100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Summary Unit 2 - Cells Cell Membrane £3.39   Add to cart

Summary

Summary Unit 2 - Cells Cell Membrane

 15 views  0 purchase
  • Institution
  • AQA

Unit 2 - Cells Cell Membrane

Preview 1 out of 3  pages

  • June 24, 2023
  • 3
  • 2022/2023
  • Summary
All documents for this subject (280)
avatar-seller
ramiriam
Cell Membrane
Divides the cell into a barrier between the cytoplasm and the organelle
Regulates transport of materials in and out of cells
Has receptors to detect hormones/chemicals - cell recognition
Holds the components of some materials (chlorophyll)
Provides an internal transport system
Provides surfaces where reactions can occur
Isolates enzymes which may cause damage to cells (lysosomes)
The cell membrane has a fluid mosaic model.
Fluid - the individual phospholipid molecules can move making the membrane flexible.
Mosaic - the proteins imbedded in the bilayer are different in size shape and pattern.
The phospholipids form a continuous bilayer which is fluid due to the phospholipids which are
always moving. It doesn't allow molecules that are:
not lipid soluble
repelled by charge (if they are the same charge as the proteins channels they are repelled)
too large
is polar (hydrophobic molecules pass) and is electrically charged (difficulty passing
through the non-polar hydrophobic tails)




Phospholipid Molecules: a double (lipid bilayer) made up of a hydrophilic head which on both
layers points outside the cell membrane as it is attracted by water on both sides and
hydrophobic fatty acid tail which point to the centre of the membrane as it is repelled by water
on both sides. Phospholipids allow lipid soluble substances to enter and leave the cell, prevents
water soluble substances from entering and leaving and makes the membrane flexible.
Cholesterol: gives the membrane stability and a type of lipid which fits in between
phospholipids binding to the hydrophobic tails causing them to pack close together which

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

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

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

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 ramiriam. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £3.39. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

80364 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

Start selling
£3.39
  • (0)
  Add to cart