Summary
Summary Plasma membrane transport
- Course
- Institution
Year 1 Biology AQA A level notes. Achieved an A* in my final exam using these notes. They are based on the mark scheme requirements.
[Show more]
Seller
Follow
arabellasherratt
Content preview
Plasma membrane transport summary notes01 November 2022 12:21
Transport by 5 different methods
Facilitated diffusion
- Occurs in channel proteins and carrier proteins
- Down a concentration gradient
- With polar water soluble substances or large insoluble substances that cannot pass
through the membrane between lipid molecules (as for polar water soluble, centre of
bilayer is hydrophobic so cannot pass through)
- Ie calcium through a calcium ion channel or alpha glucose in a glucose carrier protein
Simple Diffusion
- Down a concentration gradient
- With small lipid soluble molecules (therefore non polar molecules) that can pass thro
as can dissolve in bilayer
- Ie carbon dioxide out of cell or oxygen into cell
- Can move freely in membrane
Osmosis
- Pure water has a water potential of 0 kPa
- Solutions have a negative water potential
- The more concentrated the solution, the more negative the water potential will be
- Down water potential gradient
- With small molecules that can pass between phospholipid molecules (water)
- Can move in or out of the cell
- Osmosis- net movement of water across a biological membrane from a less negative
potential more negative water potential
- Plant cells - plasmolysed when the plasma membrane has peeled away from the polyb
cellulose cell wall - this means that water has left the cell from a less negative water po
the vacuole to a more negative water potential outside the cell
- Become turgid when water enters the cell from a less negative water potential outside
a more negative water potential in the vacuole
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 arabellasherratt. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.87. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75759 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now