The main variables which affect photosynthesis are light, water, CO2 concentration and temperature.
On a deeper level, other factors like amount of chlorophyll, availability of nutrients (eg Mg is needed for chlorophyll synthesis) will also affect the rate of photosynthesis, though these are rarely covered in discussion of this topic.
The thing is that photosynthesis will be held back by whichever factor is in shortest supply.
As I sit in my study in England, the sun is shining brightly, but the temperature outside is only 5ºC. I suspect the rate of photosynthesis is limited by temperature today.
Yesterday was a dull day, but in the middle of the day it was not cold and I suspect there wasn't enough light for photosynthesis. If I had turned the security lights on my house on, the plants in my garden might (possibly) have photosynthesised faster.
In summer, some farmers growing crops in glasshouses actually increase the amount of carbon dioxide in the air as all their plants have plenty of water and light and the temperature is near the best possible for photosynthesis.
A good way to investigate this might be with the help of algae and you can use the 'Immobilised Algae' practical for this.
Although water is needed as a raw material for photosynthesis, don't bother trying to investigate water as a variable - plants normally wilt and wither long before water restricts photosynthesis at the biochemical level. They need water to support the plant to face the sun as well as a raw material of photosynthesis.
The simplest equation for photosynthesis:-
Carbon dioxide + water -----(in light, with chlorophyll and enzymes)----> sugar + oxygen
Temperature speeds up all chemical reactions - photosynthesis is no exception.
Enzymes work better in warm conditions (up to about 50ºC when enzymes start to be destroyed by heat).
The idea to get across is that different conditions will be most important on different occasions. This morning, my garden could do with more warmth - yesterday, it could do with more light / sun!
Answer:
In general, it is possible to affirm that in areas where there is malnutrition there are high deficits in all the essential vitamins for humans. A characteristic poor diet in these countries occasionally lacks vitamins and with this malnutrition. However, the reports mainly focus on deficits of vitamin A and D because there are more investigations. Vitamins are essential substances for the body and its function and cannot be synthesized by the same body but must be ingested from food. Vitamin deficiency is considered serious because it causes blindness and even death.
Answer:
If the oil spilled in the gulf would have been processed oil, it would be worse than a normal oil spill as these oils have a higher shelf life.
Explanation:
Oil spills happen when a large quantity of oil gets mixed with large water bodies like <em>sea and oceans</em>. The oil being denser than water floats on the surface and does not mix with the water. It forms a coating on top of the water.
The difference between processed oil and normal oil is that they are heated at very <u>high temperatures</u> and this results in oxidation which creates <em>free radicals</em>, which are not good for the body and its cells. Also they have a very long shelf life due to which they will remain on water for a long time.
When oil spills happen, the <em>wind</em> cause the spill to spread over the water surface, thereby engulfing a large amount of area. The major disadvantages of the spill are:-
- The oil gets stuck in the feathers of the birds who come by to dip themselves,
- Animals like whale, dolphins have blow holes for releasing water. the oil covers these holes and makes it difficult for them to breathe.
- The fur of animals like <u>seal and otter </u>gets mixed with the oil and can prove harmful to them as it gets them exposed to cold.
- The overall BOD of the water body decreases, and organisms which use sun rays coming inside the ocean suffer as these get blocked.
- Since processed oil has longer shelf life, a large quantity of animals will suffer and die.
Observation is broken up into three parts. The first is the date. Then you have the activity and last you have a brief description of what is being observed.
