B4-Bioenergetics Flashcards
What is photosynthesis?
An endothermic reaction in which energy is transferred to chloroplasts from the environment by light
What is the word equation for photosynthesis?
Carbon dioxide+water➡️glucose+oxygen
What is the number equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2.
1)What is one use of glucose in plants?
Respiration-Energy is transferred from glucose
2)What is another use of glucose in plants?
Strengthening cell walls- glucose is converted into cellulose, which is used to make stong cell walls
3) What is another use of glucose in plants?
Protein synthesis- glucose and nitrate ions (from soil) are used to make amino acids, which are then made into proteins
4) What is the use of glucose in plants?
Energy storage- glucose is turned into lipids or insoluble starch to store energy
What is the inverse square law?
Links to light intensity with distance from a light source -light intensity ⍺ 1/distance² -e.g doubling the distance means light intensity is four times smaller
An increase in which four factors tends to increase the rate of photosynthesis?
Light intensity, temperature, co2 concentration and amount of chlorophyll.
These factors can become a limiting factor.
What is a limiting factor?
Stops photosynthesis happening any faster
Why is temperature a limiting factor?
High temperatures damage enzymes involved in photosynthesis
How can you control limiting factors in a greenhouse to maximise the rate of photosynthesis?
Ventilation, shades, lamps, heaters (paraffin ones for co2)
What is respiration?
The process of transferring energy from glucose. It’s an exothermic reaction that goes on continuously in living cells.
Examples of the energy transferred is used for all living processes?
- To contract muscles for movement
- To keep warm (in mammals and birds)
- To build up larger molecules from smaller ones
What is aerobic respiration?
Respiration using oxygen. It’s the most efficient type of respiration
What is the word equation for aerobic respiration?
Glucose + oxygen ➡️ carbon dioxide +water
What is Anaerobic respiration?
Respiration without oxygen. It transfers much less energy than aerobic respiration because glucose isn’t fully oxidised
Anaerobic respiration word equation in muscle cells?
Glucose➡️ lactic acid
Anaerobic respiration word equation in plant and yeast cells?
Glucose➡️ ethanol + carbon dioxide
In yeast cells what is anaerobic respiration called and what is the process used to make?
Fermentation, bread and alcoholic drinks
What is Metabolism?
The sum of all the reactions that happen in a single cell or the body.
Why does metabolic reactions use energy from respiration?
To make new molecules
What is made when glucose and nitrate ions are combined? (example of metabolic reactions use of energy from respiration to make new molecules)
Amino acids which are then made into proteins
What are lipids broken down into? (example of metabolic reactions use of energy from respiration to make new molecules)
Glycerol and fatty acids
What is made when when glucose molecules are joined together?(example of metabolic reactions use of energy from respiration to make new molecules)
Bigger carbohydrates (starch or glycogen)
What is needed more when you exercise?
More energy, aerobic respiration and oxygen is needed
Three things that increase to get more oxygen to your muscles?
- Heart rate
- Breathing rate
- Breath volume
What is caused by exercising for a long period of time?
Muscle fatigue- the muscles get tired and stop contracting efficiently
What is oxygen debt?
The amount of extra oxygen needed to react with built-up lactic acid and remove it from cells.
What happens to the muscles when not enough oxygen is supplied during vigorous exercise?
- Anaerobic respiration takes place in muscles
- Lactic acid builds up in muscles
3.oxygen debt is created - Heart rate and breathing rate stay high after exercise to replay oxygen debt
How does the liver help deal with lactic acid?
oxidised to carbon dioxide and water, or. converted to glucose, then glycogen - glycogen levels in the liver and muscles can then be restored.
