Eukaryotic cell- Plant cells

• lable the plant cell

  A) Vesicles

  B) Mitochondria

  C) RER

  D) Nucleolus

  E) Vacuole

  F) Cell wall

  G) Cytoplasm

  H) cell membrane

  I) plasmodesmata

  J) SER

  K) Nucleus

  L) Golgi body

  M) chloroplast

  
• Plant cell wall consist mainly of cellulose fibres.​

  They give plant cells strength and rigidity. This means that plant cells cannot burst when they take in water like animal cells do.​

  When plant cells absorb water the cells become turgid and exert hydrostatic pressure on each other which supports plant stems and leaves. This is why plants go limp if they are short of water.
• The cell wall does not seal off a cell completely from its neighbours. ​

  There are pores within the walls called plasmodesmata. ​

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  These connect two cells together by their cytoplasm, enabling the exchange and transport of substances.​
• • Pits are relatively thinner portions of the cell wall that adjacent cells can communicate or exchange fluid through.​
  • This is particularly useful in xylem vessels, where it allows for the lateral flow of water and mineral ions between adjacent vessels​
• • Chloroplast are about 3-10µm (average 5 µm ) in diameter.​
  • ​They are surrounded by 2 membranes which forms the chloroplast envelope.​
  •  The chloroplast contain chlorophyll and other photosynthetic pigments.​

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  • Within the chloroplast are the thylkoid membranes, which  are the site of light in photosynthesis.
• The thylakoid are often layered into stacks called grana (sing=granum) at intervals.​

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  The stroma is the fluid which fills the interior of the chloroplast  and surrounds the thylkoids.​

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  Stroma contains many enzymes which catalyse the light independent reactions of photosynthesis.​

  Lipid droplets are also present in the chloroplast.​

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  Loops of double stranded DNA are also present in the chloroplast.​
• • The vacuole is a sac in plant cells surrounded by the tonoplast (selectively permeable membrane)​
  • They are large, permanent structures in a plant cell​
  • Contains cell sap, which is a mixture of different substances such as water, minerals, waste and enzymes. The vacuole also acts as a store of molecules. ​
  • The concentration of the cell sap enables water to enter the vacuole by osmosis. Hence vacuole help maintain the turgor pressure in the cell.​