No Nucleus definite nucleus; DNA
present but not separate
from the rest of the cell
Prokaryotes
No Mitochondria; enzymes for
oxidation are on plasma
membrane
Prokaryotes
No Endoplasmic
reticulum
Prokaryotes
No chloroplasts; photosynthesis
localized in chromatophores
Prokaryotes
Present (70s): 50s & 30s
Prokaryotes
Present (80s)
60s & 40s
Eukaryotes
Both present in prokaryotes and eukaryotes
Cell membrane
Two great classes of organisms
– to understand life in molecular terms.
BIOCHEMISTRY
Parts of The Prokaryotic Cell
– Structures and
genetic information
in the form of one
or more DNA are
suspended in it
Cytosol
– Aid in attaching the
organism to other
cells or surfaces
– Molecular
machinery for
protein synthesis
Ribosomes
– Enable cells to swim
composed of
two layers of
phospholipid
molecules
interspersed
with cholesterol
and proteins
The Eukaryotic Cell
Plasma membrane
Membranesurrounded
structures lying
within the
surrounding
cytoplasm
The Eukaryotic Cell
Organelles
The PLASMA MEMBRANE
The PLASMA MEMBRANE
The selective permeabilities for ions
and substrates are provided by:
– transporters and
– ion channels
Specific proteins involved in facilitated
diffusion and active transport
TRANSPORTERS
“PING” STATE
“PONG” STATE
– Moves one type of molecule
bidirectionally
UNIPORT SYSTEM
– Moves two solutes in the same direction
SYMPORT SYSTEM
– Moves two molecules in opposite
directions (Na+ in, Ca++ out)
ANTIPORT SYSTEM