Topic 4//Photosynthesis/Respiration/Metabolism/Aerobic/Anaerobic/Exercise Flashcards
What is word equation for photosynthesis
carbon dioxide + water =
glucose + oxygen
What are the 5 ways plants use glucose
Respiration
Making cellulose
Making amino acids
Stored as fats or oil
Stored as starch
How do plants use glucose for respiration
Respiration transfers energy from glucose which enables plants to convert rest of glucose into various useful substances
How do plants use glucose for Making cellulose
Glucose is converted into cellulose for making strong plant cell walls
How do plants use glucose for Making amino acids
Glucose is combined with nitrate ions to make amino acids which are then made into proteins
How do plants use glucose for storing as fats or oil
Glucose is turned into lipids for storing in seeds
How do plants use glucose for storing as starch
Glucose is turned into starch and stored in roots, stems and leaves ready for use when photosynthesis isnt happening like in winter.
Starch is insoluble which makes it better than storing as glucose
What main 2 factors limits rate of photosynthesis depending on environmental conditions
At night - Light is limiting factor
In winter - Temperature is limiting factor
How does light slow down rate if photosynthesis
Light provides energy needed for photosynthesis. As light level is raised, rate of photosynthesis increases steadily only to a certain point. Beyond that as light intensity increases, rate will no longer increase as either CO2 or temp is limiting factor
How does CO2 affect rate of photosynthesis
Amount of CO2 will only increase rate of photosynthesis up to a point. Beyond that point, the limiting facot must be either temperature or light
How does Temperature affect rate of reaction
Usually if temperature is limiting factor its because its too low and enzymes needed for photosynthesis work more slowly . If plant gets too hot, the enzymes needed for photosynthesis will get damaged
What are the 6 steps of Measuring rate of photosynthesis
- source of light placed at specific distance from pondweed
- then left to photosynthesise for set amount of time whilst O2 will be collected in capillary tube
- syringe is used to draw gas bubbles in tube alongside ruler and length is measured
- experiment is repeated twice with same distance and mean volume of O2 calculated
- whole experiment repeated with light source at different distance
Define respiration
process of transferring energy from glucose which goes in every cell
Is respiration endo or exothermic
Exothermic - transfers energy to environment
What are the three examples of how organisms use energy transferred by respiration
- Build up larger molecules from smaller ones
- In animals, used to allow muscles to contract so can move about
- In mammals and birds, energy is used to keep their body temperature steady in colder surroundings
Define Metabolism
The sum of all of the reactions that happens in a cell or the body
What is aerobic respiration
Respiration using oxygen and is most efficient way to transfer energy from glucose in plants and animals. Most reactions happens in mitochondria.
What is formula for aerobic respiration
glucose + oxygen=carbon dioxide + water
What is anaerobic respiration
incomplete breakdown of glucose making lactic acid and it doesnt transfer as much energy as aerobic respiration because oxygen is not fully oxidised.
What is formula for anaerobic respiration in humans
Glucose = lactic acid
Describe Anaerobic respiration in yeast cells
They can respire without oxygen and in yeast cells is called fermentation which is used to make bread ( its the Co2 that makes the bread rise) and alcoholic drinks
What is work equation if Anaerobic respiration in plants and yeast cells
Glucose = ethanol + carbon dioxide
How does Anaerobic respiration lead to an Oxygen Debt
When you stop exercising, you will have to repay the oxygen that you didnt get to your muscles in time because your heart, lungs and blood couldnt keep up with the demand earlier so you have to keep breathing hard to get more oxygen into your blood.
How does your body cope with high levels of lactic acid
the blood that enters your muscles transport lactic acid to the liver when it is converted back to glucose
Define oxygen debt
Amount of oxygen your body needs to react with the build up of lactic acid and remove it from cells.
So oxygen reacts with lactic acid to form harmless carbon dioxide and water
