Combined Biology - 4.4 Flashcards
Write the word and symbol equations for photosynthesis.
carbon dioxide + water → glucose + oxygen
6CO2 + 6H2O → C6H12O6 + 6O2
Why is photosynthesis described as an endothermic reaction?
Energy is transferred from the environment to the chloroplasts, by light.
Name four factors that affect the rate of photosynthesis.
- Temperature
- Light intensity
- Carbon dioxide concentration
- Amount of chlorophyll
Higher Q. Describe how both temperature and light intensity affect the rate of photosynthesis.
*this is just an example, you have to be able to do this for any graph with interacting limiting factors
- As light intensity increases, the rate of photosynthesis increases, for both lines.
- When light is no longer a limiting factor, the lines level off.
- Temperature must have been a limiting factor at 10 oC as 20 oC levels off higher than 10 oC.
Higher Q. Suggest ways in which gardeners can optimise conditions for photosynthesis in greenhouses.
- Heater – to increase temperature (e.g. in winter)
- Shade/ventilation/opening windows – to decrease temperature (e.g. in summer)
- Artificial lights – to increase light intensity
- Paraffin heaters – to increase both temperature and carbon dioxide levels
List the 5 ways that plants use the glucose produced in photosynthesis.
- Respiration
- Converted into insoluble starch for storage
- Used to produce fat or oil for storage
- Used to produce cellulose, which strengthens the cell wall
- Used to produce amino acids for protein synthesis
As well as glucose, what else do plants need to produce proteins?
Nitrates (that they absorb from the soil)
Higher Q. Use the inverse square law to calculate the light intensity when a lamp is placed 20 cm from some pond weed.
*This is just an example, you will need to be able to do this calculation when given the appropriate information.
Use the equation: light intensity ∝ 1/(distance (d)2)
Light intensity = 1/(20)2
Light intensity = 0.0025 arbitrary units
Is respiration an endothermic or exothermic reaction?
Exothermic reaction
Q. Which type of respiration releases most energy?
Q. Which type of respiration requires oxygen?
- Aerobic Respiration
- Aerobic Respiration
List three things that organisms need the energy from respiration for.
- Chemical reactions to build larger molecules
- Movement
- Keeping Warm
Write the word and symbol equations for aerobic respiration.
glucose + oxygen → carbon dioxide + water
C6H12O6 + 6O2 → 6CO2 + 6H2O
Write the word equation for anaerobic respiration in muscles.
glucose → lactic acid
Write the word equation for anaerobic respiration in plant and yeast cells.
glucose → ethanol + carbon dioxide
Name the process of anaerobic respiration in yeast cells.
Fermentation