production of food as carbohydrates, proteins, fats and vitamins -
It is the source of industrial row materials as wood, fibers ,fats. etc -
It is the source of fuels such as coal, petroleum and natural gas -
It is the source of oxygen required for respiration process -
[b][b][color=#bb00bb]Raw materials required for photosynthesis *[/color][/b][/b]
[b]Water[/b] : is the source of hydrogen needed to reduce CO2 -
[b]CO2[/b] is the source of carbon which reduced to form carbohydrate -
[b]Phosphorus[/b]: is required in producing energy compounds [b][u]ATP[/u][/b] -
[b]Magnesium[/b]: is required in the formation of chlorophyll molecules -
[b]Iron[/b]: is important for building up of some photosynthesis enzymes -
[b]Mineral salts[/b]: as nitrates, phosphates & sulphates to convert carbohydrates into proteins -
[b][color=#8800bb]Products of photosynthesis[/color][/b]
Monosaccharides are the main products of photosynthesis
Oxygen the second product of photosynthesis
[b][color=#bb0088]
The structure of the chlorophyll molecule, is C55 H72 O5 N4Mg -
The Mg atom at centre -[/color][/b]
[b][color=#8800ff]The rate of photosynthesis can be determined by[/color][/b]
Estimating the amount of carbohydrates. [b][color=#8800bb]1 gm/hour /m2[/color][/b] -
counting the number of O2 bubbles which evolve in a unit time -
[b][color=#8800ff][CENTER]the structure of the chloroplast[/CENTER][/color][/b]
( [b][color=#440088]Double thin membrane[/color] + [color=#ff4400]Stroma[/color] + [color=#8800ff]Grana[/color] ) [/b]
The cells are barrel shaped to converge the light into the inner tissue -
The cells are transparent to allow the passage of the sun rays -
It is covered with cutin to protect the leaf against pests &decrease water toss -
The cells are adjacent and compact to protect the inner tissues -
[b]The mesophyll lies between the upper & the lower epidermal layers[/b]
[b][color=#4400bb]Spongy tissue[/color][/b] *
It is irregular parenchyma cells -
It has wide intercellular spaces -
It has a few No. of chloroplasts -
Its functions are store food, gas exchange and photosynthesis -
[b][color=#4400ff]palisade tissue[/color][/b]
cylindrical, parenchyma cells -
has narrow intercellular spaces -
has many chloroplasts -
its function is the photosynthesis -
The vascular tissue is formed of many vascular bundles distributed in the veins & venules *
[b][color=#880088]The vascular system in the leaf[/color][/b] **
They are arranged inside the bundle towards to the upper epidermis, The protoxylem are -
directed upwards
Xylem vessels and separated by xylem parenchyma -
[b]The function of the xylem[/b]: support & supply the leaf with water&salts -
Phloem lies toward to the lower epidermis, It consists of sieve tubes, companion cells and phloem parenchyma
[b]The function of the phloem[/b] it transport the soluble organic food from the mesophyll to the other plant parts -
[b][color=#000088][CENTER]The Mechanism Of Photosynthesise[/CENTER][/color][/b]
[b][color=#440044]The source of the released O2[/color][/b]
Van Neil studied green purple bacteria which contain simple chlorophyll -
Green purple bacteria use H2S as a source of Hydrogen instead of H2O
[b][color=#ff00ff]An experiment to prove that H2O is the source of O2 in photosynthesis[/color][/b]
The Chlorella algae was divided into two groups, each group was left to carry out photosynthesis as following
A) The first group of the algae was left to absorb H2O formed of radioactive Oxygen O18 while the CO2 was formed of non-radioactive Oxygen O16 the results was as the following
[IMG]http://www.theegypedia.org/components/com_kunena/template/default/images/emoticons/cool.png[/IMG] The experiment was repeated after reversing the consitions H2O formed of normal O16 while CO2 has O "18" the results was as following
[b][color=#8800bb]light and dark reactions[/color][/b]
Blackman concluded that photosynthesis takes place in two main steps, light & dark reactions -
[b][color=#880088]The light reactions[/color][/b]
([b]the light is the limited factor [/b])
[b]When[/b] the chloroplast are exposed to light some electrons gain energy and move from lower energy level higherone ,so the light energy change into potential chemical energy The chlorophyll
[b]Part of[/b] the active chlorophyll energy is used in splitting H2O into H + NADP = NADPH2. & O2 releases
[b]The other[/b] part of the energy change ADP into ATP