Cell Structure

Cell Structure

You must be able to: Describe the structure of a typical animal cell Describe how a plant cell differs from an animal cell Recall the main differences between prokaryotic and eukaryotic cells Describe the structure of a typical bacterial cell

Generalized Structure Of Plant Cell (binary/octet-stream)

A Typical Animal Cell

All cells have structures inside of them - these are called sub - cellular structures In an animal cell, the sub - cellular structures include: a nucleus, which controls the activities of the cell and contains the genetic material cytoplasm, in which most of the chemical reactions take place a cell membrane, which controls the passage of substances into and out of the cell mitochondria, where aerobic respiration takes place ribosomes, where proteins are synthesised (made)

Caption: : Animal Cell

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Plant cells

Caption: : Plant Cell

Plant cells and algal cells contain all the sub - cellular structures found in animal cells They also have:   a cell wall made of cellulose, which strengthens the cell a permanent vacuole filled with cell sap, which supports the plant ​​​​​​​​​​​​​​​​​​​​​Plants need to make their own food, so some of their cells contain chloroplasts Chloroplasts absorb light to make food (glucose) by photosynthesis

Prokaryotic and Eukaryotic Cells

There are two main types of cell: prokaryotic eukaryotic ​​​​​​​​​​​​​​​​​​​​​Plant, animal and fungal cells are all eukaryotic Bacterial cells are prokaryotic Prokaryotic cells are much smaller in size and: ​​​​​​​the genetic material is not enclosed in the nucleus the genetic material is a single DNA loop and there may be one or more small rings of DNA, called plasmids  they do not contain mitochondria or chloroplasts

Key Point:  Prokaryotic cells are much simpler in structure then eukaryotic cells. That id why scientists think that they developed before eukaryotic cells   Key Point: Plasmids have become very useful to scientists. They allow genes to be inserted into bacteria in genetic engineering.

A Typical Bacterial Cell

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Bacteria cells have many different shapes - some are round, some are rod-shaped and some are spiral - but they are all prokaryotic cells.  In bacterial cells, the roles of mitochondria and chloroplasts are taken  over by the cytoplasm. There may be one or more flagella, which are tail-like structures that move the bacterium, Plasmids are present, which are loops of DNA that can be transferred from one cell to another. Plasmids allow bacterial cells to move genes from one cell to another.

Caption: : A Typical Bacterial Cell