All about photosynthesis

6. 6CO 2 + 12H 2 O + light -> C 6 H 12 O 6 + 6O 2 + 6H 2 O

21. Carbon dioxide is converted to sugar using ATP and NADPH. Carbon dioxide is combined with a 5-carbon sugar creating a 6-carbon sugar. The 6-carbon sugar is eventually broken-down into two molecules, glucose and fructose. These two molecules make sucrose or sugar.

26. Many factors affect the rate at which photosynthesis occurs. Because water is one of the raw materials of photosynthesis, a shortage of water can slow or even stop photosynthesis. Plants that live in dry conditions, such as desert plants and conifers, have a waxy coating on their leaves that reduces water loss.

27. Depends on enzymes that function best between 0°C and 35°C. Temperatures above or below this range may damage the enzymes, slowing down the rate of photosynthesis. very low temperatures - photosynthesis may stop entirely. very high temperatures - enzymes are denatured. Optimum temperature: 25 o C to 35 o C Since both the stages of photosynthesis require enzyme activity, The temperature has an effect on the rate of photosynthesis.

28. Graph Showing Effect of Temperature on Rate of Photosynthesis

29. Increasing light intensity increases the rate of photosynthesis. After the light intensity reaches a certain level - plant reaches its maximum rate of photosynthesis. The level at which light intensity no longer affects photosynthesis varies from plant type to plant type. Light intensity increases:. the rate of the light-dependent reaction, and photosynthesis also increases As light intensity is increased, the rate of photosynthesis is eventually limited by some other factor. Chlorophyll a is used in both photosystems. PSI absorbs energy most efficiently at 700 nm and PSII at 680 nm. Light with a high proportion of energy concentrated in these wavelengths will produce a high rate of photosynthesis.

31. 0.1% of carbon dioxide in the atmosphere increases the rate of photosynthesis significantly. This is achieved in the greenhouses which are enclosed chambers where plants are grown under controlled conditions. The concentration is increased by installing gas burners which liberate carbon dioxide as the gas burns. Crops like tomatoes, lettuce are successfully grown in the greenhouses. These greenhouse crops are found to be bigger and better-yielding than their counterparts growing in natural conditions. An increase in the carbon dioxide concentration increases the rate at which carbon is incorporated into carbohydrate in the light-independent reaction Rate of photosynthesis generally increases until limited by another factor.

32. Light Intensity