Enters pathway at glucose as glucose-6-P

Question 31

What regulatory step does galactose bypass?

Answer 31

hexokinase

Question 32

Why are red blood cells suceptible to deficiencies in glycolysis? What is the disease that it causes?

Answer 32

Mutation (reduction in gene), that encodes for pyruvate kinase -> causes a slow flux from phosphoenolpyruvate -> pyruvate. causes hemolytic anemia

Question 33

Why does lactose intolerance occur? What enzyme is lacking? what are the symptoms

Answer 33

Lactose interolent individuals lack the ability to break down lactose into glucose and galactose. lack the enzyme lactase. Therefore gut bacteria in the stomach would break down lactose into CH4 and H2 -> make stomach upset

Question 34

How does galactosemia occur? What enzyme is lacking? what are the symtoms?

Answer 34

Classic galactosemia results if galactose 1-phosphate uridyl transferase activity is deficient. Symptoms include failure to thrive, jaundice,. cataract formation.

Question 35

What happens if glaactose-1_phosphate uridyl transferase activity is low?

Answer 35

its gonna be highly toixc for the body, build up, health problems, metabolise into otehr things.

Question 36

Write the equation for alcohol fermentation

Answer 36

Write the equation for lactice acid fermentation