Knowledge Flashcards
What is Photosynthesis?
The chemical change that occurs within the leaves of green plants, which converts sunlight into chemical energy in the form of glucose.
Where does Photosynthesis take place?
In the leaves of green plants, specifically inside the chloroplasts of the plant cell.
Is Photosynthesis endothermic or exothermic?
Endothermic - absorbs sunlight.
Word equation for photosynthesis?
Carbon dioxide + water ——> oxygen + glucose
Light energy above arrow
Chlorophyll below arrow.
Balanced symbol equation?
6CO2 + 6H2O ——> C6H12O6 + 6O2
Uses of glucose produced in photosynthesis?
Respiration
Storage - starch
Converted into cellulose/chlorophyll
Factors that affect photosynthesis?
Light intensity Carbon dioxide Temperature Water Amount of chlorophyll
How does light intensity affect photosynthesis.
When the intensity of light is increased, so does the rate of photosynthesis, up until a point - other limiting factor holding back rate.
How does CO2 affect photosynthesis?
If the amount of CO2 increases so does the rate of photosynthesis, up until a point - other limiting factor.
How does temperature affect rate of photosynthesis?
As temperature increases so does rate of photosynthesis, up until around 30 degrees, after this enzymes start to denature.
On a graph, measuring one factor, why does the curve flatten out.
Due to a limiting factor. E.g - a plant can only absorb so much light, after this either amount of CO2 or temperature is holding back rate.
2 reasons for plants adaptions.
To maximise light absorption
Maximise rate of gas exchange
Layers of the leaf from top to bottom?
Waxy cuticle Upper epidermis Palisade mesophyll Spongy mesophyll ( mixed in - vascular bundle - contains xylem, phloem) Lower epidermis Guard cells and stomata
How are palisade mesophyll adapted for efficient light absorption.
Position just under top of leaf - closer to sunlight. Full of chloroplasts.
How are spongy mesophyll adapted to has exchanged?
Spaced out leaving air gaps. Circular to increase surface area and loosely packed.
