Photosynthesis & Limiting factors

Question 1

What is photosynthesis

Answer 1

• The process by which pants use the suns light, along with carbin dioxide and water, to produce glucose, and oxygen

Question 2

What is the word equation for photosynthesis

Answer 2

Water + Carbon Dioxide —-> Glucose + Oxygen

Question 3

What is the symbol equation for photsynthesis

Answer 3

6H2O + 6CO2 —-> C6H12O6 + 6O2

Question 4

Where does photosynthesis take place

Answer 4

• Takes place in the palisade mesophyllcells in the leaf
• They contain many chlorpolasts which contain a green igment called chlorophyll that captures sunlight

Question 5

How do the PM cells get there required reactants

Answer 5

• They get the CO2 via the air, as it diffuses in through the stomata
• They get the water via the xyem cells which bring water from the roots which is draw up from the soil via osmosis

Question 6

5 main uses of glucose

Answer 6

• Cellular respiration - takes place when photosynthesis can’t (at night / in winter). Breaks glucose to release energy that is used in cellular respiration
• Making amino acids - glucose can be combined with nitrate ions to form amino acids. These can be joined together to form proteins
• Making cellulose - is used to strengthen cell walls
• Storage via starch - can be made into starch for long - term storage. Sarch is more compact and insoluble (water will no be drawn in via osmosis)
• Storage via fats & oils - can be made into lipids for long - term storage, usually in seeds

Question 7

Limiting factors of photosynthesis

Answer 7

• Light intensity (at night)
• Temperature (winter)
• CO2 concentration
• Amount of chlorphyll

Question 8

What is the graph for how Light Intensity affects the rate of photosynthesis

Answer 8

• As light intensity increases, the rate of photosynthesis also increases as the cells have more energy to carry out photosynthesis
• ROP only increases up to a certain point after which the graph plateaus as another factor is limiting the ROP

Question 9

What is the graph for how CO2 concentration affects rate of photosynthesis

Answer 9

• As CO2 concentration increases, the rate of photosynthesis also increases up to a certain point
• After this poits, the graph plateaus as another factor is limiting the ROP

Question 10

What is the graph for how temperature affects rate of photosynthesis

Answer 10

• As temperature increases, ROP increases slowly
• After a certain points, ROP starts to decrease as a enzyme becomes denatured

Question 11

At what temperature do enzyes denature (photosynthesis)

Answer 11

• Around 45 C

Question 12

How does chlorophyll affect rate of photosynthesis

Answer 12

• The amouunt of chlorophyll affects the amount of light the cells can absorb, which inturn affects the ROP
• The amount of chlorophyll can be affected by: disease (TMV) or environmental stress

Question 13

How can artificial conditions be created by farmers

Answer 13

• Farmers can replicate the perfect conditions via a few different methods:
• Greenhouse - captures and traps sunlight and heat
• Burning paraffin - releases CO2 and heat
• Artificial light source - allows cells to continue photosynthesis after the sun goes down (at night)

Question 14

What is the inverse square law

Answer 14

Light intensity is proportional to 1 / (distance)^2