Photosynthesis Flashcards
Define photosynthesis
A process whereby carbon dioxide and water are combined, in the presence of chlorophyll and light energy, to form energy rich carbohydrates. During this process oxygen is released
Photosynthesis can be done by heterotrophs or autotrophs. Why?
Autotrophic organisms since they manufacture their own food and are therefore producers in any ecosystem
Where does photosynthesis occur?
Within the chloroplast of plant cells
Requirements for photosynthesis?
- carbon dioxide: from atmosphere
- water: absorbed by root and delivered via xylem
- chlorophyll (present in chloroplast)
- energy (sunlight)
- enzymes
Products of photosynthesis?
- glucose: high-energy; soluble; converted to insoluble starch and stored
- oxygen: released into atmosphere via stomatal pores
Reaction for photosynthesis
6CO² + 6H²O~> C⁶H¹²O⁶ + 6O²
Carbon dioxide + water ~light, chlorophyll, enzymes~> glucose + oxygen
Photosynthesis is divided into 2 phases the…?
Light dependent phase(light phase)
-Light energy is essential
Light independent phase(dark phase)
-Light is not required
Where do Light dependent reactions occur?
On photosynthetic membranes
Structure of a chloroplast
- starch grain(stores starch)
- intergranum
- granum(stack of thylakiods)
- stomata
- thylakiod
- double membrane
Function of the double membrane?
Permeable to oxygen, CO², water and glucose
Function of the granum(Stack of thylakiods) and the intergranum?
Stacked thylakiods increase area for light absorption
The intergranum connects one granum to another
Function of the thylakiod?
- photosynthetic membranes
- contains chlorophyll for photosynthesis
List the functions of the stroma
- a semi-liquid that bathes the interior of chloroplasts
- contains enzymes for light independent phase for photosynthesis
- has ribosomes which make enzymes for photosynthesis
Where does the light phase(light-dependent) take place?
In the grana (of the chloroplast)
Where does the dark phase(light-independent) take place?
In the stroma (of the chloroplast)