animal responses

Question 1

action of adrenaline

Answer 1

• adrenaline = 1st messenger
• binds to receptors on target cells
• activates adenyl cyclase ( ATP –> cAMP)
• cAMP ( 2nd messenger) activates protein kinases
• protein kinases activate glycogen to glucose

Question 2

suggest why reduced heart rate is sometimes seen in people who are aerobically fit

Answer 2

• higher stroke volume
• greater thickness of heart muscle

Question 3

sprinters need large amounts of energy in short periods of time. suggest how sprinters can create so much energy without needing to carry out aerobic respiration

Answer 3

• have high levels of phosphocreatine stores
• use the ATP thats stored there

Question 4

explain why glucose is needed for the contraction of skeletal muscle

Answer 4

• to break the AM crossbridge
• ATP hysrolysed to ADP + Pi
• ATP needed for the active transport of Ca2+ ions into the sarcoplasmic reticulum.