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Ch. 6 The Chemistry of Life
Ch. 6.1 Outline Atoms and Their Interactions
A. Elements – all matter (anything that takes up space and has mass) is composed of elements
1. Natural elements in living things
a). 96% of a human is C, H, O, N
2. Trace elements – (pg. 146) small amounts of elements that play a vital role in healthy cells. Ex: Fe, Mg, F, I
B. Atoms: The Building Blocks of Elements – elements are composed of atoms
a). atom 1. The structure of an atom –
a). nucleus –
b).
atomic parts
i. Neutron (N)
ii. Proton
iii.Electron
charge
location
mass
c). Electron energy levels – electrons move rapidly around atoms, forming electron clouds that have
several energy levels
i. Each Periodic Table Row = an energy level
Ex: C
C. Isotope of an Element
a). isotope–
Ex: C-14 vs. C-12: C-14 is radioactive, unstable and breaks down
b). Used in medicine- radiation kills cancer cells
1. Ex: Cobalt isotope used to treat cancer (p. 148)
D. Compounds and Bonding
a). compound –
1. How covalent bonds form – a bond between 2 non-metals who combine electrons to fill their valence shell.
a). Covalent bonds –
2. How ionic bonds form
a). Ionic bonds
E. Chemical Reactions.
1. Writing chemical equations
a). Products
b). Metabolism
Reactants
F. Mixtures and Solutions – when substance mix together but do not combine chemically.
1. Important mixtures: most organisms are composed of 70% water
a). Mixture- A combination of substances in which the individual components retain their own properties
Ex: sugar and sand
b). Solution –
c). Solute –
d). Solvent –
e). Soluable –
2. Acids and bases – the pH scale – measures hydrogen ion concentration
Ch. 6.2 Water and Diffusion
A. Water’s Importance- movement, transport…life
1. Water is Polar Molecule- a molecule with an unequal distribution of charge
1. Acts like a tiny magnet
2. Hydrogen bond –
2. Water resists temperature changes
1. Water must gain or lose a lot of heat to boil or freeze (ex: oceans do not freeze)
3. Water expands when it freezes (most liquids contract)
1. Density = mass/volume
2. Ice (below 1g/ml) is less dense than water (1g/ml)
B. Diffusion – movement across concentration gradient
1. Brownian motion – random movement of molecules
2. Diffusion process – slow process of equalization between concentrations
3. Results of diffusion
1. Dynamic equilibrium
4. Diffusion in living systems
1. Oxygen and Carbon dioxide exchange in the capillaries of the lungs and blood vessels
2. Movement in and out of cells
Ch. 6.3 Life Substances
A. Carbon’s Role
a. C can form 4 covalent bonds
b. Bonds to many things and itself
i. Single bond (alkanes) ex:
C
C
ii. Double bond (alkenes)ex:
C
C
iii. Triple bond (alkynes)ex:
C
C
1. . Molecular Chains- Carbon can form large molecules
1. Monomers2. Polymers 3. Condensation Reaction: makes polymers and water
4. Hydrolysis reaction: breaks down polymers
a). Hyrdo = water,
lysis = to break
5. Carbohydrates6. Sugars are carbohydrate
a). Monosaccharides –
b). Polysaccharides –
7. Lipids- (fats, oils, waxes)
a). Structure: glycerol and fatty acids (E-shaped)
b). Saturated fatty acids (S=single bonds)
c). Unsaturated fatty acids (at least 1 doulbe bond)
8. Protiens- built by amino acids - building blocks
a). 20 kinds of amino acids
b). Enzymesc). Peptide bond – covalent bond formed between amino acids
9. Nucleic Acids (composed of nucleotides)
a). Carry genetic info
b). Nucleotide = phosphate, sugar and Nitrogen base
c). 2 major kinds
1. RNA
2. DNA