BIoenergetics Flashcards
What is the suns energy used for in plants?
To make food
What does the plant manufacture glucose from?
The plant manufactures glucose from carbon dioxide and water using energy transferred from the environment to the chloroplasts by light
Is photosynthesis endothermic or exothermic?
This is an endothermic reaction because photosynthesis needs an input of energy from the environment.
What is the word equation for photosynthesis?
Carbon dioxide + water –(light)–> glucose + oxygen
Symbol equation for photosynthesis?
6CO2 + 6H2O –(light)–> C6H12O6 + 6O2
What type of reaction is photosynthesis?
An enzyme controlled reaction.
Limiting factors for photosynthesis?
Carbon dioxide concentration, temperature, light intensity.
What are the uses for the glucose made from photosynthesis?
- To produce cellulose which strengthens plant cell walls.
- To be converted into insoluble starch for storage inside cells or special areas like roots or bulbs.
3.To be converted into amino acids for protein synthesis.
Glucose is combined with nitrate ions absorbed from the soil. Specific amino acids join in long chains to make a named protein. - To produce fat or oil for storage.
Seeds and nuts contain lots of fat or oil as an energy store.
What is the definition of a limiting factor?
A factor which is not at an optimum level to enable maximum rate of photosynthesis e.g. temperature
Name the raw materials needed by a plant for photosynthesis?
Carbon dioxide and water
Name the green pigment present in plant cells.
Chlorophyll
What is the role of chlorophyll?
To transfer energy from the environment and use it to synthesise glucose from carbon dioxide and water.
Is respiration endothermic or exothermic?
Respiration is an exothermic reaction which means energy is transferred to the environment. Some of the energy is used inside cells and the rest will be transferred out of the cell.
Why do living organisms need energy?
- For movement. To enable muscles to contract in animals.
- For keeping warm. To keep a steady body temperature in a cold environment.
- For chemical reactions. To build larger molecules from smaller ones.
Word equation for aerobic respiration in humans
glucose + oxygen —-> energy + carbon dioxide
Symbol equation for aerobic respiration in humans
C6H12O6 + 6O2 —–> 6CO2 + 6H2O
Where does aerobic respiration occur?
Inside mitochondria
Anaerobic respiration equation in humans
glucose —> lactic acid
Anaerobic respiration is plants equation
glucose ——> ethanol + carbon dioxide
When does respiration occur in cells?
Continuous
Why is fermentation of economic importance?
Used in the manufacture of bread and alcoholic drinks.
Describe three ways in which the body responds to vigorous exercise in order to ensure sufficient oxygen reaches the muscle cells
Increase in heart rate; increase in breathing rate and increase in breath volume.
If exercise carries on for a long time, what happens to the muscles?
Muscles become fatigued and stop contracting efficiently.
What are carbohydrates made from?
Many glucose molecules
What are lipids made from?
1 molecule of glycerol and 3 molecules of fatty acid
What is protein made from?:
Many amino acids
What is metabolism?
Metabolism is the sum of all reactions which occur in a cell or body.
Describe the process for removing lactic acid from the body.
Blood flows through the muscle cells and transports the lactic acid to the liver where it is converted back into glucose. The glucose is then used in aerobic respiration or stored as glycogen.
What is meant by the oxygen debt?
The amount of extra oxygen which is needed to remove all lactic acid from the body is known as the oxygen debt.
