Eukaryotic and Prokaryotic Cells

Eukaryotic and prokaryotic cells

• Plant cells and animal cells are eukaryotic. Fungal cells such as yeast, and protist cells, are eukaryotic too.
• Bacterial cells are prokaryotic.
• Prokaryotic cells are much smaller than eukaryotic cells.

How a prokaryotic cell differs

• A prokaryotic cell has no nucleus: its genetic material is DNA free in the cytoplasm.
• Its DNA is a single loop of DNA
• It has plasmids, small rings of DNA.
• It has no mitochondria.

A eukaryotic cell, compared with a bacterium:

• has a nucleus and mitochondria
• lacks a single loop of DNA and plasmids
• yeast also has a vacuole

Both cell types have cytoplasm, a cell membrane, ribosomes and genetic material. Write genetic material for what every cell contains.

Sub-cellular structures and their functions

• Never write the nucleus is the brain of the cell or the nucleus controls what enters and leaves the cell.
• Mitochondria release energy. Never write mitochondria produce energy, mitochondria make energy or mitochondria create energy, and never anaerobic respiration in mitochondria.
• Write controls for what the cell membrane does to substances moving in and out.
• The structure that makes a plant or algal cell green: chloroplast.

Plant cells and animal cells

• In plant cells but not animal cells: cell wall, chloroplasts, permanent vacuole.
• The plant cell wall is made of cellulose. Write cell wall for the structure.
• Algal cells also have a cell wall and chloroplasts.
• Fungal cells such as yeast also have a cell wall and a permanent vacuole.
• An animal cell drawn from a micrograph shows a nucleus, with labels such as nucleus, cell membrane, cytoplasm and mitochondria. Never draw a cell wall on an animal cell, or chloroplasts or a vacuole in an animal cell.