Cells and living processes

Characteristics of living things-

Movement, respiration, sensitivity, nutrition, excretion, reproduction and growth. Many organisms consist of one living cell. 

Division of labour-

Most organisms are found in both plant and animal cells. Same functions in each type of cell. Each type of organism has specific role, this is called 'division of labour'. Different organelles work together to contribute to the survival of the cell. 

Movement and stability of the cell- 

Cytoskeleton- 

Cells contain a network of fibres made of protein. Keep cells shape stable by providin internal framework- cytoskeleton. Actin filaments move against eachother to cause movement seen in WBC. Also move some organelles around inside cell. 

Microtubules made of protein tubulin. Can be used to move microorganism through liquid or waft it past cell. Other proteins on microtubules move organelles and other contents along

 fibres- how chroimosome are moves during mitosis. How vesticles move from endoplasmic reticulum to golgi apparatus, these proteins are known as microtubule motors, uses ATP. 

Flagella and cilia- 

In eukaryotes flagella and cilia are structurally the same. Hair like extensions that stick out of surface of cell. Each one made from cylinder containing 9 microtubules arranged in a circle and 2 microtubules in centre bundle. Flagella (also known as undulipodia) are longer than cilia.  It forms tail of sperm cell that can move whole cell. In ciliatyed epithelial tissue, sweeping movemet of cilia move substances such as mucus across surface of cell. Flagella dn cilia can move because the microtubules can use energy from ATP. Cilia often occur in large numbers on cell but only one or two flagella. 

Vesticles and vacuoles- 

Vesticles are membrane bound sacs found in cells, used to carry different substances around cells. In plant cells the large cell vacuole maintainscell stability. Filled with water and solutes that push cytoplasms against walls, making turgid. Cell being turgid it helps support the plant.