Sports Biology

Question 1

Why do muscles anaerobically respire even if oxygen is present in intense exercise?

Answer 1

Because anaerobic respiration is a quicker way to produce ATP

Question 2

Why does anaerobic respiration quickly fatigue muscles?

Answer 2

Because of the build up of lactate
Produced when pyruvate is REDUCED to lactate

Question 3

What is done with the lactate produced in anaerobic respiration?

Answer 3

Converted to pyruvate to be used in aerobic respiration so chemical energy locked in pyruvate is not wasted

Question 4

How does build up of lactate cause muscle fatigue?

Answer 4

It lowers the pH
So alters H bonds and ionic bonds in proteins, changing tertiary structure (and active sites) in proteins so they are no longer complementary

Question 5

Effect of build up of lactate on actin, myosin and tropomyosin

Answer 5

Less effective as they have changed shape so can no longer pull etc so prevents contraction

Question 6

Effect of lactate build up on ATP hydrolase

Answer 6

The active site changes shape, so it is not complementary to its substrate ADP and Pi, preventing enzyme-substrate complexes forming to catalyse production of ATP which is needed in muscle contraction

Question 7

Why does short, intense exercise favour anaerobic respiration?

Answer 7

Because it can produce ATP faster

Question 8

Why does long endurance exercise prefer aerobic respiration?

Answer 8

Because 1 glucose produces 38 ATP which can last over a longer period

Question 9

What does phosphocreatine do?

Answer 9

Phosphorylates 1 ADP to ATP
To form creatine

Question 10

At rest, what does ATP do to creatine?

Answer 10

Phosphorylates it to phosphocreatine

Question 11

What is phosphocreatine?

Answer 11

Found in muscle fibres to resist changes in ATP to a small extent
Eg a lot of ATP is used, it can Phosphorylate ADP to resist the using up of it

Question 12

Types of muscle fibres

Answer 12

Fast and slow fibres

Question 13

Fast fibres are used for…

Answer 13

Short distance running eg sprinting

Question 14

Slow fibres are used for…

Answer 14

Long distance running eg marathons

Question 15

Respiration: fast vs slow fibres

Answer 15

Fast fibres = anaerobic respiration
Slow fibres = aerobic respiration

Question 16

Why are fast fibres better for short bursts of intense exercise?

Answer 16

Use mainly anaerobic respiration which produces ATP very quickly

Question 17

Why are slow fibres better for endurance exercise?

Answer 17

Because they prefer aerobic respiration which produces much more ATP per glucose so will not be used up quickly, can last a long time

Question 18

Slow/fast fibres: maintaining contractions

Answer 18

Slow fibres can maintain contractions for longer than fast fibres

Question 19

Fast/slow fibres: speed of contraction

Answer 19

Fast fibres contract faster than slow fibres

Question 20

Slow/fast fibres: numbers of mitochondria and capillaries

Answer 20

Slow fibres have a lot of mitochondria and capillaries
Fast fibres have less mitochondria and capillaries

Question 21

Why do Slow fibres have lower numbers of glycolysis enzymes in cytoplasm than fast fibres?

Answer 21

Because glycolysis is used mainly in anaerobic respiration
But slow fibres favour aerobic respiration so do not need this many enzymes to anaerobically respire compared to fast fibres

Question 22

Phosphocreatine concentrations: slow vs fast fibres

Answer 22

Slow fibres have lower concentration than fast fibres

Question 23

Myoglobin concentration: slow vs fast fibres

Answer 23

Slow fibres have a higher concentration of myoglobin compared to fast fibres

Question 24

Glycogen concentration: slow vs fast fibres

Answer 24

Slow fibres have a lower concentration compared to fats fibres

Question 25

What is myoglobin?

Answer 25

A storage protein for oxygen found in muscle fibres NOT BLOOD

Question 26

Myoglobin’s affinity to oxygen

Answer 26

Extremely high so only gives up oxygen at very low partial pressures

Question 27

How does myoglobin prolong aerobic respiration?

Answer 27

Very rapid release of oxygen at very low partial pressures so this can prolong aerobic respiration: allows oxygen present

Question 28

How does myoglobin delay anaerobic respiration

Answer 28

Because ensures oxygen is present for aerobic respiration

Question 29

Myoglobin vs haemoglobin

Answer 29

Myoglobin has no cooperative binding unlike haemoglobin Myoglobin = 1 polypeptide chain, haemoglobin = 4 polypeptide chain Myoglobin has 1 haem group to hold 1 oxygen, haemoglobin has 4

Question 30

Why do slow fibres have more myoglobin?

Answer 30

To prolong aerobic respiration to store oxygen