1. Instructions for making revision cards
1 Print off slides 2–17 back to back on card. 2 Cut out each card. 3 On the front of each card is a question or a requirement from the specification. 4 On the back is the answer to the question or what is required by the specification. Try to add your own pictures and key words to the front of each card to help trigger your recall.

2. Write the word equation for photosynthesis.
Identify what is needed and what is produced.
What is an autotroph?
What is a heterotroph?
What are the similarities and differences between respiration and photosynthesis?
Give an example of a primary pigment.
Give examples of accessory pigments.
What are the similarities and differences between accessory and primary pigments.
What happens in non-cyclic phosphorylation?
Relate the structure of chloroplasts to their function.
What happens in cyclic phosphorylation?

3. Structure and function of a chloroplast
A heterotroph is an organism that uses organic substrates to get its chemical energy for its life cycle. Examples include fungi, animals, protoctists.
An autotroph is an organism that produces complex organic compounds from simple inorganic molecules using energy from light (by photosynthesis) or inorganic chemical reactions, e.g. plants.
Water and CO2 are needed.
Carbohydrates are produced (but also lipids and amino acids). Oxygen is released.
In photosynthesis, light energy excites electrons.
Respiration in plants and animals depends on the products of photosynthesis.
Similarities:
Electrons split from hydrogen atoms.
Energy released from movement of electrons drives synthesis of ATP.
ATP synthesised by phosphorylation of ADP.
Differences:
In respiration, complex molecules are broken down to less complex molecules.
In photosynthesis, simple organic molecules are built up to form more complex organic molecules.
Primary e.g.
Primary pigment, e.g. chlorophyll a, absorbs light and excites electrons directly.
Accessory pigments, e.g. chlorophyll b, xanthophyll and carotene, absorb light and pass energy to primary pigment.
Accessory e.g.s
Reduced NADP and ATP formed. Uses photosystem 1 and photosystem 2. e– from H atom excited by light.
Only ATP formed
Uses photosystem 1 only
e– recycled
Structure and function of a chloroplast
Stroma contains enzymes for light independent reactions.
Ribosomes for protein synthesis
Inner membrane helps regulate entry and exit of substances.
Granum is a stack of thylakoids. Stacking thylakoids maximises light capture.
Starch grains store the products of photosynthesis.
Outer membrane.
Thylakoids contain chlorophyll and other pigments which can absorb light at a variety of wavelengths.

4. Describe an experiment to investigate the factors affecting the rate of photosynthesis.
What is the role of water in photosynthesis?
What happens in photolysis?
What are ATP and reduced NADP used for in the light-independent reaction (LIR)?
What are the products of the light-dependent reaction (LDR)?
What happens to CO2 in the light-independent reaction (LIR)?
What happens to the concentrations of glycerate 3-phosphate (GP), ribulose bisphosphate (RuBP), and triose phosphate (TP) when the CO2 concentration falls?
What happens to the concentrations of GP, RuBP and TP when the light intensity increases?
What happens to 5/6 of the triose phosphate (TP) formed?

5. Water is the source of H ions and electrons.
Light excites electrons in photosystem 2 and water is split to form H+ ions, oxygen and electrons.
Water is the source of H ions and electrons.
Photolysis is the splitting of water to form H+, e–, and oxygen by light.
This happens only in the primary pigment.
The light is absorbed by the primary pigment or the accessory pigment.
One of three factors — light intensity, temperature and carbon dioxide concentration — can be altered in turn while the other two are maintained.
The volume of gas evolved can be measured as an indicator of the rate of photosynthesis. Elodea is used because it is easier to capture gas from under water.
Need to prevent lamp from emitting heat.
Carbon dioxide is the source of carbon to form the products of photosynthesis (which include carbohydrate, amino acid, lipids).
Carbon from carbon dioxide is fixed into a 6-carbon molecule, catalysed by the enzyme RuBisCO.
ATP provides the energy needed to convert GP to TP.
Reduced NADP passes H to GP to form TP.
Products of the LDR:
reduced NADP (used in LIR)
ATP (used in LIR)
oxygen (waste product)
Decreasing light intensity: less ATP and reduced NADP, so less TP is made since ATP and reduced NADP are needed to make TP from GP.
Decreasing light intensity: more GP because RuBP can be converted to GP but without ATP and reduced NADP GP will not be used up to make TP.
Decreasing light intensity: less ATP and reduced NADP so less RuBP because RuBP is still being used to make GP but is not regenerated as GP cannot be made into TP (needed to make RuBP).
As carbon dioxide increases, TP Increases. Because more CO2 is fixed, so more GP is made, so more TP.
As carbon dioxide increases, GP increases. Because more CO2 is fixed, so more GP is made.
As carbon dioxide increases, RuBP decreases. Because more CO2 is fixed, so more GP is made, so more RuBP is used up.
5 out of 6 TPs are recycled to form RuBP

6. What happens to the concentrations of GP, RuBP and TP when the temperature rises too high?
Draw a graph to show the effect of changing concentration of carbon dioxide on the rate of photosynthesis.
Draw a graph to show the effect of changing temperature on the rate of photosynthesis.
Draw a graph to show the effect of changing light intensity on relative levels of TP, GP and RuBP.
Draw a graph to show the effect of increasing carbon dioxide on relative levels of TP, GP and RuBP.
Draw a graph to show the effect of increasing light intensity on the rate of photosynthesis.
What happens in the light-dependent reaction?
What happens in the light independent reaction?
Name the products of the light-dependent reaction.

7. As temperature increases TP increases
As temperature increases TP increases. But at high temperatures [TP] will decrease because the enzyme RuBisCO denatures and less carbon dioxide fixed, so less GP will be made and so less TP is made.
As temperature increases GP Increases. But at high temperatures will decrease because the enzyme RuBisCO denatures and less carbon dioxide fixed, so less GP will be made and so less TP is made.
As temperature increases RuBP decreases because as the rate of enzyme action increases more RuBP is used up. When the RuBisCO denatures at high temperature less RuBP will be used up as CO2 is not fixed.
At low temperatures, rate is limited by temperature since molecules require energy to collide and react in the LIR. At higher temperatures (not too high) carbon dioxide and light intensity limit rate.
Reduced NADP and ATP are used in the stroma in the Calvin cycle. Carbon dioxide is fixed joining with ribulose bisphosphate to make GP in the presence of the enzyme rubisco. GP is then converted to TP. Most TP is recycled to re-make ribulose bisphosphate. 1/6 of TP made is used to make carbohydrate, lipids or amino acids.
In the thylakoids water is split by photolysis and H+ and e– are released. Light is absorbed by the primary pigment and excites electrons. In non-cyclic phosphorylation NADP reduced and ATP are generated using photosystem 1 and 2.
ATP and reduced NADP are made and oxygen is released as a waste product.

8. Define photosynthetic pigment.
Give an example and describe the difference between accessory and primary photosynthetic pigments.
What happens in cyclic photophosphorylation?
What happens in non-cyclic photophosphorylation?
What is photolysis?
What is the role of water in the light-dependent reaction?
What happens in the thylakoid?
What happens in the stroma?
What is ribulose bisphosphate carboxylase oxygenase (RuBisCO) and what does it do?

9. Photolysis is the splitting of water using light energy.
Accessory pigments pass energy to primary pigments. The energy is then used to excite electrons.
Pigment that absorbs light and passes that energy onto the primary pigment where the light energy is used to excite electrons.
Water is the source of hydrogen ions and electrons. Oxygen is released as a waste product.
Photolysis is the splitting of water using light energy.
In non-cyclic phosphorylation, ATP and reduced NADP are formed as electrons are excited by light photons in PS1 and PS2 and electrons are not recycled.
RuBisCO is an enzyme that catalyses the fixiation of the carbon in carbon dioxide to form GP.
The light-independent reaction (Calvin cycle)
The light-dependent reaction occurs in the thylakoid.
In cyclic phosphorylation, light energy is used to excite electrons to higher energy levels. As an electron passes down the carriers, the energy is used to join ADP with phosphate to ATP. Only PS1 is used.

10. What is the role of carbon dioxide in the Calvin cycle?
What are the products of the Calvin cycle?
What products can be made from triose phosphate (TP).
What happens to most TP in the Calvin cycle?
Describe the effect on the rate of photosynthesis, and on levels of GP, RuBP and TP, of changing carbon dioxide concentration.
Describe the effect on the rate of photosynthesis, and on levels of GP, RuBP and TP, of changing temperature.
Describe the effect on the rate of photosynthesis, and on levels of GP, RuBP and TP, of changing light intensity.
Discuss limiting factors in photosynthesis with reference to carbon dioxide concentration.
Discuss limiting factors in photosynthesis with reference to light intensity.

11. Carbohydrate, lipid, amino acids Products of the Calvin cycle:
Triose phosphate used to make hexose sugar, used in the formation of carbohydrates, lipids and amino acids.
Most TP is recycled.
Carbon dioxide is the source of carbon used in the Calvin cycle.
Increasing temperature too high (which denatures the enzyme)
GP levels fall as can’t fix carbon.
TP levels fall as no GP and TP is recycled.
RuBP levels rise as not converted to GP.
Increasing carbon dioxide concentration causes:
GP levels increase (more CO2 fixed)
TP levels increase as more GP converted.
RuBP levels fall as it is used up to make GP.
Recycled to make ribulose bisphosphate.
When light intensity is high then the level of carbon dioxide and temperature will be the limiting factors.
When carbon dioxide levels are high then the light intensity and temperature will be the limiting factors.
Increasing light intensity causes:

12. What is photoexcitation?
Discuss limiting factors in photosynthesis with reference to temperature.
Describe how to investigate experimentally the factors that affect the rate of photosynthesis
What is photoexcitation?
What is reduction?
How is NADP reduced?
What happens when carbon dioxide reacts with ribulose bisphosphate (RuBP)?
How is glycerate 3-phosphate (GP) changed into triose phosphate (TP)?
How do farmers use limiting factors to maximise yield in food production?
What happens to the oxygen in the LDR?

13. Carbon is fixed into RuBP to make glycerate 3-phosphate.
Photoexcitation is the excitation of electrons using light energy (photons).
Use radioactively labelled carbon to track the absorption and fixation of carbon from carbon dioxide to RuBP, GP and TP.
Ensure all factors are maintained the same apart from the factor being investigated.
When temperature is not too high then the level of carbon dioxide and temperature will be the limiting factors.
Carbon is fixed into RuBP to make glycerate 3-phosphate.
NADP is reduced by the addition of hydrogen ions, which are obtained from the photolysis (splitting) of water.
Reduction is the gain of electrons or hydrogen ions.
OIL RIG
Oxygen is a waste product. It is released into the atmosphere via the stomata.
Optimising the temperature, providing carbon dioxide and increasing light intensity increases the rate of photosynthesis, e.g. greenhouses.
GP reacts with the H+ ions (supplied by the reduced NADP). Energy from ATP is used to make TP from GP.

14. What is photophosphorylation?
What colour corresponds to the wavelength of light that most plants reflect?
What is photophosphorylation?
What happens during carbon fixation in the Calvin cycle?
How many turns of the Calvin cycle does it take to produce one molecule of glucose?
What is the relationship between gross primary productivity, net
primary productivity and plant respiration?
Name three accessory pigments. What is the function of accessory pigment?
What kind of pigment is chlorophyll a? What is the function of chlorophyll a?

15. RuBP + carbon dioxide  glycerate 3-phosphate.
The reaction is catalysed by the enzyme RuBisCO.
The addition of phosphate (ADP + Pi  ATP) using energy from light.
Green light
Chlorophyll b, xanthophylls and carotene
Their function is to absorb different wavelengths of light and pass the energy onto the primary pigment.
Gross primary productivity = net primary productivity + plant respiration
Six
Chlorophyll a is a primary pigment.
The function of the primary pigment is to receive the energy from the accessory pigments. This in turn excites the electrons, which are then released.
Absorb light energy and excite electrons using this energy.

16. What does an absorption spectrum show?
Why do plants have more than one pigment?
What does an action spectrum show?
Where are photosynthetic pigments found?
What is the difference between photosystem 1 and photosystem 2 in terms of the pigment they contain?
What are the uses of ATP?
Describe the structure of a chloroplast
Relate the structures and functions of a chloroplast
How are electrons moved from one area to another?

17. ATP can be used to transfer energy for a reaction to occur.
Allows them to absorb more wavelengths of light, and therefore they are reflecting less.
ATP can be used to transfer energy for a reaction to occur.
Can be used in phosphorylation to add Pi to another molecule
PS1 contains P700 nm, and PS2 contains P680 nm. These two photosystems absorb light at different wavelengths.
Thylakoids contain primary and accessory pigments.
Electrons are moved via electron carriers.
Stroma (matrix containing enzymes for the Calvin cycle).
Double membrane to control entry and exit of substances.
Thylakoids contain pigments for absorption of light.
Grana optimise surface area for absorption of light.
Chloroplasts are flattened spheres to optimise surface area for absorption of light. Contain stacked thylakoids to increase surface area for light capture.
Shows the rate of photosynthesis at different wavelengths of light.
Shows the wavelengths of light that each pigment absorbs