Summary
Summary PROKARYOTIC CELLS AND THE ENDOSYMBIOTIC THEORY
- Module
- Unit 2 - Cells
- Institution
- AQA
Notes on PROKARYOTIC CELLS AND THE ENDOSYMBIOTIC THEORY
[Show more]
Seller
Follow
Content preview
BY JHENICA UTHAYAKUMARANPROKARYOTIC CELLS
Prokaryotic cells are smaller than eukaryotic cells and have no nucleus or nuclear envelope. Even though they may lack some membrane-bound organelles,
prokaryotic cells share some of the same features as eukaryotic cells:
1) The plasma/cell membrane= this acts as a physical barrier which controls what enters and leaves the cell. Furthermore, it enables the cell to communicate
with its neighbours and surroundings.
2) The ribosomes = even though the ribosomes are smaller than those in eukaryotic cells they are still able to undergo protein synthesis as they are made of
protein and ribosomal RNA. They are involved in the process of translation, in which proteins are synthesised from messenger RNA.
3) Cytoplasm = the cytoplasm holds all the chemicals of the cell and is where chemical reactions take place. It contains water, proteins, and organic and
inorganic molecules.
4) Cell wall (present in some eukaryotic cells; plants cells etc.) = In prokaryotic cells, the cell wall is usually made up of peptidoglycan (murein). In bacteria,
the cell wall may also contain other proteins, depending on whether they are Gram-positive or Gram-negative. In both eukaryotic cells and prokaryotic
cells the cell wall provides strength and rigidity to the cell structure and is permeable to allow diffusion of solutes.
Other features of prokaryotic cells:
1) (Slime)Capsule = This outmost layer in a prokaryotic cell is made of thick polysaccharide, making it highly organised and not easily removed.
2) Circular DNA= These contain the genomic DNA of the cell.
3) Nucleoid region= The region of the cytoplasm that contains the circular DNA.
4) Flagella = Long, ‘whip-like’, rigid tails that rotate to help the cell move in its surroundings.
5) Pili = These can ‘fix’ the cell to a surface and can aid the exchange of genetic information between cells.
ENDOSYMBIOSIS
A type of symbiosis in which one symbiotic organism lives inside another.
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 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 juthayan21. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £3.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
78310 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now