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Flashcards in Molecular Cell Biology Deck (14):
1

What is the basis of metabolism?

oxygen + fuel → CO2 + H20 + energy

2

How is energy obtained from fuel?

Oxidising it to CO2 and H20
Unused fuel can be stored as triacylglycerol (triglyceride - fat) or glycogen (carbohydrates or CHO)

3

What regulates fuel storage and retrieval?

Two endocrine hormones → insulin and glucagon

4

What is RMR?

Resting metabolic rate - the measure of energy required to maintain life

5

How does blood glucose vary over time?

Depends on food eaten
But, approximately 2 hours after meal = spike, 2 hours later = drop

6

What is BMI?

Body mass index - rough measure to determine ideal body weight

BMI = weight (kg) / height (m^2)

underweight < 18.5
healthy 18.5-24.9
overweight 25-29.9
obese 30-34.9
severely obese 35-39.9
morbidly obese > or equal to 40

7

What is catabolism?

the process of oxidation of fuels to produce CO2 and H2O - produces energy that is released by the transfer of electrons to O2 - this energy generates heat and ATP

- CO2 expired
- H2O excreted (sometimes it is used/sometimes made)
- heat maintains body temperature
- electrons transferred to electron transport chain
- ATP produced

8

What is ATP essential for?

Anabolic reactions
Active transport of molecules
Nerve impulses
Phosphorylation and cell signalling
Muscle contraction
Beating of cilia and flagella

9

What process are involved in the ATP-ADP cycle?

Energy production: ADP+Pi→ATP
carbohydrate, lipid, protein

Energy utilisation: ATP→ADP+Pi
biosynthesis (anabolism), muscle contraction, detoxification, active ion transport, thermogenesis

10

How much energy is produced by oxidation of carbs, proteins, lipids and alcohol?

Carb: CO2 + H2O → 4kcal/g
Protein: CO2 + H2O + NH4+ → 4kcal/g
Fats: 9kcal/g
Alcohol: CO2 + H20 → 7kcal/g

11

What is GSD type 1A?

Baby cannot regenerate own glucose → build up of glycogen in body cells → accumulation in tissues and organs, especially liver, kidney & small intestine

Signs and symptoms typically show at 3/4 months
Hypoglycaemia can → seizures

12

Where can aerobic glycolysis occur?

In tissues with mitochondria in the presence of O2

Cannot occur in red blood cells → pyruvate produced needs to enter mitochondria to complete aerobic respiration (rbc's don't have any)

13

How much ATP is released in aerobic glycolysis

36 moles ATP per mole of glucose

14

Outline glycolysis

Glucose → Glucose-6-phosphate (uses hexokinase, produces ADP)

Glucose-6-phosphate → fructose-6-phosphate (uses phosphofructokinase)

Fructose-6-phosphate → fructose-1,6-bisphosphate (produces ADP).

Fructose-1,6-bisphosphate → 2 phosphoglyceraldehyde molcules (PAG or G3P - glyceraldehyde-3-phosphate)

PAG/GP3 → pyruvate (uses pyruvate kinase, produces 2ATP per molecule and 1 NADH per molecule = 4ATP and 2NADH)