Photosynthesis is an immensely important reaction for life on Earth since plants are the primary producers of food for (nearly) all food chains. They get the energy to make their food from sunlight and use it to split carbon dioxide (CO2) and water (H2O) into their constituent atoms and reassemble them into glucose (C6H12O6) molecules. Some of the oxygen released during this process is needed by the plant for respiration but most of it is released into the atmosphere.
Some of the glucose they use for respiration, some is stored in long chains called starch, and other glucose molecules are arranged into very long chains called cellulose.
The cellulose is used to make plant cell walls and this forms the fibre in your diet.
The catalyst that makes this possible is chlorophyll; a green pigment most usually found in the leaves although often found in other parts of the plant. The chlorophyll is found in tiny structures (organelles) within the cell called chloroplasts.
You should know the word equations for photosynthesis and respiration inside out and back to front and be able to recite them out loud whilst standing on your head. I know I can do this because I just have.
Have a think about the following and post some answers in the comments section below. ADP to ATP in the above equation just means “energy is released” so you could write energy instead.
- From what are cell walls made?
- Why is fibre important in your diet?
- Name an organelle (other than a chloroplast) from inside a cell and say what job it performs.
- Which wavelengths/colours of light is chlorophyll most probably using? How did you come to your answer?
- What is a catalyst?
- [Extension] Where might you find a food chain not dependent on green plants?
Here are my answers…
1. Cellulose.
2. It helps to keep your digestive system healthy.
3. Mitochondria which produce energy.
4. UV because plants absorb UV light.
5. Something that speeds up a reaction.
6. In the Arctic?
Q1 – great
Q2 – indeed. Can you be more specific about what it does?
Q3 – excellent
Q4 – UV is high frequency (short wavelength) light which can be very damaging to living tissues (hence sunburn in humans). Plants don’t use it for photosynthesis.
Q5 – well done. They also sometimes “enable” a reaction i.e. make a reaction happen that would not otherwise happen
Q6 – try not to answer with a “?”. You could support your answer with your reasoning i.e. “because it is too cold for plants to survive”
An arctic food web does have plants, algae and phytoplankton (microscopic aquatic plants), and arctic water is very rich in oxygen because oxygen dissolves better in cold water than in warm water. That is why the cold seas support such a huge population of organisms including the vast baleen whales.
Now I have approved this comment, your others will appear straight away without you having to wait. (As long as you use identical details).
1. Cellulose
2. An important aspect of you diet.
3. Mitochondria, which provide energy to the cell.
4. Visible light, because it reflects green light which is in the visible light range.
5. Something which speeds up or causes a reaction
6. Nowhere
I’m sorry I couldn’t reply earlier I was buying a cat!
Q1 – good
Q2 – yes, but can you be more specific? What job does roughage/dietary fibre do?
Q3 – excellent
Q4 – you have the key point, that it reflects green light so is not using it, so which colours of light is it using?
Q5 – “enables” is better than “causes” but otherwise excellent
Q6 – I reckon there are some places on Earth where there is no light but where organisms live together as a community
Very excited about the cat. Send me a photo!