Topic 4 - Bioenergetics Flashcards
What is the equation for photosynthesis?
Carbon dioxide + water –light–> glucose + oxygen
What is the symbol for carbon dioxide in the photosynthesis equation?
6 CO2
What is the symbol for water in the photosynthesis equation?
6 H2O
What is the symbol for glucose in the photosynthesis equation?
C6H12O6
What is the symbol for oxygen in the photosynthesis equation?
6O2
What is photosynthesis?
An endothermic reaction in which energy is transferred from the environment to the chloroplasts by light
What are the four limiting factors of photosynthesis?
Light intensity
Amount of chlorophyll
Temperature
Concentration of CO2
What is a limiting factor?
A factor stopping photosynthesis from happening any faster
What factors are limiting at night?
Light intensity
What factors are limiting in the winter?
Temperature
When is CO2 a limiting factor?
If it’s warm enough and bright enough
How is chlorophyll a limiting factor?
The amount of chlorophyll can be affected by disease or environmental stress (lack of nutrients) which damage chloroplasts and cause them to not make enough chlorophyll so they can’t absorb as much light
What is the inverse square law?
Distance squared and light intensity are inversely proportional
What is the equation for the inverse square law?
Light intensity = k / distance (squared)
How do you artificially create the ideal conditions for farming?
Using a greenhouse
How do greenhouses work?
They trap the suns heat and make sure temperature doesn’t become limiting
How does a farmer keep the ideal conditions while still making a profit?
If the conditions are just right, the plant will grow faster and be a decent crop to be harvested more often and therefore more can be sold from one plant otherwise they will waste money
What is glucose in plants used for?
- respiration
- converted to insoluble starch for storage
- produce fat or oil for storage
- produce cellulose to strengthen cell wall
- produce amino acids doe protein synthesis
What is respiration?
The process of transferring energy from glucose which goes in every cell
Is respiration endothermic or exothermic?
Exothermic - it transfers energy to the environment
What does respiration transfer energy for?
Chemical reactions to build larger molecules
Movement
Keeping warm
What is aerobic respiration?
Respiration using oxygen
What is anaerobic respiration?
Without oxygen
Where does aerobic respiration happen?
Mitochondria
What is the equation for aerobic respiration?
Glucose + oxygen —-> carbon dioxide + water
What is the symbol equation for aerobic respiration?
C6H12O6 + 6O2 —-> 6CO2 + 6H2O
What is the equation for anaerobic respiration? (In animals)
Glucose —-> lactic acid
What is the equation for anaerobic respiration? (In plants and yeast)
Glucose —-> ethanol + carbon dioxide
Why is less energy transferred in anaerobic respiration?
The oxidation of glucose is incomplete
What is anaerobic respiration in heats cells called?
Fermentation
When is fermentation used in industry?
To make bread and alcoholic drinks
What happens during exercise?
The human body reacts to the increased demand for energy
What increases during exercise to supply the muscles with more oxygenated blood?
Heart rate
Breathing rate
Breath volume
What happens if there is an insufficient supply of oxygen?
Anaerobic respiration happens in the muscles
What does the incomplete oxidation of glucose cause?
Lactic acid to build up and oxygen debt
What happens in long periods of vigorous exercise?
Muscles become fatigues and stop contracting efficiently
What transports lactic acid away from the muscles and where to?
Blood transports it to the liver where it is converted back to glucose
What is oxygen debt?
The amount of extra oxygen the body needs after exercise to react with the lactic acid and remove it form cells
What is metabolism?
The sum of all the chemical reactions in an organism
What is the energy used for in cells?
Continual enzyme controlled processes of metabolism that synthesise new molecules
What does metabolism do?
- converts glucose to starch, glycogen and cellulose
- forms lipid molecules from 1x glycerol and 3x fatty acids
- uses glucose and nitrate ions to form amino acids which synthesises proteins
- respiration
- breakdown excess proteins from urea for excretion
