Biology 8: Photosynthesis Flashcards
How does Carbon Dioxide concentration limit the rate of photosynthesis?
- As Carbon Dioxide concentration increases so does rate of photosynthesis
- Rate of photosynthesis then begins to level off on graph because of another limiting factor
- So further increase in Carbon Dioxide concentration has no affect
Is photosynthesis an exothermic or endothermic reaction and why?
-Endothermic reaction because energy is transferred from the environment to the chloroplast by light
How is a leaf adapted for photosynthesis?
- Large surface area
- Thin so diffusion distances are short
- Chlorophyll in chloroplasts to absorb light
- Veins bring water in xylem to cells and removes products in phloem
- Air spaces allow Carbon Dioxide to get to cells, and Oxygen to leave cells
- Guard cells open and close stomata to regulate gas exchange
How does the temperature limit the rate of photosynthesis?
- As temperature increases so does rate of photosynthesis because greater energy so more successful collisions
- Highest part on graph is optimum temp (usually 40-50C), this is ideal temp for enzymes to work so photosynthesis is at its fastest
- If temp gets to high the enzymes controlling photosynthesis will denature and rate of photosynthesis will fall
Benefits of hydroponics:
- Uses less space
- Faster crop time (greater production) so mcreates more profit
- More cost efficient
- Conservation of resources (water recycled)
- Less labour necessary
How do adaptations of the leaf make photosynthesis efficient?
-The leaf can photosynthesise as much as possible whenever there is light
What are the main uses of glucose?
- Respiration
- Storage for insoluble starch
- Storage in seeds
- Cellulose
- Protein synthesis
- Sucrose
What are the safety risks involved in the test for starch?
- Ethanol is highly flammable and harmful
- Always wear eye protection
- No naked flames- use a hot water bath to heat Ethanol
What process does using Glucose for Storage for insoluble starch involve/ how is it useful/ where does it take place?
- Converts soluble Glucose into insoluble starch for storage
- Useful for when photosynthesis isn’t happening (at night)
- Takes place in roots, stems and leafs of potato and carrot plants
What process does using Glucose for Sucrose involve/ how is it useful/ where does it take place?
- Glucose and Frutose are used to produce Sucrose for storing fruits
- Useful as fruits taste nice so animals eat them and spread seeds in their faeces
- Takes place in fruit
What are the main limiting facotrs that affect the rate of photosynthesis?
- Light intensity
- Temperature
- Carbon Dioxide concentration
- Amount of chlorophyll
Why is chorophyll needed for photosynthesis?
-Traps light energy required during photosynthesis
What process does using Glucose for Storage in seeds involve/ how is it useful/ where does it take place?
- Glucose produces lipids (fats and oils) for storing in seeds
- Useful as the seeds provide food from plant to respire
- Takes place in seeds
Photosynthesis word equation:
Carbon dioxide + Water —> Glucose + Oxygen
light written above arrow
Why do plants need light to carry out photosynthesis?
-To create glucose, which they store for later use as energy
How is algae adapted for photosynthesis in water?
- A large surface area
- They absorb Carbon Dioxide dissolved in water around them
- They oxygen they produce dissolves into water aound them as it is released
What process does using Glucose for Protein synthesis involve/ how is it useful/ where does it take place?
- Glucose and Nitrate produce amnio acids for protein synthesis
- Useful as protein synthesis helps sustain the plant for its first few days and produces enzymes
- Takes place in ribosomes
How does light intensity limit the rate of photosynthesis?
- As light intensity increases so does rate of photosynthesis
- Rate of photosynthesis then begins to level off on graph because of another limiting factor
- So further increases in light have no affect
How are carnivorous plants adapted to thier environment (nitrate-poor soil)?
-They obtain most nutrients from animals they catch (e.g. insects) the plant then produces enzymes to digest the insects they trap
What are the main differences between a garden greenhouse and a hydroponics growing system?
- Hyproponics is growing a plant wothout soil while garden greenhouse uses soil
- Hydroponics uses mineral nutrient solutions (fertilisers) thats can be added through the watering system or directly to the plant while a garden greenhouse does not use fertilisers
How do plants make proteins?
- Use some of the Glucose from photosynthesis to make amino acids. They combine sugars with nitrate ions and other minerals from the soil
- These amino acids are then built up into proteins
Define photosynthesis:
-Process by which green plants and other organisms use sunlight to synthesize nutrients from Carbon Dioxide and Water
What process does using Glucose for respiration involved and how is it useful to the plant/ where does it take place?
- Glucose and Oxygen are used to produce Carbon Dioxide and Water
- Allows plant to convert rest of Glucose into another useful substance that can build new cells
- Takes place in mitochondria in the cells
Photosynthesis symbol equation (already balanced):
6CO2 + 6H2O —-> C6H12O6 + 6O2
How does chlorophyll levels in a plant limit the rate of photosynthesis?
- If a plant does not have enough minerals, especially magnesium, it cannot make chlorophyll so rate of photosynthesis will drop and plant will die
- As chlorophyll levels increase so does rate of photosynthesis
Where can starch be stored in plants?
- In the cells of the leaves.
- It provides energy for when it is dark or when light levels are low
- Many plants produce tubers and bulbs full of starch to survive through winter (potatos, onions)
- In the roots, stem and leaves
What process does using Glucose for Cellulose involve/ how is it useful/ where does it take place?
- Glucose is converted into Cellulose to strengthen cell walls
- Useful as they allow plant to grow tall and support the plant
- Takes place in cell wall
