BRAINCAKEChemistry for Life
Revision notes for Chemistry for Life in Edexcel Biology (8BI0). Read the start of any lesson here, then sign in free for the whole lesson, the R.E.C.I.P.E. recall steps and the quiz.
- Ionic BondingIonic bonding happens when one atom transfers one or more electrons to another atom.
- Covalent BondingA covalent bond is a shared pair of electrons between two atoms.
- Important AnionsInorganic ions are needed by all organisms in small amounts, but each has specific roles.
- Important CationsCations are positively charged ions.
- WaterA water molecule, H2O, has two hydrogen atoms joined to one oxygen atom by covalent bonds.
- Water as a Polar SolventWater is often called the universal solvent because so many substances dissolve in it.
- Water as a Transport MediumTransport systems in animals and plants move substances in solution, and water is the liquid that does the carrying.
- Water as a HabitatMuch of Earth's life lives in water: oceans, rivers, lakes and ponds.
- Water in Plant Transport SystemsPlants move water from the roots to the leaves through xylem vessels: long, hollow tubes made of dead cells with no end walls, whose walls are…
- Water in Hydraulic MechanismsLiquid water is almost incompressible: squeezing it hardly reduces its volume.