Photosynthesis

Question 1

where does photosynthesis happen?

Answer 1

in the chloroplast of the leaf.

Question 2

what are the adaptation of the leaf in relation to photosynthesis?

Answer 2

– large SA to absorb sunlight
– arrangement of leaves on the plant to minimise overlapping
– thin, to absorb light
– transparent cuticle
– long, narrow upper mesophyll cells packed
– numerous stomata
– many air spaces
– network of xylem

Question 3

what is the overall equation for photosynthesis?

Answer 3

6CO2 + 6H20 –> C6H1206 +6O2

Question 4

what are the three main stages of photosynthesis?

Answer 4

– capturing of light energy
– light-dependent reaction
– light-independent reaction

Question 5

what are the distinct regions inside the chloroplast?

Answer 5

– the grana
– the stroma

Question 6

what is oxidation?

Answer 6

when a substance gains oxygen or loses hydrogen the process is called oxidation

Question 7

what is reduction

Answer 7

when a substance looses oxygen or gain hydrogen and gains electrons

Question 8

what is photolysis of water?

Answer 8

the loss of electrons when light strikes a chlorophyll molecule leaving it short of electrons

Question 9

how are chloroplasts structurally adapted to their function of capturing sunlight?

Answer 9

– the thylakoid membrane provide a large surface area for the attachment of chlorophyll
– a network of proteins in the grana hold the chlorophyll in a very precise manner that allows maximum absorption of light
– the granal membranes have ATP synthase channels
– chloroplasts contain both DNA and ribosomes so they can quickly and easily manufacture some of the proteins involved.

Question 10

what are the stages of the calvin cycle?

Answer 10

– carbon dioxide from the atmosphere diffuses into the leaf through the stomata and dissolves in water around the mesophyll cells. Then diffuses into stroma
– in stroma, CO2 reacts with RuBP catalysed by rubisco
– the reaction between CO2 and RuBP produces two molecules of the GP
– reduced NADP is used to reduce GP to TP using energy from ATP
– NADP is reformed and goes back to the light-dependent reaction to be reduced again
– TP molecules are converted to organic substances
– most TP molecules are used to regenerate RuBP

Question 11

ways the chloroplast is adapted to carrying out the light-independent reaction of photosynthesis

Answer 11

– the fluid of the stroma contains all the enzymes needed to carry out this reaction
– the stroma fluid surrounds the grana
– contains both DNA and ribosomes so it can quickly manufacture proteins