Leaves And Photosynthesis Flashcards
What features make plant cells different from animal cells
They contain cholorplasts, a central vacuole and a cell wall
Where in the plant does photosynthesis occur
In the leaves (chloroplasts)
How have leaves adapted to be efficient at photosynthesis
Contains chlorophyll which absorbs light in the chloroplasts
Broad and flat to have huge surface ares to absorb sunlight
Thin structure so gases and light have short distance to travel
Stomata on underside allows gas to diffuse in and out
Vascular bundle network transports water to cells and removes products of photosynthesis ie. Glucose
What is the gaseous exchange
Carbon dioxide diffuses in through the stomata
Oxygen produced by photosynthesis diffuses out
Chlorophyll is a mixture of several pigments that absorb slightly different wavelengths of light
What colours in the spectrum are mainly absorbed
Maximum rates are reds and purples in the spectrum
Greener colours are clearly reflected explaining why plants are generally green🌱
What are the four distinct sections found in the structure of a leaf
Upper epidermis
Palisade layer
Spongy mesophyll
Lower epidermis
What is the function of the waxy cuticle
Restricts water loss from leaf
What is the function of the upper epidermis
How is is adapted for the function
Transparent to allow light through to the layer below (palisade layer contains the chloroplasts)
What is the function of the cells in the palisade layer
How is it adapted to do this
Cells in palisade layer are positioned near the top of the leaf to absorb maximum amount of light
Large concentration of chloroplasts to absorb light energy needed for photosynthesis
What is the function of the spongy mesophyll
How is it adapted to do this
Contains lots of air space connected to the stomata to ensure optimum exchange of gas 💨
What is the function of the stomata
Lower epidermis
The lower epidermis contains most of the stomata
The stomata allow diffusion of carbon dioxide in and the oxygen produced out of the leaf🍃
GASEOUS EXCHANGE
It also allows water to pass out of the leaf
What is the function of the guard cells
How do they do their function
They control the size of the stomata to restrict water loss
Guard cells lose water by osmosis and become flaccid causing them to open the stomata
This allows carbon dioxide in and oxygen out
What is the function of vascular bundles
They contain xylem and phloem to transport water and sugars through the leaf
What can improve the rate of gaseous exchange in the leaves
Leaves have large internal surface area-to-volume ratio improving the rate of gaseous exchange between photosynthesising cells and the air space
