Topic 4: Bioenergetics Flashcards
Photosynthesis word and symbol equation?
carbon dioxide + water —-> glucose + oxygen
6CO2 + 6H2O —-> C6H12O6 + 6O2
How do plants use glucose?
For respiration
Making cellulose
Making amino acids - combined with nitrate ions to make aa, then made into proteins
Stored as oils or fats - turned into lipids for storing in seeds
Stored as starch - and stored in roots, stems and leaves ready for when photosynthesis isn’t happening - in winter
Limiting factors of photosynthesis?
Light Intensity
Temperature
CO2 Concentration
[Amount of chlorophyll]
Graphing limiting factors?
Both the CO2 and light intensity graphs remain constant at a certain point, whereas the temperature graph goes up then down, as the enzymes needed for photosynthesis will denature at about 45oC
Photosynthesis RP?
Canadian pondweed can be used to measure the effect of light intensity on the rate of photosynthesis.
A source of white light is placed at a specific distance from the pondweed
Count the bubbles produced
And repeat at different distances
How to measure light intensity?
Use 1/d^2 when d is the distance
How to artificially create ideal conditions?
Greenhouses help to trap the sun’s heat and they ensure that temp does not become a limiting factor.
Farmers often use lamps to ensure that light intensity does not become a limiting factor.
They also increase the CO2 concentration by using a paraffin heater to heat the greenhouses.
Keeping plants enclosed in greenhouses also ensures that pests and diseases are kept out,
Respiration is the…?
The process of TRANSFERRING ENERGY FROM GLUCOSE, which goes on in EVERY CELL.
How do organisms use energy provided by respiration?
To build up larger molecules from smaller ones (like proteins from amino acids)
In animals, it’s used to allow the muscles to contract (for movement)
In mammals and birds, the energy is used to keep their body temperature steady in colder surroundings
Metabolism is the…?
Sum of all the reactions that happen in a cell or in the body.
Aerobic respiration equation and info?
Glucose + Oxygen —-> Carbon Dioxide + Water
C6H12O6 + 6O2 —-> 6CO2 + 6H2O
The most efficient way to transfer energy from glucose
Most of the reactions inside the mitochondria come from Aerobic respiration.
Anaerobic respiration equation and info?
Glucose —-> Lactic acid
C6H12O6 —-> 2C3H6O3
The incomplete breakdown of glucose
Doesn’t release nearly as much energy as aerobic respiration because the glucose is not fully oxidised
Anaerobic respiration in plants and yeast equation and info?
Glucose —-> ethanol + carbon dioxide
C6H12O6 —-> C2H5OH + 2CO2
In yeast cells = Fermentation
In the food and drinks industry, used to make bread and alcoholic drinks
IN bread-making, the CO2 makes bread rise
And in beer and wine-making, the fermentation process produces alcohol
When you exercise you…?
Respire more
The breathing rate and breath volume increase to get more oxygen into the blood, and your heart rate increases to get this oxygenated blood around the body faster, removing CO2 more quickly too.
When you do really vigorous exercise your body cannot supply enough oxygen to your muscles quickly enough, so they start respiring anaerobically.
Not the best way to transfer energy from glucose because the lactic acid produced builds up in the muscles and gets painful
What is oxygen debt?
It’s the amount of extra oxygen your body needs to react with the build-up of lactic acid and remove it from the cells. Oxygen will react with lactic acid to form harmless CO2 and water.
The pulse and breathing rate stay high whilst there are high levels of lactic acid and CO2.
Another way your body has of coping with high levels of lactic acid is by transporting it to the liver, where it is converted back to glucose
