Photosynthesis is summarised by the
However this equation is somewhat miss leading, as photosynthesis is a
Photosynthesis is the process by which phototrophs convert carbon
dioxide and water into simple carbohydrates and oxygen in the presence
of chlorophyll, using sunlight.
Several general types of chemical reactions can occur based on what happens when going from reactants to products. The more common types of chemical reactions are as follows:
To understand this, consider the chemical reaction between vinegar (also known as acetic acid to chemists) and baking soda (known as sodium bicarbonate). Before the atoms of acetic acid and sodium bicarbonate can be rearranged to form the products, the bonds between the atoms in those molecules must be broken, and because the atoms are attracted to one another, it takes energy to pull them apart.
Being an evergreen plant it has the advantage of being able to
photosynthesis during the winter months whereas deciduous trees are
The products of photosynthesis, although initially carbohydrates, are
rapidly fed into other biochemical pathways to produce amino acids and
lipids for the requirements of the cells of the plant.
Photosynthesis and Cellular Respiration. Energy Use in Living Organisms Step 1 Convert sunlight energy into chemical food energy Ends in Glucose.
Carbon dioxide from the air combines with ribulose bisphosphate
(RuBP), a 5-carbon compound which fixes the carbon dioxide by
accepting it and making it part of the photosynthetic reactions.
Cellular respiration Aerobic Requires Oxygen Produces 38 ATP from glucose Glucose+ 0 2 -> 6CO 2 +6H 2 0+ 38 ATP 3 steps –Glycolysis, Kreb cycle and ETS Takes place in cytoplasm & mitochondria Result – More energy Anaerobic Does not require Oxygen Produces 2 ATP from glucose Glucose-> Lactic Acid +2 ATP 2 steps – Glycolysis, Lactic Acid formation Takes place in cytoplasm Result- Sore muscles, tired
Thus the reactions of the light-dependent stage of photosynthesis
provide a source of reducing power (NADPH) and the universal
energy-supplying molecule ATP, with oxygen gas given off as a waste
If the leaves have a larger surface area they would absorb a large
amount of light energy and this will increase the rate of
photosynthesis provided that there are no other limiting factors such
as availability of water.
Importance of Oxygen During aerobic respiration, where do the electrons (H + ) end up as they are passed from protein to protein? They end up in the loving arms of oxygen. When oxygen accepts electrons, water is made. If oxygen wasn’t there to accept the electrons, the Electron Transport Chain would get backed up, and no energy would be produced. What type of respiration happens when there is no oxygen? …and where does it happen?
Glucose Glycolysis Cytoplasm Pyruvic acid Electrons carried in NADH Krebs Cycle Electrons carried in NADH and FADH 2 Electron Transport Chain Mitochondrion Cellular Respiration: An Overview Mitochondrion
The excited electron may instead be used to provide the reducing power
needed in the second, light-independent stage of the photosynthetic
Factors that Affect the Rate of Photosynthesis Water – extremely low water amounts reduce or stop photosynthesis. Too much water kills the plant. Temperature – temperatures below 32 O F and above 95 O F slow down photosynthesis. Light intensity – increasing intensity increases photosynthesis up to a certain point, then it levels off and can’t increase any further.