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[h] iGCSE Biology Notes Plant nutrition
[q] How do plants get glucose?
Where do plants get glucose from?
[a]
- Glucose is a major energy store in all organisms.
- Bacteria, fungi and animals get glucose by consuming other organisms, but where do plants get it from?
- Plants carry out photosynthesis, where they harness the energy in sunlight to help produce glucose.
[q] How do plants get glucose?
Where do plants get glucose from?
[a]
- Photosynthesis is the process by which plants manufacture carbohydrates from raw materials using energy from light.
- Chlorophyll, a pigment inside chloroplasts is responsible for absorbing light energy and transferring it to chemical energy for synthesising carbohydrates
[q] What are limiting factors?
How can we make photosynthesis better?
[a]
- What is a limiting factor? § A limiting factor is something in limited amount and is therefore limiting the rate of a reaction
- What things are required for photosynthesis?
- Carbon dioxide, light and water (and chlorophyll)
- We’re going to talk about carbon dioxide, light intensity and temperature.
[q] How is carbon dioxide a limiting factor?
How can we make photosynthesis better?
[a]
- How does carbon dioxide concentration effect photosynthesis?
- The higher the concentration of carbon dioxide, the higher the rate of photosynthesis (while carbon dioxide is the limiting factor)
- The rate then plateaus because there is some other limiting factor.
[q] How is light intensity a limiting factor?
How can we make photosynthesis better?
[a]
- How does light intensity effect photosynthesis?
- The higher the light intensity, the higher the rate of photosynthesis (while light intensity is the limiting factor)
- The rate then plateaus because there is some other limiting factor.
[q] How is temperature a limiting factor?
How can we make photosynthesis better?
[a]
- How does temperature effect photosynthesis?
- The higher the temperature, the higher the rate of photosynthesis (while light temperature is the limiting factor)
- This is because particles have more kinetic energy so there are more effective collisions.
- The rate then lowers as enzyme’s active sites are denatured, and no longer complimentary to substrates
[q] How do plants use glucose?
Okay, so what do plants use their glucose for? Can you figure it out?
[a]
[q] How do plants use glucose?
What do plants use glucose/carbohydrates for?
[a]
- Respiration, where glucose is broken down to release energy.
- Cellulose, which is made of long chains of glucose and used to build the cell wall.
- Starch, and sent to the stem or roots for storage.
- Sucrose, which is transported around the plant in the phloem.
- Lipids, to be put in seeds for an energy store when the seed germinates
- Sugars, to go into nectar to attract animal pollinators like bats and insects, and also to make fruit sweet so animals will eat them and disperse the seeds.
[q] What else do plants need?
Do plants need more than glucose?
[a]
- Plants need more than just glucose from photosynthesis.
- They also need minerals and nutrients from the soil!
- Nitrate ions are very important as they are needed to combine with glucose to make amino acids, which are then used to build proteins
- Magnesium ions are also really important. They are needed to make chlorophyll, without which a plant could not do photosynthesis
[q] What would a plant look like without these things?
Can you identify the deficiencies?
[a]
Magnesium deficiency. No magnesium to make chlorophyll so the leaves turn yellow!
Nitrate deficiency. No nitrate ions to make amino acids to make proteins, so much less growth!
[q] What is the structure of a leaf?
What are the parts of a leaf?
[a]
- Can you match the labels to the correct parts of a leaf?
[q] What is the structure of a leaf?
[a]
[q] What does each part of the leaf do?
What is the difference between xylem and phloem?
[a] DIFFERENCE BETWEEN XYLEM AND PHLOEM
[x] Exit text
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