Cells

CellsSarah Jones

The Discovery of CellsIn the seventeenth century, Robert Hooke looked

at thin slices of cork under a microscope that he

had made from lenses. He observed small box-like

shapes inside the cork. He called the little boxes

that he saw cells.

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Under the five kingdom system cells can be divided into two basic types.

Prokaryotic cells - simple cells without distinct membrane bound organelles or nucleus.

Eukaryotic cells - more complex with membrane bound organelles and nucleus.

Animal Cell

• Exist as part of a multicellular organism.• Specialisation of cells into many types (cell

differentiation).• Possess nucleus and membrane bound

organelles. • Many different types.

Plant Cell

• Exist as part of a multicellular organism.• Specialisation of cells into many types (cell

differentiation).• Possess nucleus and membrane bound

organelles.

Plant vs Animal

Plant and animal cells have many similarities

because they are both eukaryotic.

They also have some differences:

Parts of a Generalised Animal Cell

• Contains the chromosomes (genetic

information) for the cell.• Controls the activities of the cell.

Nucleus

• Double membrane - outer membrane and

inner membrane.• Inner membrane is folded forming cristae.• The interior contains an organic matrix

containing chemical compounds.• Site of aerobic respiration.

Mitochondria

Rough Endoplasmic Reticulum• A membrane system of flattened parallel

cavities which are interconnected and covered

with ribosomes.• An intracellular transport system.

Golgi Apparatus• Consists of a stack of flattened cavities which

package substances produced by the cell into

vesicles.• These vesicles can fuse with the cell

membrane (exocytosis) or become lysosomes

(digestive vesicles).

Plant Cell Walls• The main component of plant cell walls is

cellulose.• Cellulose molecules are arranged in bundles

called microfibrils.• The function of the plant cell wall is to provide

strength and support the plant.

Prokaryotic organisms are commonly called

bacteria.

They are cells with a simple structure.

They have no membrane around the nucleus

and lack any membrane bound organelles.

Blue-green bacteria make their own food by photosynthesis.

Cell Division