3.1.7 and 8 water and other ions Flashcards
Give a property of water
polar, solvent, reactive
Why is it useful to living organisms that water is polar?
acts as a universal solvent
why is it useful to living cells that water is a solvent?
reactions occur faster in solution
why is it useful to living cells that water is reactive?
takes place in hydrolysis and condensation reactions
name an important ion
hydrogen, sodium, iron, phosphate
how do water and ions enter cells?
they can move down a concentration gradient
both move through channel proteins
ions can move against a concentration gradient by active transport
3 properties of water that are important in biology
Is a metabolite
Is a solvent
Has a (relatively)high heat capacity
Has a (relatively)largenlatent heat of vaporisation/ evaporation
Has cohesion / hydrogen bonds between molecule
What is meant by water having a high specific heat capacity (SHC)?
Hydrogen bonds in water require lot of heat energy to be broken
Therefore water can absorb a high amount of heat before its temperature rises
What is meant by water having a high latent heat of vaporisation (LHV)?
A lot of energy is required to evaporate one gram of water
Due to the presence hydrogen bonds between molecules
How is water a dipolar molecule?
Has a delta positive end on hydrogen atom and delta negative end on oxygen atom
What makes water a good solvent
Readily dissolves other substances
How is water a good metabolite
Breaks down molecules by hydrolysis
Produced in condensation reactions
Is a major subunit of photosynthesis
What’s the function of an Fe ion in Haemoglobin
Transports oxygen around the body to cells
What is the function of phosphate ions in the body
Structural component of DNA
Stores energy in ATP molecules
What is the function of hydrogen ions in the body
Determines the pH of solutions and therefore the functioning of enzymes
