Class notes
Lecture Notes
- Course
- Institution
Lecture notes of 10 pages for the course Membrane and Cellular Biochemistry at QMUL
[Show more]
1 review
By: betulalm • 3 year ago
Seller
Follow
fatima-attia
Reviews received
Content preview
Evolution of membrane complexity, lipid structures and membrane proteinsLearning objectives:
1. Understand the likely evolutionary pathways to the development of internal membrane systems in eukaryotic cells
2. Know basic structure of membrane lipids
3. Understand the different ways in which protein are attached to membranes and the characteristic structures of
membrane-integral proteins.
Evolution of membrane complexity
Scheme for evolution of the internal membranes of eukaryotic cells
There are no definite answer about evolution due to no fossil records.
Assume precursor cell has a membrane
There are 2 possible routes to acquire extra membrane to produce a cell with many internal membrane organelles:
- Route 1: invagination of the plasma membrane to increase the surface area
- Route 2: generate more membrane inside the cell by capturing cells
Mitochondria have 2 membrane (OMM & IMM)
Mitochondria started out as a bacteria
- How do we know? Sequence mitochondria DNA to get phylogeny, which revealed what sort of bacterium the
mitochondria was.
Mitochondria has own genome distinct from nucleus DNA
Mitochondria went through symbiosis with proeukaryote to produce a cell with mitochondria
- The same occurred with plant and algae cells with chloroplast
- Chloroplast has own DNA, which can be sequence to find type of bacterium
- Chloroplast has 3 membranes
Outer membrane
Inner membrane
Thylakoid membrane
Cyanobacterium is the precursor of chloroplast
Where did the OMM and Outer chloroplast membrane originate form?
- Some text book mention that the OMM started out as another invagination of the plasma membrane
, Step 1
- Invagination of prokaryote cell swallowed mitochondria
- Mitochondria started as a gram-negative bacterium (2
membrane; outer membrane & plasma membrane).
- Phylogenetic tree reveals that mitochondria came from a
gram negative bacteria
- Outer membrane of a gram negative bacteria contains a
class of proteins called porins.
- Outer membrane of mitochondria contains proteins
build in a similar way to porins but are not porins.
Mutated descends of porins with function
change
TOM = trasnslocon of the outer mitochondrial
membrane.
TOM function = import proteins encoded in the
nucleus and synthesised in the cytoplasm
- Mitochondrial matrix = cytoplasm of mitochondrial
that was once bacteria.
- Inner mitochondrial membrane = plasma membrane
of ancestral bacteria
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller fatima-attia. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.12. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
76669 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now