Summary
Exchange of Substance summary pages
- Institution
- AQA
Unit 3: Exchange of substances summary pages for AQA A level biology
[Show more]
Seller
Follow
Content preview
Exchange ofSubstances
Introduction
● Importance: Living organisms require the exchange of substances with their
environment for various physiological processes.
● Surface Area to Volume Ratio:
● Cells and organisms need to maintain an adequate surface area to
volume ratio for efficient exchange.
Surface Area and Volume
● Surface Area:
● Determines the rate of exchange.
● Larger organisms have adaptations to increase surface area.
● Volume:
● Determines the metabolic rate.
● Smaller organisms have a higher surface area to volume ratio.
Gas Exchange in Single-Celled Organisms
● Simple Diffusion:
● Oxygen and carbon dioxide exchange directly through the cell
membrane.
● Limited by the surface area of the cell.
Gas Exchange in Insects
● Tracheal System:
● Network of tubes (tracheae) for direct air exchange.
● Spiracles control the entry of air.
● Adaptations:
● Thin, moist epithelium for efficient gas exchange.
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 rebekahhald. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £6.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
61001 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