1) Properties of Water
Water is a polar covalent solvent
•Oxygen end is slightly negative•Hydrogen ends are slightly positive QuickTime™ and a
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Hydrogen Bonding• Polarity of water
allows attraction between other water molecules– Hydrogen bond - attraction
between hydrogen and another highly electronegative atom (FON)
– Weaker than covalent or ionic bonds
– Water is unique in that one molecule can form up to 4 hydrogen bonds.
Properties of Water
Cohesion: attraction between 2 molecules of same substance
Adhesion: attraction between 2 different molecules
-Capillary action - forces between molecules cause water levels to rise against gravity (One way plants draw water from their roots).
Solutions and Suspensions
• Solution: Type of mixture with components evenly distributed. – Solute: What is dissolved.– Solvent: Substance which
solute is dissolved in (usually water).
– Like dissolves like!
Suspension: Mixture in which material will not dissolve
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Acids, Bases, and pH
• Water can ionize:H2O H+ + OH-
• pH Scales measures the concentration of Hydrogen and Hydroxide ions in solution.
– Ranges from 0 to 14
– pH of 7 is neutral (H+ = OH-)
– pH less than 7 is considered acidic (H+ > OH-)
– pH greater than 7 is called basic (H+ < OH-)
– Each value on the pH scale is a a factor of 10!» pH of 3 vs. pH of 5, the pH of 3 has 100 times more hydrogen ions!
Acids and Bases
• Acids are compounds that produce H+
ions in solutions.
• Bases are compounds that produce OH- in solution.
• *Buffers are weak acids or bases that can react with strong acids/bases to prevent sharp changes in pH.
2) Organic Compounds
• Organic Chemistry refers to the study of carbon compounds. – 1) Carbon atoms have 4 valence electrons,
and can form 4 individual covalent bonds.– 2) Carbon can bond with itself (single,
double or triple covalently), creating the possibility of huge chains.
– Polymerization - the formation of large molecules from smaller components.
4 Major Organic Components of Life
• 1) Carbohydrates: – Contain C, H, O in a ratio of
1:2:1.– Main source of energy.– Short and long term storage– Name ends in -ose
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1) Carbohydrates– Monosaccharides: single molecule sugars
• Glucose, Fructose, Galactose
• Chemical Formula C6H12O6
– Disaccharides: double sugars
• Maltose, Sucrose, Lactose
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How do macromolecules form?
• Dehydration synthesis!– Through a reaction of two molecules and energy,
water is produced.
– The reverse is known
as Hydolysis
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Carbohydrates
• Polysaccharides: 3 or more simple sugars bonded together.– A) Starch main form of energy storage for plants. – B) Glycogen (Animal starch) form of storage in
animals.– C) Cellulose chains of glucose formed in plants for
support structures. – D) Chitin is a polysaccharide that makes up
exoskeletons of many insects.
2) Lipids - oils, fats, waxes
• Contain C, H, O (H:O ratio is greater than 2:1 so lots of Hydrogen!)
• Used for long term energy storage (fat tissue)
• Make up cell membranes
Lipids
• Lipids are usually formed through the dehydration synthesis of a glycerol molecule and 3 chains of fatty acids.
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Lipids
• Saturated is a term that refers to a lipid containing only single covalent bonds between carbon atoms in the fatty acid tails
• Unsaturated means that there are one or more double bonds between carbons in the tails of the lipid.
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3) Nucleic Acids
• The molecules of heredity!• Contain Hydrogen,
Oxygen, Nitrogen, Carbon and Phosphorus.
• Individual monomers are known as nucleotides.
• Nucleotides have 3 parts: a 5-carbon sugar, a phosphate group, and a nitrogenous base.
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Nucleic Acids
• There are two possible pentose sugars in a nucleic acid: Ribose and Deoxyribose.
• DNA has deoxyribose
• RNA has ribose
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4) Protein
• The R groups have varying properties: some are acidic, basic, polar, or nonpolar in nature.
• Proteins have a diverse
role in biology. – Some are for transport
(COPI, COPII, actin, myosin)
– Structure (muscle, bones)
– Regulation of cellular activities (cell cycle)
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Protein Organization
• 4 levels of organization– Primary = individual sequence of amino acids in a
protein.– Secondary = Hydrogen bonding causes folds and
twists in between AA (-helix, pleated sheets).
– Tertiary = 3-dimensional folding occurs within the chain.
– Quaternary = Multiple chains can fold on each other (Hemoglobin).