Cells

Prokaryotic Cell

• plasmids: small circular DNA molecules

• ribosomes

  • split into two pieces (large and small)

• don't have "organelles"

• plasma membranes fold in on themselves

• simplified ???

• cytoskeleton = "cell" "skeleton"

  • helps cary out cell division

• cytoplasm

  • where everything floats in the cell

• cell walls

  • (bacteria has cell walls as well)

• flagella

  • extracellular structure
  • rotates to propel the cell through water

• fimbriae

  • extracellular structure
  • attaches to surfaces
  • establishes infections

Eukaryotic Cell

• much larger than prokaryotic cells

• cytoplasms are compartmentalized into several organelles

• nuclear envelope

  • pore-like
  • allows things to pass through

• nuclear lamina

  • maintains shape

• nucleolus

  • rRNA synthesis

• ribosomes

  • not actually organelles (because they are not membrane bound)
  • free ribosomes: made and used inside the cell
  • bounded ribosomes: made inside the cell but used outside the cell

• endoplasmic reticulum

  • rough ER: protein synthesis
  • smooth ER: lipid synthesis / breakdown

• pH in cells is normally 7.2

• vacuoles

  • used for water storage
  • filled with defensive chemicals

• peroxisomes

  • oxidations / reduction reactions
  • breaking down hydrogen peroxides