T5 energy transfers

Question 1

adaptations of chloroplasts for the LDR

Answer 1

-thylakoid membranes provide large SA to increase no of LDRs that occur
-network of proteins in grana that hold chlorophyll for max light absorption
-grana membranes have ATP synthase channels (for production of ATP) and are selectively permeable (proton gradient established)
-chloroplasts contain DNA and ribosomes so can quickly make proteins needed

Question 2

adaptations of chloroplasts for LIDR

Answer 2

-stroma contains all enzymes needed for LIDR
-stroma fluid is membrane bound, allowing high conc of enzymes to be maintained
-stroma fluid surrounds grana so products of LDR can readily diffuse into stroma
-chloroplasts contain DNA and ribosomes so can quickly make proteins needed

Question 3

process of light dependent reaction (LDR)

Answer 3

1. photoionisation
2. electron carriers & transport chain
3. chemiosmosis
4. NADP to reduced NADP
5. photolysis of light replace electrons

Question 4

process of light independent reaction (LIDR)

Answer 4

1. CO2 diffuses into leaf
2. CO2 reacts w ribulose bisphosphate (RUBP), catalysed by rubisco enzyme, to make 2 mols of glycerate-3-phosphate (GP)
3. reduced NADP used to reduce GP to 2 mols of triose phosphate (TP) using ATP
4. NADP reformed and goes back to LDR
5. 1/6 TP mols used to produce organic mols eg. starch, amino acids, cellulose, lipids
6. 5/6 TP mols used to reform RUBP, using ATP