chemical elements and water the most frequently occurring elements in all living things: carbon...
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Chemical elements and water
The most frequently occurring elements in all living things:• Carbon (19%) • Hydrogen (10%) • Oxygen (65%) • Nitrogen (3%)
Other elements required in small amounts:
Sulphur (0.25%) Calcium (1.5%) Phosphorus (1%) Iron (0.7%) Sodium (0.15%)
The role of certain elements(S) In certain amino acids (cysteine and methionine), proteins form disulphide bonds(Ca) Found in bones and teeth, also involved in neurotransmitter release in synapses(P) Component of nucleic acids and cell membranes.(Fe) Found in haemoglobin (animals), allowing for oxygen transport(Na)Involved in the generation of nerve impulses in neurons
Structure of water molecules
Hydrogen is slightly positive
Oxygen is slightly negative
Hydrogen bonds between water molecules
Hydrogen bonds are weak.
Give an example of where this is
significant.
Special properties of water
Write 3 or 4 sentences for each of the properties of water:Thermal PropertiesCohesive PropertiesSolvent PropertiesOther Properties
The relationship between the properties of water and its use in living organisms as a coolant, medium for
metabolic reactions and transport medium
Outline this relationship using the following headings:
Coolant
Medium for Metabolic Reactions
Transport Medium