photosynthesis

Question 1

equation

Answer 1

CO2 + water —> oxygen and glucose

Question 2

photoautotrophs

Answer 2

make their own food through light

Question 3

heterotrophs

Answer 3

cant make their own food, rely on eating their food
-rely on plants for oxygen from photosynthesis

Question 4

compensation point

Answer 4

rate of photosynthesis and respiration are the same

Question 5

compensation period

Answer 5

time it takes for photosynthesis and respiration to reach compensation point

Question 6

structure of chloroplast

Answer 6

-stroma
-grana
-intermembrane space
-thylakoid (single)
-intergranal lamallae ( pole between the 2 granum)

Question 7

light dependant stage (non cyclic)

Answer 7

-Light hits PS 2, energy travels down accessory pigments to primary pigment reaction centre (chlorophyl a)
-2 electrons become excited and are passed along electron carriers through redox reactions
-electrons replaced by photolysis
-the energy released from the reactions causes protons to be pumped from stroma to thylakoid membrane space
-creates proton gradient, protons then pass through ATP synthase making ATP (by chemiosmosis) ADP phosphorylised
products are ATP and NADPH

Question 8

light independant (calvin cycle)

Answer 8

CO2 combines with RuBp with enzyme rubisco
-becomes carboxylated forming 6c compound (unstable to breaks down)
-2 x GP formed (glycerate 3 phosphate)
reduced to 2 x TP (triosephosphate)
NADPH –> NADP
2ATP –> 2ADP +2Pi

Question 9

limiting factors

Answer 9

light intensity - GP cannot be reduced to TPby NADPH , RuBP cannot be regenerated
co2 conc - RuBP accumulates as cannot join with CO2
temperature - GP not generated as rubisco denatures

Question 10

how respiration and photosynthesis link

Answer 10

Both important in cycling oxygen and carbon dioxide in the atmosphere