Biology - Cells

Nucleus -> Controls everything that happens in the cell & contains information to make new cells

Cytoplasm -> Jelly lilke substance in which chemical reactions of the cell take place. These reactions are controlled by enzymes

Cell Membrane -> Gives the cell its shape and contols which substances enter and leave the cell

Ribosomes -> Where the proteins are made

Plant cells:

Cell wall -> Found outside the cell membrane. Made of cellulose amd strengthens the cell.

Chloroplasts -> Found in cytoplasm of many plant cells. They absorb light energy to make photosynthesis

Vacuole -> Large sac in center of cytoplasm. Contains a watery fluid called cell sap.

Plant cells:                                                                                   Animal Cells:

Tough cell walls for support                                               No cell walls

Many have chloroplasts                                                     No chloroplasts

Large permeable vacuole containing                                 Some have small
cell sap                                                                            vacuoles, but no cell sap

Many have box like shape                                                   Shape varies

Tissues:

Are groups of identical cells that all do the same job.
For example: Heart muscle cells form heart muscle tissue throughout your life

Organs:

Made up of groups of tissues.
For example your heart is made up of muscle tissue, blood tissue and nerve tissue.
These tissues all do different jobs, but work together to pump blood around your body. They work together to do a particular job.

Number of organs working together makes up a system.

Mitochondria
-Small sausage shaped structures that can only be seen under an electron microscope
- Found in cytoplasm
- Release Energy from respiration
--------------------------------------------------------------------------------------------------------

Specialised cells- Cells that have developed to a specific job.

E.g. Sperm cells have tails to swim
        Red blood cells contain substance that carries oxygen

DIFFUSION:

Diffusion is the movement of paricles from a region of high concentration to a region of lower concentration until they are evenly spread out.

OSMOSIS:

Osmosis is the diffusion of water molecules from dilute solution to a more concentrated solution through a partially permeable membrane