3boys2girls » 化學物理生物 » 生物@細胞種類係咩黎?咩用 同 特徵 ?

2009-6-14 00:38 annan
生物@細胞種類係咩黎?咩用 同 特徵 ?

個細胞係邊度會有咖? 有咩用 同 特徵 ?

2009-6-14 21:12 magiyafeimo

2009-7-11 21:04 斯_______

2009-8-3 13:58 ~Gloria~
there;s simple two kind of cells: animal cell and plant cell
1, animal cell
inside a animal cell, there;s
- cell membrane
- cytoplam
- nucleus
- rough endoplasmic reticulum
- smooth endoplasmic reticulum
- mitochondrion (pural:mitochondria)
- vacuole
i,cell membrane:
  -thin, flexible (surround the cell)
  -differentially permeable (only allow SOME substances to pass through)
      ~controls the movement of substance into and out if the cell
  -jelly-like substance (consisting of water, proteins and other chemical subsrances)
  -holds all the organelles (e.g. nucleus, endoplasmic reticulum, mitochondria, vacuole)
  -provides place for chemical reactions to take place in the cellx
  -round-shaped, bounded by the nuclear membrane
  -contains DNA, the genetic material of life
  -contains thread-like chromosomes: ~ carry genetic information
                                                   ~ controls all activities of the cells
iv,endoplasmic reticulum (ER)
  -a network of interconnected membrance-bound sacs
  -forms a link between the cytoplasm and the nuclear membrane
  -two types of ER: a,rough ER: with ribosomes attached to the surface
                                            ribosomes on it are the sites of protein synthesis
                           b,smooth ER:without ribosomes attached to the surface
                                            involved in the synthesis and transport of lipids
  -rod-shaped, bounded by a double membrane
   (the iner member is folded into finger-loke projections)
  -main site (the energy-releasing stage of respiration takes place)
  -a space containing water and dissolved substances (e.g. food,enzymes)
  -bounded by a differentially permeable membrane
  -contain/ holds useful substamces (sugar) or sometimes wastes
  -most animals cells usually have only a few small or even no vacuole

2,plant cell
inside a plant cell, there;s
- cell membrance
- cell wall
- chloroplast
- cytoplasm
- vacuole
- nucleus
- rough endoplasmic reticulum
- smooth endoplasmic reticulum
- mitochondrioin
i,cell wall
  -thick, rigid layer covering the cell membrane
  -mainly made up of cellulose
  -fully permeable
  -protects, supports and gives shape to plant cells
ii, large central vacuole
  -contains cell sap (a solution of dissolced substances e.g. food,pigment,wastes)
  -usually large, located at the centre of the cell
  -when it;s full of water, the cell become turgid:provide support to the plant
  -bounded by a double membrane
  -contains a green pigment----chlorophyll:absorbs light energy for photosynthesis

i types these by myself
not from internet
hope this can help you ;)

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