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Flashcards in Week 4 Deck (33)
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1
Q

What is stage one of metabolism?

A

Digestion and hydrolysis

2
Q

What is stage two of metabolism?

A

Degradation and some oxidation to small molecules

3
Q

What is stage three of metabolism?

A

Oxidation to CO2, H2O and energy for ATP

4
Q

How are macronutrients digested?

A

Enzymes throughout the digestive tract break polysaccharides (starch)

5
Q

Identify two ways carbohydrates digested

A
  1. In the mouth, salivary amylase hydrolyses a-glycosidic bonds in polysaccharides to give smaller polysaccharides (dextrins), maltose, some glucose
  2. Insmall intestine: pancreatic amylase hydroglyses dextrins to maltose and glucose
6
Q

What is energy generated by under aerobic conditions?

A

Citric acid cycle and oxidative phosphorylation

7
Q

Where does glycolysis take place?

A

The cytosol of a cell

8
Q

What does glycolysis do?

A

Converts glucose into 2 pyruvates, 2 ATP and 2 NADH

9
Q

What are the two main phases of glycolysis?

A

Energy investment phase

Energy generation phase

10
Q

What is the end result of the Energy Investment Phase?

A

2 ATP molecules have been spent

Glucose (6 carbon) has been degraded into 2x glyceraldehyde-3-phosphate (3 carbons + 1 phosphorus each)

11
Q

What is the end result of the Energy Generation Phase?

A

Glycolysis generates 2 ATP and 2 NADH
2 ATP has been used in energy-investment to add the phosphate groups to glucose and fructose-6-phosphate
4 ATP are formed in energy-generation by direct transfer of phosphate groups to add 4 ADP

12
Q

Where is NADH produced?

A

Cytoplasm

13
Q

What is the role of glycerol-3-phosphate?

A

To transfer hydrogen and electrons into the mitochondria to FAD, which creates FADH2-

14
Q

What do the pathways for glycolysis pyruvate depend on?

A

The availability of oxygen

15
Q

What happens during the oxygen available (aerobic conditions)?

A

Pyruvate will decarboxylate to produce acetyl-CoA and CO2
2 pyruvate are oxidised to 2 acetyl CoA and 2 NADH
2 NADH enters the electron transport to provide 3 ATP each

16
Q

What happens during the oxygen unavailable (anaerobic conditions)?

A

Pyruvate will reduce to lactate which replenishes NAD+, allowing glycolysis to continue with less energy

17
Q

What does fermentation do and where does it occur?

A

Decarboxylates pyruvate to acetaldehyde, which is reduced to ethanol. It occurs in anaerobic microorganisms (yeast)

18
Q

What happens to excessive glucose?

A

It is converted to glycogen for storage in liver

19
Q

What happens when blood sugar levels are too low?

A

There isn’t enough energy to function

20
Q

What happens when blood sugar levels are too high?

A

It can cause nerve damage and elevate blood acidity

21
Q

How is blood sugar levels controlled?

A

Hormones insulin and glucagon are released

22
Q

What is glucose?

A

The primary energy source for the brain, skeletal muscle and red blood cells

23
Q

What can glucose deficiency increase?

A

An impairment to the brain and nervous system

24
Q

What is the role of glycogenesis?

A

It stores glucose by converting glucose to glycogen

25
Q

When does glycogenesis operate?

A

Operates when high levels of glucose-6-phosphate are formed in 1st reaction of glycolysis

26
Q

When doesn’t glycogenesis operate?

A

Doesn’t operate when energy stores (glycogen) are full. This means additional glucose is converted to body fat

27
Q

What is glycogenesis?

A

The breakdown of glycogen to glucose

28
Q

What is glucose synthesis?

A

The synthesis of glucose from carbon atoms of noncarbohydrates compounds

29
Q

When is glycose synthesis required?

A

It is required when glycogen stores are depleted

30
Q

What happens during the Cori Cycle?

A

Lactate moves through the bloodstream to the liver, where it is oxidised back to pyruvate

31
Q

What is the Cori Cycle?

A

The flow of lactate and glucose between the muscles and the liver

32
Q

When does the Cori Cycle start?

A

When the anaerobic conditions occur in active muscle, glycolysis begins to produce lactate

33
Q

What is the role of gluconeogenesis during the Cori Cycle?

A

Converts pyruvate to glucose, which is carried back to the muscles