age 1 of 52
AQA A LEVEL BIOLOGY PAPER 2 ACTUAL EXAM
2025/2026 || QUESTIONS WITH CORRECT DETAILED
ANSWERS || 100% GUARANTEED PASS <LATEST
UPDATE>
describe and explain the steps in the light dependent reaction of
photosynthesis .......Answer.........1. photoionisation: light reaches
chlorophyll in PSII, which is absorbed by an electron, which
becomes excited and moves to a higher energy level.
2. the electron passes to a carrier protein in the thylakoid
membrane, and is passed down a series of carrier molecules
called an electron transfer chain.
3. as the electron moves down, energy is lost from the electron
and is released as ATP.
,age 2 of 52
4. the loss of electron from PSII is 'refilled' by an electron
produced by photolysis, which also produces hydrogen and
oxygen.
5. the lost electron reaches PSI, which absorbs light energy and
boosts another electron to a higher energy level (excitation).
6. this electron also goes down an electron transport chain.
7. this reaches the final electron acceptor which is a proton. they
combine to form H and reduce NADP to NADPH.
describe and explain the steps in the light independent reaction
pf photosynthesis. .......Answer.........1. CO2 diffuses into stroma
and combines with ribulose bisphosphate (RuBP) using the
enzyme rubisco.
,age 3 of 52
2. this forms an unstable 6 carbon molecule, which splits into 2 3
carbon molecules, glyercate-3-phosphate (G3P) .
3. G3P is reduced by NADPH to triose-phosphate (TP), which is
aided by ATP for energy.
4. TP can be converted into useful organic substances.
5. TP can also be reformed into RuBP using ATP.
describe glycolysis in respiration. give net formation.
.......Answer.........1. glucose is converted into phosphorylated
glucose by 2ATP. this makes it very reactive, so it splits into 2
triose phosphate (TP).
2. 2TP is then oxidised by 2NAD and 4 ATP is formed to form
pyruvate.
3. NET: 2ATP, 2Pyruvate, 2NADH, 2H+
, age 4 of 52
describe links reaction in respiration. give net formation.
.......Answer.........1. pyruvate diffuses into the matrix of
mitochondria.
2. pyruvate is oxidised by NAD. CO2 is lost. this forms acetate.
3. acetate and co-enzyme A combine to form acetyl co-enzyme
A.
4. NET: CO2, reduced NAD, acetyl co-enzyme A
describe krebs cycle in respiration. give net formation.
.......Answer.........1. acetyl co-enzyme A combines with 4 carbon
molecule (oxaloacetate) to form 6 carbon citric acid.
2. CO2 is lost (decarboxylation), molecule is oxidised by NAD
and ATP is produce. this forms 5 carbon compound.
3. it is oxidised by 2NADH and FAD, and is decarboxylated.
AQA A LEVEL BIOLOGY PAPER 2 ACTUAL EXAM
2025/2026 || QUESTIONS WITH CORRECT DETAILED
ANSWERS || 100% GUARANTEED PASS <LATEST
UPDATE>
describe and explain the steps in the light dependent reaction of
photosynthesis .......Answer.........1. photoionisation: light reaches
chlorophyll in PSII, which is absorbed by an electron, which
becomes excited and moves to a higher energy level.
2. the electron passes to a carrier protein in the thylakoid
membrane, and is passed down a series of carrier molecules
called an electron transfer chain.
3. as the electron moves down, energy is lost from the electron
and is released as ATP.
,age 2 of 52
4. the loss of electron from PSII is 'refilled' by an electron
produced by photolysis, which also produces hydrogen and
oxygen.
5. the lost electron reaches PSI, which absorbs light energy and
boosts another electron to a higher energy level (excitation).
6. this electron also goes down an electron transport chain.
7. this reaches the final electron acceptor which is a proton. they
combine to form H and reduce NADP to NADPH.
describe and explain the steps in the light independent reaction
pf photosynthesis. .......Answer.........1. CO2 diffuses into stroma
and combines with ribulose bisphosphate (RuBP) using the
enzyme rubisco.
,age 3 of 52
2. this forms an unstable 6 carbon molecule, which splits into 2 3
carbon molecules, glyercate-3-phosphate (G3P) .
3. G3P is reduced by NADPH to triose-phosphate (TP), which is
aided by ATP for energy.
4. TP can be converted into useful organic substances.
5. TP can also be reformed into RuBP using ATP.
describe glycolysis in respiration. give net formation.
.......Answer.........1. glucose is converted into phosphorylated
glucose by 2ATP. this makes it very reactive, so it splits into 2
triose phosphate (TP).
2. 2TP is then oxidised by 2NAD and 4 ATP is formed to form
pyruvate.
3. NET: 2ATP, 2Pyruvate, 2NADH, 2H+
, age 4 of 52
describe links reaction in respiration. give net formation.
.......Answer.........1. pyruvate diffuses into the matrix of
mitochondria.
2. pyruvate is oxidised by NAD. CO2 is lost. this forms acetate.
3. acetate and co-enzyme A combine to form acetyl co-enzyme
A.
4. NET: CO2, reduced NAD, acetyl co-enzyme A
describe krebs cycle in respiration. give net formation.
.......Answer.........1. acetyl co-enzyme A combines with 4 carbon
molecule (oxaloacetate) to form 6 carbon citric acid.
2. CO2 is lost (decarboxylation), molecule is oxidised by NAD
and ATP is produce. this forms 5 carbon compound.
3. it is oxidised by 2NADH and FAD, and is decarboxylated.
