Class notes
cell membrane notes
These notes contain everything you need to know about the cell membrane. For more information about cell transport, check out the other document.
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
Seller
Follow
Content preview
Why are cells so small?- Surface area to volume ratio
- Allows water/nutrients to enter
- Allows waste to exit
- More surface area→slower diffusion
- Small volume, high surface area is best
- Diffusion limitations
- Things need to go from the outside to the inside
- Smaller in volume→less time for materials to enter
- Smaller in volume→waste leaves faster
- Waste removal: faster waste removal prevents build-up of toxicity
- Nutrient uptake: nutrients diffuse faster into the cell with less volume
Cell membrane
It is a structure that separates the inside of the cell from its environment, the outermost part of
the cell, surrounding it. All cells have cell membranes. It is selectively permeable, so it can
control what goes in and out.
Extracellular matrix (ECM) - space between the cells
Endocytosis: parts of the membrane surround materials, allowing them to enter
● Made of:
○ Lipids - mainly aid in the structure of the membrane
■ Mostly phospholipids
■ Also some cholesterol
○ Proteins - mainly work in transport and communication
■ Integral (transmembrane)
■ Peripheral
■ Glycoprotein (carb attached to protein): can make connections with other
cells, adhesion, helps in immune response
○ Carbohydrates - Usually found on the outside, attached to either proteins or lipids
(glycoproteins/glycolipids). Helps cells recognize each other (does it belong to my
body or not) - important for the immune system. Also provides protection/
cushioning for the membrane, and a physical barrier.
■ Glycoproteins can signal to other cells what kind of cell it is
(native/doesn’t belong)
● Constantly shifting ‘fluid mosaic’ to:
○ Allow nutrients to enter
○ Allow other materials to enter/move:
■ Oxygen, nonpolar - goes straight through phospholipids
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 em22. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
62774 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 15 years now