B4: Bioenergetics Flashcards
What is the word equation for photosynthesis?
Carbon Dioxide + Water > Glucose + Oxygen
What is the balanced symbol equation for photosynthesis?
6CO2 + 6H2O > C6H12O6 + 602
Why is photosynthesis important for the survival of plants?
Because it allows plants to produce glucose, which can be broken down in respiration into energy needed for processes such as protein synthesis and cell division.
Why should plants be de-starched before photosynthesis experiments?
So you know that any starch present at the end of the experiment has been produced during the experiment.
How do you de-starch a plant?
By placing it in the dark for 48 hours.
How do you find out if a leaf contains starch?
Using an iodine starch test. (See RPA)
What are the limiting factors of photosynthesis?
- Low temperature.
- Shortage of CO2.
- Shortage of light.
- Shortage of chlorophyll.
What are the 4 ways in which conditions of a greenhouse can be optimised for plant growth?
To create the optimum conditions for photosynthesis,
- The temperature can be controlled with heaters (expensive).
- The amount of carbon dioxide can be monitored.
- The amount of light can be controlled using UV lamps.
- The amount of chlorophyll can be increased by using nutrient-rich soil.
What are the benefits of artificially manipulating plant growth?
Faster growth and increased yield lead to more profit.
What is the glucose produced in photosynthesis used for?
- Respiration.
- Converted into starch for storage.
- To produce cellulose to strengthen cell walls.
- To produce amino acids for protein synthesis.
What are nitrates used for in plants?
To make proteins.
Food tests: what solution is used to test for starch?
Iodine Solution.
Food tests: what solution is used to test for protein?
Buiret Solution.
Food tests: what solution is used to test for sugars?
Benedict’s Solution.
What is the word equation for aerobic respiration in animals?
Glucose + Oxygen > Carbon Dioxide + Water.
What is the balanced symbol equation for aerobic respiration in animals?
C6H12O6 + 6O2 → 6CO2 + 6H2O.
Is respiration an endothermic or exothermic reaction?
Exothermic. (Releases energy)
Is photosynthesis an endothermic or exothermic reaction?
Endothermic. (Takes IN light energy)
What is aerobic respiration?
Respiration using sufficient oxygen.
What 3 things do organisms need the energy from respiration for?
- Chemical reactions.
- Movement.
- Keeping warm.
What is anaerobic respiration?
Respiration using insufficient oxygen.
What is the word equation for anaerobic respiration in animals?
Glucose > Lactic Acid.
What is the balanced symbol equation for anaerobic respiration in animals?
C6H12O6 > 2C3H6O3.
What are the products of anaerobic respiration in animals vs plants/yeast?
Animals: Lactic Acid.
Plants/Yeast: Ethanol + Carbon Dioxide.
What are the consequences of anaerobic respiration?
Much less energy is released than aerobic respiration.
What is the word equation for anaerobic respiration in plants/yeast cells?
Glucose > Ethanol + Carbon Dioxide.
What is the balanced symbol equation for anaerobic respiration in plants/yeast cells?
C6H12O6 > 2C2H5OH + 2CO2
What is anaerobic respiration in yeast cells called?
Fermentation.
Which industries is fermentation used in?
The manufacture of bread and alcoholic drinks.
Why is anaerobic respiration of yeast used to make bread and alcoholic drinks?
- The bubbles of carbon dioxide produced make bread rise.
- The ethanol produced creates alcohols.
What happens to heart and breathing rates during exercise?
They increase.
Why do heart and breathing rates increase during exercise?
To supply oxygen to muscle cells faster.
What happens when there isn’t enough oxygen in the muscles?
They respire anaerobically and produce lactic acid.
What is oxygen debt?
The amount of oxygen needed to oxidise the lactic acid in the body.
What happens to breath volume during exercise?
It increases.
How does the body get rid of lactic acid?
Blood transports lactic acid to the liver where it is converted back into glucose.
What does lactic acid cause in muscles?
Muscle fatigue.
What is metabolism?
The rate of chemical reactions in the body.
Give 3 examples of metabolic reactions in the body.
the conversion of glucose to starch, glycogen and cellulose
the formation of lipids
the formation of amino-acids and proteins
respiration
the breakdown of excess proteins to form urea for excretion.
Describe the formation of urea.
Urea is produced from the breakdown of excess protein/amino acids in the liver.
What are glucose and nitrate ions used to do in animals?
Create amino acids that are used to make proteins.
