Most animal and plant cells contain a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant cells containall the structures seen in animal cells as well as a cell wall and, in many cases, chloroplasts and a permanent vacuole filled with sap. Enzymes control the chemical reactions inside the cells.

Nucleus: Controls cell activities, contains instructions for making new cells and organisms.

Cytoplasm: Liquid gel where most chemical reactions take place.

Cell Membrane: Controls passages of substances in and out of the cell.

Mitochondria: Structures in the cytoplasm where most of the energy is released in respiration.

Ribosomes: protein synthesis happens. All proteins for the cell are made here.

Cell Wall: Made of cellulose which strengthens the cell and supports it.

Chloroplasts: Green bits, contain chlorophyll, they absorb light energy to make food for photosynthesis.

Permanent Vacuole: Space in cytoplasm filled with sap which is important to keep the cell rigid.

Enzymes are important because:
    they control reactions of respiration in the mitochondria.
    they control reactions of photosynthesis in the chloroplasts.
    they control reactions of protein synthesis found on the ribosomes.

Specialised cells are often grouped together to form a tissue. Connective tissue joins bits of your body together. Nervous tissue carries information around your body to make it do things.