Importance of energy transfers

Question 1

what are the 5 topics for importance of energy transfers?

Answer 1

1. photosynthesis
2. respiration
3. receptors
4. muscle contraction
5. energy and ecosystems

Question 2

what is the AO1 for energy transfers in photosynthesis?

Answer 2

• light energy converted into chemical energy in LDR
• describe photoionisation and electron transfer chain
• light energy used for photolysis of water
• kinetic energy lost in ETC used to pump H+ into thylakoif space
  ATP formed (chemical energy)

Question 3

what is the AO2 for energy transfers in photosynthesis?

Answer 3

• without this energy transfer, there would be no ATP and NADPH so no reduction of glycerate phosphate into triose phosphate
• triose phosphate cannot be converted into glucose, cellulose and lipids
• plants shrivel and die
• without cellulose, plant cell walls cannot be made

Question 4

what is the AO1 for importance of energy transfers in respiration?

Answer 4

• explain glycolysis in respiration
• chemical energy is transferred from ATP to glucose and glucose phosphate to make them more reactive
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Question 5

what is the AO2 for the importance of energy transfers in respiration

Answer 5

• this is important as without this energy transfer, pyruvate wouldnt be produced
• therefore all other stages of aerobic and anaerobic respiration would be inhibited
• gas exchange could not occur in the organism and they would die from asphyxiation

Question 6

what is the AO1 for the importance of energy transfers in receptors?

Answer 6

• mechanical pressure applied to pacinian corpuscle
• pressure widens stretch mediated channels
• sodium ions diffuse in - kinetic energy
• threshold value is reached causing a generator potential
• causes an action potential - electrical energy

Question 7

what is the AO2 for the importance of enrgy transfers in receptors

Answer 7

• enables organisms to respond to environemnt
• pacinian corpuscle found in skin, joints, needed for proprioception
• Convert mechanical energy into electrical energy ito action potenial which gets sent along to bran along sensory neurone
• allows effector to carry out response

Question 8

what is the AO1 for the importance of energy transfers in muscle contraction?

Answer 8

• describe sliding filament theory
• ATP binds to myosin head to break crossbridge
• ATP hydrolysed to ADP + Pi to cause myosin head to move back to og position - kinetic energy
• ADP attached to myson head allows crossbridge
• release allows powerstroke- actin is pulled inwards between myosin - kinetic energy

Question 9

what is the AO2 for the importance of energy transfers in muscle contraction?

Answer 9

• without the production of kinetic energy from ATP molecules, myosin would stay bound to actin causing muscle stiffness
• without muscle contraction, the function of the human body is inhibited
  internal and external intercoastal muscles wouldnt be able to contract
  required for inspiration/expiration

Question 10

what is the AO1 for importance of energy transfers in ecosystems?

Answer 10

• energy trasnfer through trophic levels - producers convert light energy to chemical energy
• NPP is the chemical energy store in plant biomass after respiratory losses to the environment (NPP= GPP - R)
• only biomass from NPP is passed to next trophic level
• energy is lost at each trophic level due to respiration, movement/maintenance of body temperature, faeces/urine and the parts of organism thats not eaten. N = I - (F+R)

Question 11

what is the AO2 for energy transfers in ecosystems?

Answer 11

• The energy transfer between the producers and consumers is important as it means that organisms further up the food chain are gaining sufficient energy for respiration and in order to survive
• if this didnt occur then it would lead to the death of quaternary consumers who rely on others to gain energy