B4 Flashcards
What is photosynthesis?
Plants use light for their source of energy. The reaction plants use to trap this light is called photosynthesis.
Where does photosynthesis take place?
In the leaves of the plant.
Why is photosynthesis an endothermic reaction?
Photosynthesis takes in energy.
Which part of the plant absorbs light energy?
Chlorophyll is green and absorbs light energy.
What is the word equation for photosynthesis?
Carbon Dioxide + Water ———> Glucose + Oxygen
What is the chemical equation for photosynthesis?
6CO2 + 6H2O ———> C6H12O6 + 6O2
What are the four limiting factors of photosynthesis?
- Light intensity.
- Carbon dioxide.
- Temperature.
- Chlorophyll.
As we increase light intensity and the level of CO2, what happens to the rate of photosynthesis?
Increases.
After increasing light intensity and carbon dioxide levels, the rate of photosynthesis stops increasing. Why?
The factor has reached it’s maximum, so there is a new limiting factor.
Which leaf would carry out more photosynthesis, a light green leaf or a dark green leaf and why?
Dark green. Chlorophyll make a leaf green and they absorb sunlight. So, the more sunlight absorbed, the more photosynthesis occurs.
As we increase temperature, the rate of photosynthesis increases. However, the rate of photosynthesis decreases once we reach a certain point. Why?
- As we increase temperature, the enzymes involved in photosynthesis work faster so the rate increases.
- If we keep increasing the temperature, the enzyme denatures and the rate of photosynthesis decreases.
Explain the uses of glucose in plants.
1) Respiration - This takes place in the mitochondria. Plants also respire.
2) Storage - Glucose can be used to produce the insoluble storage molecule starch. The starch can be converted back when needed.
3) Protein - Glucose can be used to produce amino acids. These are used to synthesise proteins. Plants need to absorb nitrate ions from the soil to make these from glucose.
4) Cellulose- The cell wall is made of cellulose which gives it strength. This molecule is produced by glucose.
5) Fats and oils - Glucose can be converted into fats and oils as a storage form of energy.
What do we need energy for?
- Movement.
- To keep warm.
- Chemical reactions to build larger molecules.
What is respiration?
- Respiration is the reaction that supplies energy.
- Respiration is an exothermic reaction because it releases energy.
- Respiration takes place continuously in all living cells.
What is the word equation for aerobic respiration?
Glucose + Oxygen ———> Carbon Dioxide + Water
