Photosynthesis

ATP and reduced NADP are two products of the light-dependent reactions. Describe one function of each of these substances in the light-independent reactions?

1)(ATP) Provides energy for Glycerate Phosphate → Triose Phosphate 2)Reduces GP to TP

Humans synthesise more than their body mass of ATP each day. Explain why it is necessary for them to synthesise such a large amount of ATP?(2 marks)

1)ATP cannot be stored 2)ATP only release a small amount of energy at time

Describe how ATP is made in mitochondria?(6 marks)

1)ATP produced in Krebs cycle 2)Krebs cycle produces reduced NAD 3)Electrons released from reduced NAD 4)Electrons pass along ETC 5)Energy released 6)ADP + Pi produced

What is the role of chlorophyll in photolysis?(3 marks)

1)Absorbs light 2)loses electrons 3)Accepts electrons from water

Describe the light-independent reactions of photosynthesis and explain how they allow the continued synthesis of hexose sugars?(6 marks)

1)CO2 combines with RuBP 2)This produces two molecules of glycerate(3-) phosphate 3)Reduced to Triose phosphate 4)Triose phosphate forms hexose 5)RuBP regenerated 6)10 molecules of 3C and GP forms 6 molecules of 5C

In the light-independent reaction of photosynthesis, the carbon in carbon dioxide becomes carbon in triose phosphate. Describe how?(5 marks)

1)CO2 combines with RuBP 2)This produces two molecules of glycerate(3-) phosphate 3)Reduced to Triose phosphate 4)Using reduced NADP 5)Using energy from ATP

During photosynthesis, oil-palm trees convert carbon dioxide into organic substances. Describe how?(6 marks)

1)CO2 combines with RuBP 2)This produces two molecules of glycerate(3-) phosphate 3)Reduced to Triose phosphate 4)Using reduced NADP 5)Using energy from ATP 6)Triose phosphate converted to ribulose bisphosphate 7)Takes place in light-dependant reaction

Anolis sagrei is a species of lizard that is found on some of the smallest Caribbean islands. Describe how you could use the mark-release-recapture method to estimate the number of Anolis sagrei on one of these islands?(4 marks)

1)Capture, mark and release 2)Method of marking does not harm the lizard 3)Leave sufficient time for lizards to randomly distribute on island before collecting a second sample 4)Population=No.1st sample x No.2nd sample divided by no. of marked lizards in second sample

Energy enters most ecosystems through the light-dependent reaction of photosynthesis. Describe what happens during the light-dependent reaction?(5 marks)

1)Chlorophyll absorbs light energy 2)Excites electrons 3)Electrons move along ETC releasing energy 4)Energy used to join ADP and Pi to form ATP 5)Photolysis of water produces protons, electrons and oxygen 6)NADP reduced by Hydrogen

In the light-dependent reaction of photosynthesis, light energy generates ATP. Describe how?(5 marks)

1)Chlorophyll absorbs light energy 2)Excites electrons 3)Electrons move along ETC releasing energy 4)Energy used to join ADP and Pi to form ATP 5)Photolysis of water produces protons, electrons and oxygen 6)NADP to NADPH

How is the energy of light converted into chemical energy in the light-dependent reactions?(3 marks)

1)Electrons excited 2)Moves along ETC releasing energy 3Produces ATP

Crops use light energy to produce photosynthetic products. Describe how crop plants use light energy during the light-dependent reaction?(5 marks)

1)Excites electrons 2)Electrons move along ETC releasing energy 3)Energy used to join ADP and Pi to form ATP 4)Photolysis of water produces protons, electrons and oxygen 5)NADP reduced by hydrogen

Describe the role of electron transport chains in the light-dependent reactions of photosynthesis?

1)Excites electrons 2)Electrons move along ETC releasing energy 3)Energy used to join ADP and Pi to form ATP 4)Photolysis of water produces protons, electrons and oxygen 5)NADP reduced by hydrogen

Changes in ecosystems can lead to speciation. A high concentration of copper in soil is toxic to most plants. In some areas where the soil is polluted with copper, populations of grasses are found to be growing. These populations of grass belong to a species also found growing on unpolluted soils. It has been suggested that a new species of grass may evolve on soil that has been polluted with copper. Explain how this new species might evolve?(5 marks)

1)Geographical isolation 2)No interbreeding between populations 3)Variation due to Mutation 4)Different selection pressures 5)Selective organisms survive and reproduce 6)Leads to an increase in allele frequency

On islands in the Caribbean, there are almost 150 species of lizards belonging to the genus Anolis. Scientists believe that these species evolved from two species found on mainland USA. Explain how the Caribbean species could have evolved?

1)Geographical isolation 2)No interbreeding between populations 3)Variation due to Mutation 4)Different selection pressures 5)Selective organisms survive and reproduce 6)Leads to an increase in allele frequency

Where does the light-dependant reaction take place?

Granum/Thylakoid membrane

Which process is the source of the ATP used in the conversion of glycerate 3-phosphate (GP) to triose phosphate?

Light dependant reaction

Give two products of the light-dependent stage of photosynthesis?

Reduced NADP and ATP

Where does the light-independent reaction take place?

Stroma

Where precisely in a cell does the Calvin cycle take place?(1 mark)

Stroma

The products of the light-dependent stage are used in the light-independent stage of photosynthesis. What are these products used for?

To make sugars

Large areas of tropical forest are still found on some Caribbean islands. The concentration of carbon dioxide in the air of these forests changes over a period of 24 hours and at different heights above ground. Use your knowledge of photosynthesis and respiration to describe and explain how the concentration of carbon dioxide in the air changes: • over a period of 24 hours • at different heights above ground. (5 marks)

1)High conc. of carbon dioxide is linked with respiration at night 2)No photosynthesis takes place at night only during the day as it requires light 3)The rate of photosynthesis greater than rate of respiration 4)Decrease in carbon dioxide conc. with height 5)At ground level, less photosynthesis and more respiration

The concentrations of carbon dioxide in the air at different heights above ground in a forest changes over a period of 24 hours. Use your knowledge of photosynthesis to describe these changes and explain why they occur?(5 marks)

1)High conc. of carbon dioxide is linked with respiration at night 2)No photosynthesis takes place at night only during the day as it requires light 3)The rate of photosynthesis greater than rate of respiration 4)Decrease in carbon dioxide conc. with height 5)At ground level, less photosynthesis and more respiration

Plants produce ATP in their chloroplasts during photosynthesis. They also produce ATP during respiration. Explain why it is important for plants to produce ATP during respiration in addition to during photosynthesis?(5 marks)

1)In the dark there is no ATP production In photosynthesis 2)Some tissues unable to photosynthesise 3)ATP cannot be stored 4)Plant uses more ATP than produced in photosynthesis 5)ATP for active transport

Lowering the temperature has very little effect on the light-dependent reaction, but it slows down the light-independent reaction. Explain why the light-independent reaction slows down at low temperatures?

1)Not a photochemical reaction 2)Less Kinetic energy

What are the amount of Carbons in the following parts of the Light-Independent reaction: 1-Carbon dioxide 2-RuBP 3-GP 4-TP 5-Glucose

1)One 2)Five 3)Three 4)Three 5)Six

After harvesting, the remains of crop plants are often ploughed into the soil. Explain how microorganisms in the soil produce a source of nitrates from these remains?(5 marks)

1)Proteins are turned into ammonia 2)By saprobionts 3)Ammonia turns into nitrite 4)Nitrite turns into Nitrate 5)By nitrifying bacteria

Some bacteria use hydrogen sulfide, H2S, to produce organic compounds. The hydrogen sulfide has a similar role to that of water in photosynthesis. A simple equation for this process in bacteria is shown below: hydrogen sulfide + carbon dioxide → glucose + sulfur + water Suggest what the hydrogen sulfide is used for in these bacteria? (2 marks)

1)Provides hydrogen and electrons 2Electrons provided for ETC

ATP is useful in many biological processes. Explain why?(4 marks)

1)Releases energy in small amounts 2)Broken down in one step 3)Phosphorylates and lowers activation energy 4)Reformed

Much of Indonesia is covered with forest. Large areas of forest have been cleared and planted with oil-palm trees to be used in the production of fuel. In these forests, nitrogen in dead leaves is made available to growing plants by the action of bacteria. Describe the role of bacteria in making the nitrogen in dead leaves available to growing plants?(5 marks)

1)Saprobionts break down proteins and release enzymes. 2)Ammonia is produced 3)Ammonia> nitrite>nitrate 4)Nitrification takes place 5)Oxidation takes place

Explain why the increase in the dry mass of a plant over twelve months is less than the mass of hexose produced over the same period?(3 marks)

1)Some hexose used in respiration 2)CO2 produced 3)Some parts of the plant are eaten

The photolysis of water is an important part of the process of photosynthesis. Describe what happens in the photolysis of water? (2 marks)

1)Water forms H+ and e- 2)Oxygen is formed 3)Excites electrons