Description and Function of Cell Structures (Organelles) - by Mr. Hung @ 2014

Description of Cytoplasm

·  the gel-like substance enclosed within the cell membrane

·  basically the substance that fills the cell

·  a semi fluid material surrounding organelles

·  It is a jelly-like material that is eighty percent water and usually clear in color

·  a clear substance that consists of all of the contents except the nucleus

·  a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins

·  the cell substance between the cell membrane and the nucleus

Function of Cytoplasm

·  to provide support to the internal structures of a cell

·  where all the chemical reactions take place

·  to house different organelles inside the cell

Description of Cell membrane

·  a thin semi-permeable membrane that surrounds the cell's cytoplasm, enclosing its contents.

·  Enclosing cytoplasm and organelles

·  Having pores or holes

Function of Cell membrane

·  Allowing substances in and out.

·  regulates the entrance and exit of substances thus maintaining internal balance.

·  It also protects the inner cell from damage

Description of Nucleus

·  Spherical in shape

·  Easily seen if the cells are stained

·  Contains chromosomes or DNA

·  Enclosed by membrane similar to the cell membrane

Function of Nucleus

·  acts like the brain of the cell

·  control centre of the cell

·  controls the cell activities

·  contains hereditary information, or DNA

·  controls cellular growth and reproduction

·  making proteins

Description of Cell Wall

·  rigid and strong layer much thicker than cell membrane

·  consists of fibres called cellulose

·  thicker layer outside the plant cell

·  non-living part of the cell

Function of Cell Wall

·  prevent over expansion when water enters the cell

·  gives support to the cell

·  maintains the shape of the cell

·  extra protection to the cell

·  prevents the cell from injury and being attacked by germs

Description of Large Vacuole

·  Found in plant cells only

·  Like a water bag

·  Contains cell sap

·  Contains mainly water, minerals, and even wastes

Function of Large Vacuole

·  Store water

·  Maintain turgidity of the cell

·  Provide colour necessary to attract insects, butterflies and birds (pollinators)

·  Temporarily storage of wastes

Description of Chloroplast

·  Oval shape

·  Green in colour – because it contains a green pigment called chlorophyll

·  Found only in plant cell, some bacteria and algae

·  Found in green parts of a plant – eg. Young stems and leaves, but not in root (underground)

Function of Chloroplast

·  Chlorophyll is important to trap sunlight for making food during photosynthesis

·  The palisade leaf cells have a lot of chloroplast to carry out photosynthesis

Description of Mitochondrion

·  Sausage shape

·  Many can be found in active cells such as sperm cells, liver cells and cancer cells

Function of Mitochondrion

·  It is called a powerhouse

·  Responsible to release energy - respiration