CELLS

Cells

• cells are the smallest unit of living tissue
• in ANIMAL cells:
• nucleus-controls all activities of cell, contains instructions for making new cells/organisms
• cell membrane-controls passage of substances in and out of cell
• cytoplasm-liquid gell in which most of the chemical reactions needed for life take place
• mitochodria-structures in cytoplasm where oxygen is used and most of the energy is released during respiration
• ribosomes-where protein synthesis takes place, all proteins needed in cell made here
• in PLANT cells:
• same features as animal cells
• cellulose cell wall- in all plant cells; strengthens cell and gives it support
• permanent vacuole-in most plant cells; keeps plant rigid to support plant
• chloroplasts-only in cells that live above sea level; absorb light to make food by photosynthesis

Specialised cells

• smallest living organisms are single cells
• carry out all functions of life (eg. feeding, respiration, excretion, reproduction)
• most organisms are bigger and made up of lots of cells
• some become specialised in order to carry out particular jobs
• when becomes specialised its structure adapted to suit particular job it does
• as result they often look very different to 'typical' animal/plant cells

Root Hair Cell

• in plants
• increase surface area for water to move into the cell
• has large permanent vacuole- affects movement of…