Photosynthesis Flashcards
What is the balanced equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
What is the word equation for photosynthesis?
Carbon Dioxide + Water → Glucose + Oxygen
For the reaction to occur, chlorophyll and light energy are required
What raw materials are necessary for photosynthesis to occur?
- Water
- Carbon Dioxide
- Minerals
- Chlorophyll
Name 6 ways in which plants use glucose
- Stored as insoluble starch
- Transported as sucrose to rest of plant
- Respiration to provide energy
- Building cell walls (cellulose is a glucose polymer)
- Converted to lipids for long term energy storage
- Converted to amino acids using minerals such as nitrates absorbed from the soil to make proteins
Why is glucose stored as starch in the plant?
Because strach is insoluble so it will stay in the leaf while glucose can dissolve and be transported elsewhere
Why is photosynthesis important for plant growth?
Glucose is broken down to release energy for protein synthesis and the carbon compound in glucose is used to sythesise amino acids and then protein
What is light energy used for in photosynthesis?
It is used by chlorophyll to break down the reactants
What is light used for in photosynthesis?
Light is transferred by chlorophyll as chemical energy to drive the reactions that form carbohydrates from water and carbon dioxide.
Does photosynthesis use enzymes?
Yes
All bodily chemical reactions use enzymes
What are the main limiting factors in Photosynthesis?
- Light intensity
- Temperature
- Availability of Carbon Dioxide
Why are chloroplasts, water and ions not really limiting factors for photosynthesis?
- There is not normally a deficiency of water or ions in the soil compared to the 0.04% concentration of Carbon Dioxide in the air
- Chloroplasts are made from water and ions
How does temperature affect the rate of photosynthesis?
As the temperature increases, the rate of photosynthesis increases, until the optimum peak, after which the enzymes used in the reaction denature and cease to function.
Photosynthesis stops at approximately 45 degrees
How does carbon dioxide concentration in the air affect the rate of photosynthesis?
As the concentration of Carbon Dioxide increases, the rate of reaction will increase until it plateaus due to another of the photosynthesis limiting factors is limited e.g. Light Intensity/Temperature.
How does light intensity the affect rate of photosynthesis?
As the the intensity of light increases, the rate of reaction will increase until it plateaus due to another of the photosynthesis limiting factors is limited e.g. Carbon Dioxide Concentration/Temperature.
What are the parts of the leaf sructure?
Name them in order from the top to the bottom
- Waxy cuticle
- Upper epidermis
- Palisade mesophyll
- Vascular bundle (Xylem & Phloem)
- Spongy mesophyll
- Air spaces
- Lower epidermis
- Stomata
- Guard cell
- Waxy cuticle
Which layers of the leaf contain chloroplasts?
The Mesophyll Layer
- Palisade mesophyll
- Spongy mesophyll
What is the purpose of the waxy cuticle?
To retain water and reduce water loss
Why is Phosphate needed for the plant?
Making DNA and Cell Membranes
Why is magnesium needed for the plant?
Used in making chlorophyll
Why are nitrates needed for plants?
Required to make amino acids, and therefore protein
What is the result in a plant due to a phospate deficiency?
Leaves turn partially purple
What is the result in a plants due to a magnesium deficiency?
Yellowing of the leaves betwen the veins
What is the result in plants due to nitrate deficiency?
Yellowing of leaves and stunted growth
What is the structure of the Xylem?
- They are hollow cylindrical tubes that pull up water from the roots
- Xylem is made of dead cells (only the cell wall remains)
- Walls strengthened with cellulose and waterproofed with lignin
What is the structure of the Phloem?
- Elongated tubular cells with walls between them
- Phloem cells are living
- Sieve structures between each companion cell
What is the purpose of the Xylem?
To transport water and minerals upwards through the plant to the leaves
What is the purpose of the Phloem?
To transport Sugars up and down the plant
