all details about organelles

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Published on 25 Jun 2011
School
UTSC
Department
Biological Sciences
Course
BIOB10H3
Professor
StructureDescription Function ProteinsTargeting
Sequence
Chloroplast- arose from phagocytosis
of photosynthetic bacteria
- can divide by fission
- in plants, eukaryotic
alga, some protists and
prokaryotes
- Site of
photosynthesis
- uses energy and
sugar (aerobic)
- 90% of proteins are encoded by
nuclear DNA many proteins must
be imported (targeted) to
chloroplasts
- translated on free ribosomes in the
cytosol
Transit peptide @
amino end
Thylakoid Sacs (Internal
Membrane System)- membranous sacs
- arranged into grana
(stacks of thylakoid sacs)
- membrane has 75:25
protein lipid ratio
-have lumen inside
(electrochemical gradient
for light-dep rxn)
- thylakoids contain
chlorophyll - on thylakoid membrane, are
encoded by chloroplast genes
- ribosomes assemble on thylakoid
membrane (like RER) & stop
transfer sequence retains proteins in
the membrane
- has thylakoid
transfer domain
(thylakoid proteins)
Stroma Lamellae,
Stroma Thylakoid
(Internal Membrane System)
- flattened membrane
structure- attach to grana
- connect thylakoids
from different grana
Stroma - Matrix- Site of dark
reactions
- contains DNA,
ribosomes, tRNA to
encode for 100 genes
- has stroma-
targeting domain
(stroma proteins)
Outer envelope
membrane Contain porin proteins
(large channels)
- porin: bacteria protein
evidence of phagocytosis
Allow very large
molecules through
Inner envelope
membrane - Very impermeable
- require transporters
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Mitochondria
Nobel Prize 2009: proteins
are completely translated on
free ribosomes in cytosol
Mitochondrial diseases:
mutations from mt-DNA
inherited maternally (egg
supplies mitochondria)
Muscle Disorders: congenital
muscular dystrophy,
myopathies/
cardiomyopathies
Parkinsons, maple syrup
disease
- arose from phagocytosis
of aerobic prokaryote
- mitochondrial fission
- has own ribosomes
- in muscle, liver, fat,
plant cells, and sperm
- ATP production (cellular
respiration by extracting
energy from macromolecules
like glucose
- mitochondrial function
requires nuclear gene
products and these
proteins must be
imported (targeted) to
mitochondria
Inner mitochondrial
membrane (IMM)- cristae (folds) for more
SA (for more proteins)
- 75:25 protein lipid ratio
- lipid=cardiolipin:
unique phospholipid also
found in many bacterial
membranes
- very impermeable
- require 100 different
channels and pump
proteins including
proteins for ETC
- site of H+ build-up for ETC
- site of ETC
Internal sequence &
stop transfer sequence
for integral IMM, ETC,
and ATP synthase
proteins
Outer mitochondrial
membrane (OMM)- 50:50 protein lipid ratio
- contain porin proteins
(large channels) to allow v.
large molecules through
- porin: bacteria protein
evidence of phagocytosis
Matrix- gel-like from high
[protein]- contains DNA, ribosomes,
tRNA to encode for 37 genes mitochondrial
presequence @ amino
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Document Summary

90% of proteins are encoded by nuclear dna  many proteins must be imported (targeted) to chloroplasts. Translated on free ribosomes in the cytosol. On thylakoid membrane, are encoded by chloroplast genes. Ribosomes assemble on thylakoid membrane (like rer) & stop transfer sequence retains proteins in the membrane. In plants, eukaryotic alga, some protists and prokaryotes. Arranged into grana (stacks of thylakoid sacs) Have lumen inside (electrochemical gradient for light-dep rxn) Contains dna, ribosomes, trna to encode for 100 genes. Has stroma- targeting domain (stroma proteins) www. notesolution. com. Nobel prize 2009: proteins are completely translated on free ribosomes in cytosol. Mitochondrial diseases: mutations from mt-dna  inherited maternally (egg supplies mitochondria) In muscle, liver, fat, plant cells, and sperm. Atp production (cellular respiration by extracting energy from macromolecules like glucose. Mitochondrial function requires nuclear gene products and these proteins must be imported (targeted) to mitochondria. Lipid=cardiolipin: unique phospholipid also found in many bacterial membranes.