Week 3

Question 1

What is metabolism?

Answer 1

The sum of all chemical reactions in the body

Question 2

What percentage are different parts of metabolism?

Answer 2

Resting metabolic rate - about 70%
Digestion - 10%
Exercise - 20%

Question 3

anabolic vs catabolic

Answer 3

anabolic - building
catabolic - breakdown

Question 4

What is energy?

Answer 4

the capacity to do work, either potential or kinetic

Question 5

how many joules in a calorie

Answer 5

4.2kj = 1kcal

Question 6

For a thermodynamic cycle what does the net heat supplied equal?

Answer 6

the net work done by the system

Question 7

what makes up ATP?

Answer 7

Three phosphate groups, adenine - a 5x nitrogenous base with a connecting ribose sugar molecule

Question 8

what does one ATP power?

Answer 8

one miosin head one step (3pN isometric force, 11nM disatnce)

Question 9

How uch ATP is stored in the muscle?

Answer 9

8mmol/kg wet weight of muscle

Question 10

How long does the ATP in muscles power exercise for?

Answer 10

2 seconds without regenerating the ATP

Question 11

what is our immediate source of resynthesising ATP?

Answer 11

the phosphocreatine system

Question 12

how is phosphocreatine split?

Answer 12

By the enzyme creatine kinaseh

Question 13

what is phosphocreatine split into?

Answer 13

a free phosphate and creatine

Question 14

how does the phosphocreatine system create ATP?

Answer 14

Energy released from breaking the phosphocreatine bond is used to create ATP from ADP and free phosphate

Question 15

How long does the phosphocreatine system last?

Answer 15

between 6 and 10 seconds

Question 16

How much creatine can be stored in muscle?

Answer 16

between 150-160 mmol/kg dried muscle

Question 17

How does taking creating help?

Answer 17

improves recovery of phosphocreatine and ability to resynthesise phosphocreatine = longer training sessions

Question 18

What is glcolysis also known as?

Answer 18

the lactic acid system

Question 19

Where does glycolysis take place?

Answer 19

In the cytosol

Question 20

what happens in glycolysis?

Answer 20

Glucose is broken into 2 pyruvate molecules and produces 2x ATP.

Question 21

Does lactic acid exist in the body?

Answer 21

No it dissociates into lactate and hydrogen ions as soon as it is formed

Question 22

what is phosphorylation?

Answer 22

adding a phosphate to ADP to form ATP

Question 23

What is the key enzyme that controls glycolysis?

Answer 23

phosphofructokinase (PFK)

Question 24

Outline the process of glycolysis

Answer 24

hydrogen carriers (Nicotinamine denine dinucleotide NAD) in the cytosol prevent build up of hydrogen.
they’re reduced to NADh , carry H ions to mitochondria for aerobic respiration

Question 25

When pyruvate is converted to lactate how many ATP are produced?

Answer 25

2 or 3 ATP

Question 26

If pyruvate doesn’t form lactate what can it form?

Answer 26

Acetyl coenzymeA - when it is oxidised

Question 27

What is the process involving acetyl coenzyme A called?

Answer 27

krebs cycle

Question 28

What happens to acetylcholine A in the krebs cycle?

Answer 28

H+ and CO2.

Question 29

what are 2 hydrogen carriers?

Answer 29

NAD and FAD

Question 30

Where do hydrogen carriers take hydrogen to?

Answer 30

from the sarcoplasm to the mitochondria

Question 31

How does the krebs cycle produce ATP?

Answer 31

The hydrogen ions build up and flood into the inner membrane of the mitochondria. The energy produced is used to combine ADP and free phosphate - chemiosmosis

Question 32

How are the hydrogen ions removed from the mitochondria in the krebs cycle?

Answer 32

they combine with the oxygen to form water.

Question 33

How many ATP does the aerobic system produce from one moleucle of glucose?

Answer 33

36-38 ATP
2 from glycolysis, 2 Krebs, 34 from electron transport chain

Question 34

What does FAD stand for?

Answer 34

Flavin adenine dinucleotide