Topic 4 - Bionergetics Flashcards
What is aerobic respiration?
A form of respiration that uses oxygen to release energy from molecules like glucose - represented by the following word equation:
Glucose + Oxygen = Carbon Dioxide + Water
What is Anaerobic Respiration?
A form of respiration that releases energy from molecules like glucose without using oxygen - represented by the following word equation:
Glucose = Lactic Acid
What is cellular respiration?
An exothermic reaction which is continuously occurring in living cells.
What is inverse square law?
As the distance from a light source increases, the light intensity is inversely proportional to the distance squared.
What is metabolism?
The sum of all the reactions in a cell or body.
What is oxygen debt?
The amount of extra oxygen in the body needs after exercise to react with the accumulated lactic acid and remove it form the cell.
What is photosynthesis?
An endothermic reaction in which energy is transferred from the environment to the chloroplasts by light.
Where does photosynthesis take place?
Within chloroplast in leaf palisade cells. They contain chlorophyll, a pigment which absorbs light energy.
How can you show that a plant gives off oxygen during photosynthesis?
Using a water plant (e.g. Elodea), collect gas bubbles produced during photosynthesis. The gas will relight a glowing splint as it contains oxygen.
Give examples of leaf adaptations which maximise the rate of photosynthesis?
- Broad Leaves to maximise surface area.
- Thin leaves for short diffusion distance.
- Chlorophyll present to trap light energy.
- Veins to transport water to leaves via xylem, remove photosynthesis products via phloem.
- Air space allow CO2 to enter and O2 to leave.
- Guard cells control opening of stomata for gas exchange but they also prevent water loss.
Four factors that affect photosynthesis?
- Temperature
- Light Intensity
- Carbon Dioxide Concentration
- Amount of Chlorophyll
How does temperature affect the rate of photosynthesis?
Increasing the temperature increases the rate of photosynthesis as the kinetic energy of particles is increase. The rate increase or past a certain temperature the enzyme will denature.
How does carbon dioxide concentration affect the rate of photosynthesis?
Increasing the carbon dioxide concentration increases the rate of photosynthesis as CO2 is required to make glucose.
What is a limiting factor?
An environmental factor which can restrict the rate of photosynthesis e.g. light intensity.
How can farmers use their knowledge of limiting factors to increase their profits?
They can control temperature, light intensity and CO2 concentration to achieve the fastest possible rate of photosynthesis, leading to a greater yield.
What are 5 uses of glucose that is produced in photosynthesis?
- Respiration
- Starch for storage
- Cellulose for strength
- Amino acid and protein synthesis.
- Lipids for energy storage in seeds.
Where does aerobic respiration take place?
In the mitochondria.
Why do organisms require the energy released by respiration?
- Synthesis of larger molecules
- Muscles contraction
- Maintenance of body temperature
- Active transport
What is fermentation?
A type of anaerobic respiration that occurs in yeast cells.
The equation for fermentation?
Glucose = ethanol + carbon dioxide (+ energy)
Why is the fermentation reaction important?
It is used in the production of bread alcoholic drinks.
How do muscles store glucose?
As glycogen.
How is lactic acid transported away from the muscles?
Blood flow through the muscles transports lactic acid to the liver, where it is oxidised back to glucose.
What is Glucagon?
Glucagon is a natural hormone produced by the pancreas. It works with other hormones and bodily functions to control glucose (sugar) levels in your blood. Glucagon prevents blood sugar from dropping too low.
