Topic 1A : The Circulatory System Flashcards
Why is it important for water to be solvent
Substances can be transported more easily if they are dissolved in a solvent so water can easily transport all sorts of materials like glucose and oxygen around plants and animas=ls
Explain the structure of water
One atom of oxygen joined to two hydrogen atoms by shared electrons.
What makes water a dipolar molecule
The shared negative hydrogen electrons are pulled towards the oxygen atom causing the other side of each hydrogen with a slight positive charge
The unshared negative electrons on the oxygen atom give it a slight negative charge
Define dipolar
When a molecule has partial negative charge on one side and partial positive charge on the other side
How does the dipole nature of water make it good at transporting substances
This makes water cohesive and a good solvent
Explain how does water being cohesive contributes to being good at transporting substances
Water molecules tend to stick together which helps water to flow
Define cohesion
The attraction between molecules of the same type
Explain how does water being a solvent contributes to being good at transporting substances
Define mass transport
The bulk movement of gases or liquids in one direction, usually via a system of vessels and tubes
Give 4 features of mass transport systems
A system of vessels usually tubes which follow a specific route
A way of making sure substances move in the right direction
A means of moving materials quickly to meet the organisms needs
A transport medium usually water which carries dissolved substances
Give 3 advantages related to mass transport systems
Help to bring substances quickly from one exchange site to another
Help maintain concentration at exchange sites
Ensure effective cell activity by keeping the immediate fluid environment of cells within a suitable metabolic range
