biogenetics revision Flashcards
define photosynthesis
plants making use of the sun’s energy to make food.
Plants make glucose from what?
CO2 and water, using energy from light.
Photosynthesis is [endothermic/exothermic] (pick one)
Endothermic
Why is photosynthesis an endothermic reaction?
Because photosynthesis needs an input of energy from the environment
What is the word equation for photosynthesis?
carbon dioxide + water —(light)—-> glucose + oxygen
What is the symbol equation for photosynthesis?
CO2 + H2O —–> C6H12O6 + O2
summarise an investigation for the effect of light intensity on the rate of photosynthesis:
- cut a piece of pond weed and place it in a boiling tube filled with sodium hydrogen carbonate solution
- set up an LED light and 10cm from the tube, leave to settle
- start the stopwatch and count the no. of bubbles in 1 minute.
- repeat and calculate the mean
- repeat, altering the lamp’s distance
Why do we fill the boiling tube with sodium hydrogen carbonate solution in a light intensity investigation?
Makes sure that CO2 is not a limiting factor in the experiment.
Why do we use specifically LED lamps in a light intensity investigation?
LED lamps produce less heat, which makes the experiment more fair because it reduces the effect of temperature on the experiment.
The rate of photosynthesis [increases/decreases] with higher concentrations of CO2, up to a point.
The rate of photosynthesis increases with higher concentrations of CO2, up to a point.
Name 3 limiting factors of photosynthesis.
light intensity, temperature, amount of chlorophyll.
photosynthesis is an __________ controlled reaction.
photosynthesis is an [enzyme] controlled reaction.
Because photosynthesis is an enzyme controlled reaction, if the temperature increases too much, the enzymes will become ____________ and the _____ of photosynthesis will __________ and ______.
Because photosynthesis is an enzyme controlled reaction, if the temperature increases too much, the enzymes will become [denatured] and the [rate] of photosynthesis will [decrease] and [stop].
the rate of photosynthesis [increases/decreases] with light intensity [to a point/forever].
the rate of photosynthesis [increases] with light intensity [to a point].
uses of glucose 1: to produce ________ which strengthens cell walls.
uses of glucose 1: to produce [cellulose] which strengthens cell walls.