Download Leaf structure and minerals

LEAF STRUCTURE
MINERAL REQUIREMENTS
Cross section of a leaf
Xylem/ Phloem
Stomata
2 guard cells control the opening and closing of stomat
Function of leaf parts (Review)
Structure
Function
Epidermis
Top thin layer (protective). Prevents water loss and over heating
of leaf
Cuticle
Waxy layer of the epidermis- Prevents water loss and over
heating of leaf
Spongy
Mesophyll /
Palisade cells
Photosynthesis – there are more chloroplast in the palisade cells
than the mesophyll cells are- this is where the majority of
photosynthesis happens. Palisades are long – to maximize
surface area. Spongy cells are round and few – allows for air to
travel to the palisade cells (gas exchange)
stomata
Allows air to come in and out of leaf ( gas exchange)
Guard cells
Control the opening and closing of stomata
Vascular bundle
Has the xylem and phloem running through the leaf
xylem
Transports water into the leaf / structural support
phloem
Takes substance away (sugar) that the leaf has made to other
pars of the cell / structurally support
Mineral Requirements
 Plants can use the carbohydrates they make to make
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protein.
Proteins – C/H/O/ & N (Nitorgen)
Plants get their nitrogen from inorganic compounds
like nitrate ions and ammonia ions.
Even though 80% of air is nitrogen oxide – it is
mostly useless to plants as it is unreactive
Nitrates (NO3- / NH4+) taken up by roots
If not enough nitrates – can’t make protein / can’t
make new cells
The plant will have stunt (short) growth / weak
 Nitrates are needed to make enzymes for the plants
 Smaller / less green / less healthy
 Farmers can supplement this by adding nitrates to
the soil in form of fertilizer
Magnesium ions:
- Needed to make green pigment in chlorophyll
- Plant leaves become yellow if magnesium not there
quickly
- Efficiency of photosynthesis goes down