Photosynthesis Flashcards
photosynthesis
process by which plants manufacture their own food
how are plants adapted to manufacture their own food
they contain a pigment called chlorophyll, it is found in the chloroplasts of the plant cells
chemosynthesis
process by which bacteria make their own food , the obtain the energy required through certain chemical reactions
what is a producer
an organism that manufacture its own food and it does not have to produce its food through the process photosynthesis
chemical equation for photosynthesis
CO2 + H2O +sunlight—————>O2 +C6H12O6
how is the chloroplast adapted for photosynthesis?
1) The double membrane allows CO2 and water to enter the chloroplast
2) the starch granules store starch
3) the ribosomes are a site of protein synthesis this is where enzymes are manufactured and these enzymes are used in the dark phase
4) the thylakoids contain chlorophyll and chlorophyll traps sunlight
5) the stroma increases the surface area to trap sunlight
light phase
a phase in photosynthesis that is dependent on light, that occurs in the grana because the grana contains chlorophyll and the chlorophyll absorbs radiant energy from the sun
how is radiant energy used in the light phase
- used to form AT[P
- used to split the water molecules into hydrogen and oxygen atoms
what is the purpose of hydrogen atoms in the light phase
the hydrogen atoms are high in energy ,they combine with co-enzymes that carry them to the dark phase. The O2 is released into the atmosphere as a by-product ,the O2 then leaves the leaves through the stomata
explain the dark phase
- independent of light, occurs in the stroma
- the CO2 provides the carbon & oxygen
- the carbon and oxygen combine with the high energy hydrogen atoms of the light phase to form the high energy carbohydrates such as glucose .
- this reaction requires a lot of energy , this energy comes from the high energy atoms and ATP molecules
what is produced as a by-product in the light phase and dark phase?
light phase - Oxygen
dark phase -glucose [C6H12O6]
Importance of photosynthesis
- provides a primary source of food for all organisms
- provides oxygen ,which is needed for respiration for most living organisms
- fossils fuels such as coals and oils are derived from plants,( the energy stored in these fossils fuels were originally trapped from the sun during photosynthesis
the role of ATP
provides energy for cells
it is an energy carrier used by living cells
how does temperature affect the rate of photosynthesis
an increase in temperature can speed up the process of photosynthesis but when the temperature reaches an optimum(30 degrees C) the rate of photosynthesis slows downs because the enzymes controlling photosynthesis have become denatured and can no longer function. Temperature is a limiting factor
