Topic 4: Bioenergetics Flashcards
What is the equation for Photosynthesis?
Carbon Dioxide + Water –> Glucose + Oxygen
What is the balanced symbol equation for photosynthesis?
6 CO2 + 6H2O –> C6H12O6 + 6O2
What is an exothermic reaction?
Releases energy into surroundings
What is an endothermic reaction?
Takes in energy from surroundings
What type of reaction is photosynthesi?
Endothermic
What is glucose used for in respiration?
Provide energy
Where is light energy provided for photosynthesis?
Absorbed by chlorophyll
Where is water provided for photosynthesis?
Taken into roots by osmosis
Where is carbon dioxide provided for photosynthesis?
Enters leave in diffusion through stomata
Where is oxygen provided for respiration?
Leaves through diffusion by stomata in leaves
What is the inverse square law?
Light Intensity = 1/d^2
Less photons per mm so light intensity decreases as area increases
What are the uses of glucose?
- Respiration
- Converted into insoluble starch for storage
- Used to produce fat or oil for storage
- Used to produce cellulose, strengthens cell wall
- Used to produce amino acids for protein synthesis
- Control of osmosis
- Growth
- Make larger molecules
What are the limiting factors for photosynthesis?
- Temperature
- CO2 Concentration
-Light Intensity - Number of chlorophyll
- Volume of Water *only use if necessary
Why are limiting factors important?
Important in the economics of enhancing the conditions in greenhouses to gain the maximum rate of photosynthesis whilst maintaining profit
How can you read graphs and locate limiting factors?
The rate of photosynthesis will increase as limiting factor increases but will level out at point another factor prevents further increase of photosynthesis
Check flashcards for graphs
How can you read a temperature graph in relation to rate of photosynthesis?
The rate of photosynthesis will increase as temp. increases until optimum temp. is reached. The rate will then decreased as temp. increase further. This is because enzyme would have denatured.
Check flashcards for graphs
What is the starch food test?
- Food on white dimple tile
- Few drops of iodine solution
- Note colour change
- Starch turns iodine blue - black
What is the glucose food test?
- Grind food in pestle and mortar
- Two spatulas in test tube
- 1cm^3 of distilled water
- 10 drops of Benedict’s
- 80°C Water Bath for 5 minutes
- Turns brick red if present but varies due to sugar concentration
What is the protein food test?
- Grind food in pestle and mortar
- Two spatulas in test tube
- 1cm^3 of distilled water
- 10 drops of Biuret’s and Sodium Hydroxide
- Shake
- Protein turns purple
What are guard cells?
Use osmotic pressure to open and close stomata, allowing plants to regulate water ( prevent water loss ) and facilitate gas exchange necessary for photosynthesis
What are palisade cells?
Receive most sunlight for the production of glucose and oxygen in photosynthesis, contain most chloroplasts and are closely packed together to increase rate of absorption
What is the independent variable?
Variable which is altered
What is the dependent variable?
Variable being tested for
What is the control variable?
Variable being maintainedWhat
What do plants use to produce proteins?
Plants use nitrate ions that are absorbed by soil
What is respiration?
Exothermic reaction naturally and continuously occurring in living cells
What is respiration needed for?
- Movement
- Building of larger molecules (growth)
- Maintaining body temperature
What is the equation for aerobic respiration?
Glucose + Oxygen –> Carbon Dioxide + Water
C6H12O6 + 6O2 –> 6CO2 + 6H2O
What is anaerobic respiration?
Incomplete reaction with the production of lactic acid
What is the equation for anaerobic respiration in animals?
Glucose –> Lactic Acid
What is lactic acid?
Toxic substance created in anaerobic respiration by product of incomplete breakdown of glucose. Enters blood and liver and is broken back down to glucose with oxygen
What is the equation for anaerobic respiration in yeast / plants?
Glucose –> Ethanol + Carbon Dioxide
What is anaerobic respiration of yeast also known as?
- Fermentation
- Always produces Alcohol
- Used to create alcohol as well as making bread
How does the body respond to exercise?
- Body reacts to increased demand for energy
- Heart + Breathing Rate increases to supply muscles with more oxygenated that is needed for increased cellular respiration to transfer more energy to meet demand
What is oxygen debt?
Volume of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove from cells
What is muscle fatigue?
- When muscles are subjected to long periods of vigorous activity, they become fatigued i.e. stop contracting efficiently
- If insufficient amount of O2 reaching muscles. they use anaerobic respiration to obtain energy
What is metabolism?
Sum of all chemical reaction in organism
What does metabolism allow organisms to do?
- Grow
- Respond to environment
- Reproduce
- Maintain Structure
What does metabolism include?
- Conversion of glucose to starch, glycogen and cellulose
- Formation of lipid molecules
- Use of glucose to form amino acids
- Respiration
- Breakdown of excess proteins to form urea for excretion
