prokaryotic cells

what is the mesosome and what is its function?

• a tightly folded region of the cell membrane

• contains all the membrane-bound proteins required for respiration and photosynthesis

what is an adaptation of a mesosome and what is it involved in?

• folds inc surface area for respiration and photosynthesis

• involved in cell wall formation in cell division

what is a plasmid and what is its function?

• a small loop of DNA

• contains beneficial genes (e.g. antibiotic resistance) that can be passed between cells

• aren't always present in prokaryotic cells and some cells have more than one

what is circular/naked DNA?

a single loop of double-stranded DNA not associated with proteins (histones)

what is a capsule and what is its function?

• a thick polysaccharide layer outside of the cell wall

• used for/as:

  • sticking cells together

  • a food reserve

  • protection against desiccation (loss of moisture), chemicals and phagocytosis

what is a flagellum and what is its function?

a rigid rotating helical-shaped tail used to make the cell move

what is a ribosome and what is its function?

a small structure (70s) that synthesises proteins

what is the cell surface membrane made of and its function?

• made of lipids and proteins

• controls the entry and exit of substances (partially permeable)

what is the cell wall made from and what is its function?

• a physical barrier made from a polymer called murein (aka peptidoglycan)

• protects cell against mechanical damage and osmotic lysis (splitting of a cell)

what is peptidoglycan?

a glycoprotein - a polymer of polysaccharide chains and short peptides

how do prokaryotes reproduce?

through binary fission

what is the difference between the cytoplasm in a prokaryotic and eukaryotic cell?

prokaryotic cells' cytoplasm have no membrane bound organelles

what structures are always present in prokaryotic cells?

• cell surface membrane

• cytoplasm

• ribosomes

• DNA