Bioenergetics 🌿 Flashcards
What do plants use light for ?
Energy
What is photosynthesis?
When plant traps light and transfers it to energy
What type of chemical reaction is Photosynthesis?
ENDOTHERMIC - takes in energy
Where does photosynthesis take place ?
The leaves ! - contain chlorophyll- absorbs energy found to the chloroplasts
What is the word and Symbol equation for photosynthesis?
Sunlight
Carbon dioxide + water ~> oxygen+glucose
Chlorophyll
6Co2 + 6h2O ~> 6O2 + C6H12O6
What increases the rate of photosynthesis?
Light intensity- photosynthesis can happen faster - LIMITING- if it’s not fast enough - not enough light 
What kind of factor is light intensity for photosynthesis?
LIMITING - not enough photosynthesis? - light
What are the uses of glucose released by photosynthesis?
To release energy in respiration. In the mitochondria
Is to produce insoluble storage Made of starch so that plants can photosynthesis at night- Can be converted back into glucose when it’s needed (night)
Converted into fats and oils- Storage form of energy
To make cellulose which is the part but that gives the plant cell strength
To produce amino acids used by the plant to synthesise proteins- Have to absorb nitrate ions from the soil
Explain the photosynthesis practical
Get a boiling tube and place it at 10 cm away from my LED source- Doesn’t release too much heat
Put the tube of sodium hydrogen carbonate solution-Releases carbon dioxide which is needed for photosynthesis
Put some pond weed in it with a cut end at the top
Leave it for five minutes to acclimatise to the conditions of the boiling tube
You’ll see bubbles being produced by the content of the pondweed this is oxygen produced by photosynthesis
Start a stopwatch and count the number of bubbles produced per minute
Repeat and calculate the mean number bubbles produced per minute
Do it with a variety of distance away from the LED source like 20 cm to 30 cm

What are the two main problems with the photosynthesis particle?
Bubbles can appear too quickly and too fast to count accurately
Bubbles are not always the same size
How do you get around the bubbles issuesIn the photosynthesis practical?
We put a funnel on top of the pond weed in a beaker and put a measuring cylinderFilled with water
Then we measured the measuring cylinder to see them out of oxygen gas has been produced volume
What happens if you double the distance of the LED source? What is this called?
The number of bubbles per minute falls by four
Inverse - square law
If we double the distance to light intensity Falls by four times
Causing the number of oxygen bubbles to fall four times
What are the four limiting factors?
Carbon dioxide
temperature
light intensity
chlorophyll
What is a limiting fActor?
Something that limits the rate of photosynthesis
If we increase the carbon dioxide in a graph and it stopped increasing the rate of photosynthesis what does this tell us?
That carbon dioxide is no longer the limiting reaction as there’s plenty of it available
How do you Farmers use greenhouses?
The add light and heat and add extra carbon dioxide  - use oil burners - Produce heat and carbon dioxide at the same time
How was the extra cost of greenhouses justified by farmers?
By the increase in yield
Why do we need energy?
For movement
to keep warm and
for chemical reactions to build larger molecules
like lipid
proteins - Chemically joining amino acids
carbohydrates
What chemical reaction takes place to give us energy?
Respiration
What kind of chemical reaction is respiration?
Exothermic as it releases energy- Takes place continuously in living cells 
What is the word equation for aerobic respiration
Glucose+ oxygen~> carbon dioxide + water+ energy
How much energy does aerobic respiration release? why?
A great deal of energy
Because the glucose molecule has been fully oxidised
When does anaerobic respiration occur?
When there is a limit of oxygen
What is the word equation for anaerobic respiration?
Glucose -> lactic + acid energy
