Peroxisome, Mitochondrion, Lysosome Flashcards
Peroxisome
break down of long chain fatty acids and ether synthesis
Long chain fatty acid break down
via beta oxidation
releases H2O2 which is broken down via peroxidase
ether synthesis
makes plasmologen which is used by oligodendrocytes to make myelin (brain. leads to neurologic defects)
backbone for lipid membrane
DAB
diaminobenzadine
stains peroxisome by being taken in via enzyme with H2O2
leads to brown precipitate and is very electron dense so shows up as dark spot in peroxisome
regulation of peroxisomes
increase and decrease according to the needs of the cell
when more peroxisome is needed, genes are transcribed and protein is made. protein then fuses with existing peroxisome and that peroxisome multiplies
number of peroxisomes and size can be controlled in cell
PTS1
peroxisome targeting signal #1
serine-lysine-leucine sequence on C’ terminus of any protein will tag that protein for transport to peroxisome
PPARs
peroxisome proliferator activated receptor
FFA will bind to FABP and enter the nucleus which will then bind to PPAR
RA will bind to RXR (retinoid acid receptor) and interact with PPAR which will then sit on PPRE (peroxisome proliferator response element) and alter transcription of genes downstream
Exercise will upregulate PPARS
PDK4
Pyruvate dehydrogenase lipoamide kinase isozyme 4
through exercise, PPARs will bind to FFA and increase uptake of FFA into the cell
Also will turn on production of PDK4 which will inhibit utilization of glucose and burn FFA as source of energy in mitochondria
CD36
allows FFA to enter into cell (relevant when exercising and muscle cells want to burn lipids instead of glucose through PPAR pathway)
PEX
proteins responsible for importing enzymes into peroxisome
will bind to any protein that has PTS (serine-lysine-leucine at C’ terminus) and bind to membrane of peroxisome and go inside
x-linked
transporter of long chain fatty acids
PTS1
bind to PEX5
PTS2
bind to PEX7
signal at N terminus of protein but signal is not as conserved (not as specific)
x- linked adrenoleukodystrophy
increase in very long chain FFA in blood
restrict diet and use lorenzo’s oil
mitochondria
powerhouse!
intermembrane space
in mitochondria between inner and outer membrane
ionically and pH wise same as cytosol so as to allow ions to flow freely in and out of membrane
inner matrix
space within inner membrane
location of mitochondrial DNA and have ribosomes to make mitochondrial proteins
cristae
invaginations in mitochondria
inner membrane
impermeable die to specialized membrane lipids
not even proton can pass
causes pH of inner matrix to be alkaline
How is ATP formed in mitochondria
through H+ gradient
H+ are pushed out through the electron transport chain (using energy in electron) into intermembrane space (creates electrochemical gradient between matrix and inner membrane space) where the H+ will go back down through the ATP synthase to turn ADP into ATP
acidification of endosome and lysosome
ATP synthase rotor moves in reverse and burns ATP to move H+ out of matrix
mitochondrial size
changes via fusion or fission
lysosomes
acidic vesicles in the cytoplasm full of hydrolytic enzymes
pH 4.5-5
function of lysosome
hydrolyze all macromolecules to momeric subunits and recycle subunits via transmembrane transport to cytoplasm
hydrolase
require acidic environment and are inactive outside lyososome
how are vesicles brought into lysosome?
through endosome
tagging protein for transport to lysozyme
tagged by M6P (mannose 6 phosphate) will bind to receptor in trans Golgi which is then packaged into vesicle and directed to early endosome which is becoming acidic via ATP pump
the lower pH- enzyme will let go of receptor and receptor will be shipped back to golgi
over)
lysosomal storage disease
problems in protein transport will lead to disease which will result most often neurologically- the material needing to degrade will build up because of no turn;
either due to lack of lysosomal enzymes or lack of enzymes needed to tag
I cell disease
inclusion cell disease, also known as mucolipidosis II
defective glcnac phosphotransferase which is used to tag enzymes to enter into lysosome
death by age 7; developmental delays; hepatomegaly, cognitive delay
hepatomegaly
enlarged liver; in I cell disease it is because stuff is not getting degraded
autophagosome
mitochondrial death
