Photosynthesis Flashcards
Write a balanced equation to summarise the process of photosynthesis
6CO2+6H2O—(light and chlorophyl)–> C6H12O6+6O2
Name the energy source for photosynthesis
sun
In what main part of a plant does most photosynthesis take place
Chloroplast
Name structures in plant cells in which photosynthesis takes place
Chlorophyll
What is the role of chlorophyl?
Absorb light needed for photosynthesis
Name gas used and produced by photosynthesis
Used: CO2
Produced: O2
Carbon dioxide is essential for photosynthesis. Where does it enter the leaf?
Stomata
From your knowledge of photosynthesis suggest a way to increase the yield of plants such as lettuces in a greenhouse?
Add more CO2 as it increases the level of photosynthesis
State a precise role for each of the following in photosynthesis
(i) Carbon dioxide
(ii) Water
(i) supplies Carbon to form glucose
(ii) photolysis of water supplies hydrogen and electrons for glucose formation
Suggest a way in which the rate of photosynthesis of plants in a greenhouse could be increased
adding more light/temperature to increase the rate of reaction
What is the relationship between the rate of photosynthesis and either the light intensity and carbon dioxide concentration
Light intensity: provides energy
Carbon dioxide: supplies carbon for glucose formation
The cells in the palisade layer contain many organelles that carry out photosynthesis. Suggest why the cells here obtain more if these that organelles than the cells in the spongy mesohpyl
They are closer to the upper epidermis meaning they have more light
What plant did you use for the photosynthesis experiment?
elodea
During the first stage of photosynthesis energised electrons enter two pathways. where do the energised electrons come from?
Chlorophyl
Give the alternative name for the first stage of photosynthesis
light stage
Two products of the light stage of photosynthesis are vital for the dark stage. Name these products
ATP, NADPH
In the second stage of photosynthesis compounds of the general formula Cx(H2O)y are formed. what name is given to this group of compounds?
Carbohydrates
Light energy trapped by chlorophyl is used to split water. List 3 products that result when water is split
- O2
- Protons
- Electrons
Name the simple compound that supplies the necessary energy for the second stage reactions in photosynthesis
ATP
Explain role of NADP- in photosynthesis
Protons from photolysis combine with NADP- to form NADPH
Why is the dark stage of photosynthesis given the alternative name of the light independent stage
it does not need/require light
Name a gas that is essential for the dark stage of photosynthesis
Carbon dioxide
What happens to water molecules when they reach the sites of photosynthesis
Photolysis
During photosynthesis oxygen is produced.
(i) From what substance is it produced?
(ii) In which stage of photosynthesis is oxygen produced?
(i) Water
(ii) 2
Give 2 possible fates of oxygen following its production
(i) released into atmosphere
(ii) respiration
In photosynthesis water is split into 3 products
- Name the three products
- State what happens to each
- oxygen, hydrogen and electrons
- oxygen: released in air
hydrogen: combines with NADP- to form NADPH
Electrons: replenish the original pair of electrons and they loose energy to form ATP
What does ATP stand for?
Adenine tri-phosphate
what is the role of ATP in cells
- supplies energy
- formation of glucose
In which of the stages of photosynthesis does ATP form?
Stage 1
From what simple compound does the plant obtain the H used to make compounds of the general formula Cx(H2O)y?
water
Give an account of role of each of the following in photosynthesis
- ATP
- NADP
- ATP:
- provides energy
- forms glucose in dark stage - NADP
- accepts electrons and hydrogen ions
- forms NADPH
State a precise role for each of the following in photosynthesis
- Carbon dioxide
- Water
- Carbon dioxide
- supplies carbon for glucose formation - Water
- photolysis of water supplies hydrogen and electrons for glucose production in dark stage
What do excess glucose molecules form?
starch
How can you achieve greater plant growth in greenhouses?
- increased temperature
- Increased lighting
- Increased CO2
Why is an aquatic plant such as elodea rather than terrestrial plant used when investigating the rate of photosynthesis?
To see and count gas bubbles easily
Name the cell organelle that contains chlorophyl
Chloroplast
Suggest why it is an advantage that chlorophyl contains a number of chemicals rather than just one
Absorb more energy
Outline the events of the dark stage of photosynthesis
- NADPH from the light stage supplies protons and electrons
- ATP supplies energy
- CO2 combines with electrons and with protons to form glucose
Explain how the dark stage is necessary for the continuation of the light stage
Products such as NADP AND ADP+P are used in the light stage
Using your knowledge of chlorophyll and photosynthesis describe 1 way to increase plant production in a greenhouse
Optimum temperature
increase the artificial lighting
increase the artificial CO2
Name 2 products of light dependant stage
- ATP
- NADPH
Outline the events of the light-independent stage
- ATP supplies energy
- NADPH provides electrons and protons
- CO2 is converted to glucose
Describe Pathway 1
- Light is absorbed
- It energises electrons
- electrons pass through electron acceptors
- electrons return back to chlorophyl
- electrons loose energy this energy is trapped by ADP and P to form ATP and water
Describe Pathway 2
- Light is absorbed and energises electrons
- electrons pass through electron acceptors
- 2 electrons are trapped by NADP+ forming NADP-
- photolysis occurs and splits water into oxygen, protons and electrons
- protons and NADP- combine forming NADPH
- Oxygen is released into the atmosphere
- electrons replenish the original pair of electrons
- The electrons loose energy forming ATP
Why can’t second stage happen without the first stage
Products of first stage (ATP and NADPH) is required for the second stage
