ok rip .... people stating dumb facts
Simple game, just say 1 fact as you go a long.
Russia has a larger surface area than Pluto.
SINCE YOU ARE ASKING FOR NERDISH FACTS HERE YOU ARE.
Photorespiration is a wasteful process that occurs to plants that only do C3-photosynthesis. Photorespiration is due to the fact that RubisCO (C3-photosynthesis enzyme) is capable to fix CO
2, O
2 and ribulose 1,5-biphopshate during the Calvin cycle.
When the plant is in a stable situation and appropriate environment, the stomata are open and therefore, CO
2 can enter the plant and the useless O
2 can exit. At this moment, only CO
2 fixes to RubisCO and C3 photosynthesis can occur since the O
2 exits the plant by the stomata.
When RubisCO fixes 3 ribulose 1,5-biphopshate (5-carbon molecule) and 3 CO
2, it joins the 2 kinds of molecules together in order to produce 3 unstable 6-carbon molecules that split in order to produce 6 G3P (glyceraldehyde-3-phosphate : 3-carbon molecule). 5 G3P are used in order to recycle and to produce the 3 ribulose 1,5-biphopshate in order to use them in the other Calvin cycles and only 1 G3P is used in order to produce carbohydrates. When this process is done twice, 2 G3P are produced and these 2 G3P merge together in order to produce C
6H
12O
6 (glucose).
However, when the plant is in a stressful situation (extreme temperatures), the plan loses H
2O (water) and then, the stomata close since there is not enough water in the vacuole of the cells that make up the stomata and these cells who were turgid and used to make the stomata open, become flaccid and manage to close the stomata. Since the stomata are closed, CO
2 cannot enter the cell anymore and the O
2 produced in the previous photosynthesis accumulates. At this moment RubisCO fixes ribulose 1,5-biphopshate and O
2 and the result of this process is 5 G3P that are recycled and an useless molecule that has to be destroyed by the cell (=> Photorespiration).
Photrespiration is therefore considered as a wasteful process for the plant since plants cannot create carbohydrates anymore when RubisCO fixes O
2 and that's why some plants are less productive in extreme temperatures.
Some plants can do CAM-photosynthesis and C4-photosynthesis in order to resist extreme temperatures. C4-photosynthesis plants have an other enzyme in their mesophyll cells (PEP carboxylase) that only fixes CO
2 while CAM-photosynthesis plants can separate some parts of the photosynthesis (some at night, some at day) in order to avoid photorespiration.
Have fun.
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