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PLANT STRUCTURE AND FUNCTION - Coggle Diagram
PLANT STRUCTURE AND FUNCTION
Stem Cells
Xylem
Xylem is located towards the center of the vascular bundle,
Carries water and dissolved mineral ions from the roots to the photosynthetic parts of the plants
Consists of four types of cells: tracheids(support), vessel elements(allow water to move), fibers, and parenchyma cells(store and transport water and nutrients).
Phloem
phloem is located towards the outside.of the vascular bundle
Transport dissolved product of photosynthesis from the leaves to part of the plants where it's needed.
Consists of four types of cells: sieve-tube elements(allow transport), companion cells(regulate flow of materials), fibers, and parenchyma cells(store and transport water and nutrients).
sclerenchyma
Schlerenchyma is found in the cortex and the pith of the stem
Schlerenchyma provides mechanical support to the plant
Composed of dead cells with thick cell walls, with an oblique pits and branched sometimes. Has a very thick lignified cell walls and empty lumen with no living contents
The importance of water and inorganic ions
Calcium
Make calcium pectate to maintain the cell wall rigid and turgid
Maintain permeability of membranes
Without calcium, the growing points die back and the leaves become crinkly.
Magnesium
Make chlorophyll to trap light for photosynthesis
Activation of plant enzymes
Synthesis of nucleic acids
Without Magnesium, growths slow down, and photosynthesis cannot occur.
Nitrates
Make DNA , hormones and other compounds
Without nitrate, leaves turn yellow and the plant dies.
Make amino acids and proteins which the cell could not function without
Water
Forces the cytoplasm againts the cell wall, so the plant can stand still
Transport Minerals and nutrients
Photosynthesis Purposes
How Plant and Animal Cells compare
Plants Cells
Have specific structure, such as chloroplast, cell wall, vacuole, amyloplast, and plasmodesmata.
Have 1 big nucleus
Tonoplast present around vacuole
Synthesize Nutrients
Nucleus on the side
Centrioles only present in motile cells of lower plants
Starch grains as the source of storage material
Animal Cells
Tonoplast absent
Does not have chloroplast, cell wall , amyloplast, and plasmodesmata.
Centrioles Present
Glycogen granules as the source of storage material
Have many nucleus but temporary
Cannot synthesize nutrients
Nucleus on the centre
Structure and ultrastructure of plant cells and their functions
Cell wall
Protection
Provides semi permeable surface
Support
Chloroplast
Photosynthesis Purpose
Trap light by chlorophyll
Amyloplast
Store starch
Provide energy by converting starch into glucose
Vacuole
Store poison
Store waste products
Store enzymes
Cell sap
Store materials
Mechanical Support
Tonoplast
Keep contents in vacuole
Control in and out of substance
Plasmodesmata
Exchange of cytoplasmic material between cells
Communicator
Pits
Transport water and minerals into the surrounding cells
MIddle lamella
link of cell wall between plant cells
Cellulose Microfibrils in xylem and schlerenchyma
Xylem
Arrangement: Cellulose microfibrils in the walls of the xylem vessels are arranged vertically in the stem to increase the strength of the tube and allow it to resist the weight of the plant pressing it down.
The thickening occurs in the form of lignin, a complex organic polymer that is highly resistant to degradation.Making the cell impermeable to water and other substance and the tissue becomes stronger
Schlerenchyma
Arrangement: Cellulose microfibrils in the walls are arranged in parralel which provides strength and support. It contributes to their ability to resist stretching and bending forces.
The secondary thickening of the cell walls in sclerenchyma fibers occurs in a similar way to xylem vessels, with the deposition of lignin.Making the fibres strong and flexible.
The structure and function of the polysaccharides starch and cellulose
Cellulose: long chains of glucose joined by glycosidic bonds.
Structure: Their structure consists of monomer units of beta-glucose joined by 1,4 glycosidic bonds and it remains as long, straight chains.
Function: act as a roughage (aid the passage of food to be digested / excreted) or fibre in the human diet, which is an essential part in a healthy diet as Cellulose cannot be digested.
Starch: long chains of glucose joined by glycosidic bonds
Structure: Their structure consists of monomer units of alpha-glucose joined by 1,4 and 1,6 glycosidic bonds and it forms compact globular molecules
Function: acts as an important energy source in the diet of many animals. The structure of mix 1,4 and 1,6 is intended to store the sugar in the most compact position.