Cells
Eukaryotic cell structure
Cell surface/plasma membrane
-selectively permeable → controls exchange of substances in and
out of cell
-has receptor molecules to respond to chemicals like hormones
-channel proteins enable movement of ions/large/polar molecules
-mainly phospholipids and embedded proteins
-bilayer
Nucleus
-surrounded by nuclear envelope (double membrane)
-nuclear pores allow larger molecules through (e.g RNA)
-contains linear DNA
-contains one or more nucleoli → makes rRNA and ribosomes
-seperates genetic material from cytoplasm activity
Endoplasmic reticulum
-stack of flattened fluid filled membranes called cisternae
-connected to outer membrane of nucleus
-RER has ribosomes on outer membranes → makes proteins on
ribosomes and packs them into vesicles
-SER has no ribosomes → makes,stores and transports lipids and
carbs
Golgi apparatus
-stack of flattened fluid filled membranes
-makes lysosomes (vesicles containing enzymes)
-modifies proteins and lipids from ER + labels them so they are
sent to right destination
-transported in golgi vesicles
-vesicles may fuse with cell membrane and release contents
inside cell
Lysosomes
-membrane bound
-Can contain digestive enzymes (e.g. proteases)
-Can contain lysozymes (enzymes that destroy bacterial cell walls or those such
, as acrosomes in head of sperm cells to helps it penetrate the egg)
-hydrolyse material ingested by phagocytes
-destroy material around cell
-digest worn out organelles/cells
Ribosomes
-larger in eukaryotes
-float free in cytoplasm or bind to ER
-2 subunits
-each made of rRNA
-site of protein synthesis
Mitochondria
-double membrane
-inner membrane folded to form cristae
-central part is matrix (contains enzymes involved in respiration)
-site of last stage of respiration
-therefore produce ATP
Chloroplast
-double membrane around fluid filled space called storms
-storms contains stacked membrane bound sacs called grana
—> within thee, the LDR occurs in the thylakoid membrane
while LIR takes place in the stroma
-thylakoids are flattened,fluid filled sacs within the stroma
-stroma also contains starch grains for temporary storage of
glucose and ribosomes for protein synthesis
Viruses
-no ribosomes,plasma membrane or cytoplasm
-dont carry out respiration,protein synthesis etc.
-virus is inert (doesnt need ATP) when on outside of cell
Viral structure
-lipid envelope in some viruses (made of lipoproteins)
Eukaryotic cell structure
Cell surface/plasma membrane
-selectively permeable → controls exchange of substances in and
out of cell
-has receptor molecules to respond to chemicals like hormones
-channel proteins enable movement of ions/large/polar molecules
-mainly phospholipids and embedded proteins
-bilayer
Nucleus
-surrounded by nuclear envelope (double membrane)
-nuclear pores allow larger molecules through (e.g RNA)
-contains linear DNA
-contains one or more nucleoli → makes rRNA and ribosomes
-seperates genetic material from cytoplasm activity
Endoplasmic reticulum
-stack of flattened fluid filled membranes called cisternae
-connected to outer membrane of nucleus
-RER has ribosomes on outer membranes → makes proteins on
ribosomes and packs them into vesicles
-SER has no ribosomes → makes,stores and transports lipids and
carbs
Golgi apparatus
-stack of flattened fluid filled membranes
-makes lysosomes (vesicles containing enzymes)
-modifies proteins and lipids from ER + labels them so they are
sent to right destination
-transported in golgi vesicles
-vesicles may fuse with cell membrane and release contents
inside cell
Lysosomes
-membrane bound
-Can contain digestive enzymes (e.g. proteases)
-Can contain lysozymes (enzymes that destroy bacterial cell walls or those such
, as acrosomes in head of sperm cells to helps it penetrate the egg)
-hydrolyse material ingested by phagocytes
-destroy material around cell
-digest worn out organelles/cells
Ribosomes
-larger in eukaryotes
-float free in cytoplasm or bind to ER
-2 subunits
-each made of rRNA
-site of protein synthesis
Mitochondria
-double membrane
-inner membrane folded to form cristae
-central part is matrix (contains enzymes involved in respiration)
-site of last stage of respiration
-therefore produce ATP
Chloroplast
-double membrane around fluid filled space called storms
-storms contains stacked membrane bound sacs called grana
—> within thee, the LDR occurs in the thylakoid membrane
while LIR takes place in the stroma
-thylakoids are flattened,fluid filled sacs within the stroma
-stroma also contains starch grains for temporary storage of
glucose and ribosomes for protein synthesis
Viruses
-no ribosomes,plasma membrane or cytoplasm
-dont carry out respiration,protein synthesis etc.
-virus is inert (doesnt need ATP) when on outside of cell
Viral structure
-lipid envelope in some viruses (made of lipoproteins)
