lecture 7 - Part II Flashcards
semiatonomous organelles
can grow and divide to reproduce themselves
example of semiautonomous organelles
mitochondria and chloroplasts
mitochondria
power plant of the cell
sites of aerobic respiration
converts food energy into a form of energy cells can use to power their reactions
contain their own DNA
inner membrane of mitochondria
convoluted with unfolding called crusted
large surface area that enhances productivity
where does ATP occur
on the crista
many steps of cellular respiration occur on the matrix
chloroplasts
member of a family of organelles called plastids
contains green pigment chlorophyll also enzymes and other molecules that function in photosynthesis
role of chloroplasts
capture light and energy and use some of the energy to synthesize organic molecules
what are the two reasons why mitochondria and chloroplasts are not apart of the edomembrane system
membrane proteins are not made by the ER bur rather ribosomes in the cytosol and their own ribosomes
each contains a small amount of DNA that codes for a small number of proteins within these organelles
endosymbiont theory
mitochondria in eukaryotic cells are thought to derive from bacteria like endosymbionts
what is the evidence that supports the endosymbiotic origin of plastids and mitochondria
- inner membranes of both have enzymes and transport systems that are similar to the plasma membranes of modern prokaryotes
- both replicate by splitting similar process to binary fission
- each organelle has a single circular DNA molecule
- these organelles contain trans, ribosomes and other molecules needed to translate DNA into protein
- ribosomes in mitochondria and plastids are similar to prokaryotic ribosomes in many ways
serial endosymbiosis
all eukaryotic cells have mitochondria
not all eukaryotes have chloroplasts
what is the hypothesis of serial endosymbiosis
supposes mitochondria evolved before plastids
non membranous organelles
ribosomes
nucleolus
centrioles
cytoskeleton
ribosomes
produced by nucleolus
present on rough ER
where protein molecules are assembled
nucleolus
located within the nucleus
main function of nucleolus
the production and assembly or ribosomes components
cytoskeletal
eukaryotic cells have a wide variety of distinct shapes and internal organization
cells are capable of changing their shape moving organelles
this requires a network of proteins placed in the cytoplasm known as cytoskeleton
what is the cytoskeleton composed of
microtubules
intermediate filaments
microfilaments
microtubules
cylindrical tubes
composed of polymers of a and b tubulin
functions of microtubules
shaping the cell
structures used for movement
inter/intra cellular transport
separating chromosomes