1. Chemistry of Life
Chapters 4 & 5

2. BIOSPHERE
ECOSYSTEM
COMMUNITY
POPULATION
ORGANISM
ORGAN SYSTEMS
ORGANS
TISSUES
CELL
MOLECULE
ATOM

3. MATTER: MADE OUT OF ATOMS
Matter made out of the same kind of atom is known as an ELEMENT
There are 25 elements that are present in living organisms
The four main ones are: Oxygen, Nitrogen, Carbon & Hydrogen
Compounds are two or more elements chemically combined in a fixed ratio

5. What is an ATOM?

6. SUBATOMIC PARTICLE
CHARGE
MASS (in relation to other particles)
LOCATION IN ATOM
PROTON
NEUTRON
ELECTRON
Generally, same number of protons as electrons
When the number of Protons changes, the kind of atom changes
Generally, the same number of protons as neutrons. If number of neutrons is greater than protons, then the atom is called an isotope

7. Periodic Table of Elements

8. Isotopes of Carbon

11. Electrons and bonding
The number of electrons in the outer shell determines how an element will react with another
Elements want to have “full” outer shells
To have a full outer shell an element will either share or transfer electrons
Ionic Bonding: elements transfer electrons
Covalent Bonding: elements share electrons

12. Ionic Bond

15. Elementary sodium reacts strongly with water, according to the following reaction mechanism:
2Na(s) + 2H2O → 2NaOH(aq) + H2(g) A colourless solution is formed, consisting of strongly alkalic sodium hydroxide (caustic soda) and hydrogen gas. This is an exothermic reaction. Sodium metal is heated and may ignite and burn with a characteristic orange flame. Hydrogen gas released during the burning process reacts strongly with oxygen in the air. A number of sodium compounds do not react as strongly with water, but are strongly water soluble.
Read more:

16. Ions When an atom loses or gains electron(s), the atom becomes an ion
If it loses electrons, it becomes positively charged
If it gains electrons, it becomes negatively charged

17. Chemical Bonds Ionic bonds → TRANSFER of electrons
Covalent bonds → SHARING of electrons

18. Chemical Reactions
In a chemical reaction the atoms of the reactants are rearranged to form the products of the reaction
REACTANTS PRODUCTS
ENERGY
ENDOTHERMIC EXOTHERMIC

21. The structure of water
Why is water such a unique substance?

22. WATER MOLECULE

24. Water structure

25. Water Properties
COHESION
ADHESION

26. Implications of Property in Nature
Properties of water
Meaning
Implications of Property in Nature
Cohesion
Adhesion
Temperature Moderation
Density of Ice
Universal Solvent

27. In your group, read Water’s Life Supporting Properties section in your book (pp 82-84)
Each person is reading and filling on the table the info for one or two of the properties

28. Implications of Property in Nature
Meaning
Implications of Property in Nature
Cohesion
Water molecules stick together due to H bonds
Small animals may walk on water
Adhesion
Water molecules stick to other molecules
Capillary action.
Water pulled to top of trees
Temperature Moderation
Water makes it so changes in temperature do not happen quickly
Animals can gradually change their internal system with changes in water temperature
Density of Ice
Ice is less dense than water so it floats
Ice insulates organisms living beneath
Universal Solvent
Many compounds dissolve in water
Dissolved compounds can be brought to cells (via sap or blood) or move about cell cytoplasm

29. pH scale

31. ACID compounds donate H+ ions to a solution (HCl)
BASE compounds donates OH- ions to a solution (NaOH)
BUFFERS cause a solution to resist changes in pH

33. BIOMOLECULES
What is the main chemical element present in all biomolecules?

35. ORGANIC COMPOUNDS: Carbon based
INORGANIC COMPOUNDS: Non-carbon based

36. Molecules of life
Carbohydrates
Lipids
Proteins
Nucleic Acids

37. Notes Monomers – smallest unit of polymer
Polymer – Long chain of monomers linked together

38. Notes Carbohydrates: Organic compound made up of sugar molecules
Monosaccharides – one sugar unit
Disaccharides – two sugar units
Polysaccharides – long chains of sugar units

39. Notes on Lipids Lipids – Water-avoiding molecule (hydrophobic)
Two types of lipids:
Fats – Three long fatty acid chains attached to glycerol molecule (saturated or unsaturated)
Steroids – lipid molecule form of four fused rings (testosterone, estrogen & cholesterol)

40. NOTES ON NUCLEIC ACIDS
Nucleic Acid: A large molecule made up of smaller molecules called nucleotides.
Nucleotides: Small molecules made up of a sugar, a nitrogen base, and phosphate
Nucleic acids are what our DNA or genetic material is made of
With out nucleic acids our body would not have directions and could not function.

41. NUCLEOTIDE

42. Notes on Proteins
Proteins are made in cells by linking amino acids together to form polypeptide chains
There are only 20 different amino acids
Proteins are composed of one or more polypeptide chains
The order of amino acids in polypeptide chains, and the three-dimensional shape of a protein molecule determines its function

43. Protein Shape
The long Amino acid chain folds to make the protein useable
A proteins shape is changed by its surroundings
A protein that is outside of its normal environment will be denatured (misshapen)

44. Notes on Enzymes An enzyme is a type of protein
Each enzyme is specific to a kind of chemical reaction
Enzymes are able to speed up chemical reactions in living cells by lowering the activation energy of the reaction
Enzymes are affected by pH and temperature

45. Enzymes