Lecture 13-16 Flashcards
______ was a Lichenologist- study of lichens (a symbiosis b/w cyanobacteria and fungi), and Proposed theory of symbiogenesis-symbiotic relationships between simple cells can lead to the evolution of larger, more complex cells.
Konstantin Mereschkowski
_____ Proposed that mitochondria were bacteria
Ivan Wallin
______ Proposed that some organelles had bacterial origins
Lynn Margulis
What is 1st primary endosymbiosis?
- host cell membrane, either bacteria pushed its way in or host started to engulf bacteria
- host cell mem starts to close around the bacterium and reform
- bacteria has its own mem still but the host mem as well
- if the relationship becomes permanent, bacteria has an inner mitochond. Mem which is bacterial like, and a outer membrane which will be host like
What is the Evidence to Support an Endosymbiotic Origin of Mitochondria?
size
Morphology /shape
Double Membrane
Structure (outter em, inner mem, folds (crista to increase SA), matrix (essentially the cytoplasm
True or False: Bacteria and mitochondria have similar size and morphology.
True
How do mitochondria replicate? Is it simlar to bacteria?
Mitochondria and bacteria divide by binary fission
They form a division plane and use FtsZ proteins
Mitochondria can only be formed from pre-existing mitochondria
Yes, similar to bacteria
What are the characteristics of mitochondrial DNA?
Mitochondria contain their own DNA
Mitochondrial DNA is circular bacterial origin
Mitochondrial DNA does not encode all of the proteins necessary for mitochondria to function
Mitochondrial DNA does not contain introns bacterial origin
Mitochondrial DNA does not undergo recombination (only change by mutation)
Mitochondria contain multiple copies of DNA
–lots of variability
How does mitochondrial replication work?
Origin of rep (transcript start)
-as transcription start so does translation
-look to do things quick not careful
Where does your mitochondrial DNA come from?
Mom
How is mitochondrial DNA used as a “clock”?
- direct ancestor that can be tracked
- origin in AFRICA (we started as ppl in africa)
- first migrations into asia and australia
- then into northern parts of asia into northern north america to central and south america
- also ppl from asia into pacific and then into south america
How does DNA barcoding work?
-used for identification
-attempting to build a large DNA data base so that the computer can be used in the field to scan DNA
Record info of what the organism is
Where it was found/ what time of yr
TISSUE SAMPLE
Sequence 1 of the genes of the genome (how is it same/ difference from other things in the database)
True or False: b/c all mitochond genome is coming from mother, if there is a bad allele often u won’t live past 4 or 5 yrs old
True
Parkinson’s, MS are examples of?
Mitochondrial disease
Prokaryotes and mitochondria have ______ ribosomes while eukaryotes have ______ ribosomes.
70s, 80s
True or False: ribosomes don’t operate by themselves there are accessory proteins that are used to help
True
In initiating amino acid of proteins Eukaryotes start with ______ and prokaryotes and eukaryotes ______
”ATG” = methionine , still has methionine within but start with “N-formyl”
What are the 5 complexes of the mitochondria electron transport chain
Complex 1- move protons from matrix to inter mem space
Complex 2- e- come in
Complex 3- takes in e- and pumps out protons into inter mem space
Complex 4- takes e- and protons with oxygen and makes water (moves protons from 1 side to matrix) high concentration of protons
Complex 5- ATP synthase = bring protons back over into the matrix but requires ATP in order to let them in
True or False: Mitochondria have programmed cell death
True
What are the key roles of mitochondria?
ATP synthesis coupled to electron transport
Translation of mitochondrial proteins
Iron-sulfur cluster biogenesis
Cell death
What is the nucleus first mitochondria later model?
Two prokaryote cells merge together and form a nucleus
Cell takes up a bacteria cell that becomes the mitochondria (3 partners technically)
WHat is the mitochondria co origin model?
Archaea and bacteria merge form eukaryotic cells that forms both nucleus and mitochondria (2 partners)
Why doesn’t antibiotics attack mitochondria?
1) access to cell
2) access to outer mitochondrial membrane
3) transporter – mutated – AB resistant
Missing
4) DNA target gene gone or mutated
5) RNA target gene gone or mutated
6) 1943- Antibiotic resistance –> selective pressure –> mitochondria
WHat are the 4 types of mitochondria like structure?
1 aerobic, 3 anaerobic (either everyone started anaerobic, and one evolved or vice versa)
Hydrogenosomes
- anaerobic, use pyruvate, not typical enzymes (TCA cycle), different electron transport chain (internal parasites, low oxygen)
Mitosome
- anaerobic, use pyruvate, not typical enzymes (TCA cycle), makes ethanol and acetate for ATP, not as efficient (intestinal parasites)
______ is an example of a species that has hydrogenosomes + and endosymbiotic methanogen
Nyctotherus ovalis
How does these different type of mitochondria like originate?
Alpha-protebacteria picked up by cell
Gene transfer and gene loss
A. Lose certain genes to environment (ie, TCA, electron transport) = hydrogenosome
B. no loss = mitochondria
C. Same as A but lose different set of genes to environment = mitosome
B loss of mitochondria, anaerobic takes its place
Gene loss = hydrogenosome
Different gene loss = mitosomal eukaryotic
What is most like mitochondria today?
Rickettsia
True or False: Photosystem I is older then Photosystem II
True
True or False: Only cyanobacteria uses both RC1 & 2
True
How does anaerobic photophosphorylation work?
Loss energy when passing electrons, gain energy from light (re-excited to high energy state) then transferred into high energy molecule (NADH)
How did both RC get into the same cell?
Loss of switch keeps both 1 and 2 together, both running at the same time
