Intro to metabolism

Question 1

Two different types of metabolism

Answer 1

anabolic and catabolic

Question 2

anabolic definition

Answer 2

synthesising larger molecules from smaller ones

synthesis of storage molecules, such as glycogen, triglycerides, glucose and ketone bodies

Question 3

catabolic definition

Answer 3

breaking down bigger molecules into smaller ones

fatty acid oxidation, glycogen and ketone body breakdown

Question 4

specific terms for the synthesis and breakdown of molecules

Answer 4

glycogenesis- glycogen
synthesis

lipogenesis- triglyceride synthesis

gluconeogenesis- glucose synthesis

ketogenesis- ketone body synthesis

glycolysis- glucose break down

fatty acid oxidation- beta oxidation

glycogenolysis- glycogen break down

ketolysis- ketone body break down

Question 5

Most abundant fatty acid

Answer 5

palmitic acid

Question 6

Features of biological oxidation

Answer 6

stepwise- complete/partial oxidation
some energy trapped chemically in a useful form, mainly ATP
yields waste products, such as CO2 and H2O

Question 7

What does a reaction require fo occur?

Answer 7

negative free energy

Question 8

what must happen for a reaction with a positive free energy?

Answer 8

coupling of ATP hydrolysis to an energy requiring process allows non-spontaneous reactions to occur

Question 9

3 different forms of fuel

Answer 9

glucose, fatty acids and amino acids

Question 10

masses of different fuels in 70kg man

Answer 10

blood glucose- 15g

liver glycogen- 70g

muscle glycogen- 200g

triglycerides in adipose- 11KG

amino acids- proteins throughout the body, however not a true storage form as they have a very important function

Question 11

energy stores in 70kg man

Answer 11

glycogen- 2500kj

triglycerides- 420,000kj

protein- 100,000kj

Question 12

Positives of cell and organelle compartmentalisation

Answer 12

• clustering of related functions serving a common purpose favoured by a common environment
• isolation, allows regulation
• removal of potentially harmful substances, free radicals

Question 13

negatives of cell and organelle compartmentalisation

Answer 13

isolation means that transport mechanisms required for substrates and products

Question 14

Summary of substrate selection for fatty acids

Answer 14

heart, skeletal muscle, liver, renal cortex

Question 15

Summary of substrate selection for glucose

Answer 15

brain, red blood cells, renal medulla, skeletal muscle

Question 16

Summary of substrate selection for amino acids

Answer 16

liver (except leu, ileu and val)

muscle (leu, ileu and val)

gut (gln, glu and asp)

renal cortex (gln)

Question 17

3 different types of short term control of metabolic flux + length + example

Answer 17

allosteric- milliseconds, binding of intracellular effector

covalent- secs to mins, addition or removal of molecule attached to the enzyme via a chemical bond that shares electrons

translocation- secs to mins, movement from one cell compartment to another

Question 18

long term control of metabolic flux + length + example

Answer 18

transcription/translation- hours to days, enzyme induction or suppression

Question 19

Tissue cycle definition

Answer 19

most tissues don’t metabolically exist in isolation, thus the substrates must be supplied form one organ to the next

Question 20

Example of a tissue cycle explained

Answer 20

cori cycle- the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver where it is converted to glucose, which then returns to the muscles