Chemistry of Life

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Chemistry of Life

• Unit 3 (Chapter 2)

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Atoms

• Smallest unit of matter that cannot be broken
  down by chemical means
• Made of
• Protons positive in nucleus
• Electrons negative in a cloud around nucleus
• Neutrons no charge in nucleus

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Atoms
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Element

• Pure substance made of only one kind of atom
• C, N, H, O most common in living organisms
• Periodic table LOTS of info

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Periodic Table
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Compound

• Substance made of the joined atoms of two or more
  different elements
• Example Sodium Chloride (NaCl)

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UNDERSTANDING CHECK

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Mixture

• Combination of 2 or more compounds that can be
  separated by physical means
• Trail mix
• Air

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Chemical Bonds

• Covalent Bonds when 2 or more atoms SHARE
  electrons to form a molecule
• Example H2O

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Chemical Bonds

• Ionic Bonds forms between ions of opposite
  charge
• Ion charged particle ( or ) from the loss or
  gain of electron(s)
• Example NaCl Na Cl-
• Animation

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Chemical Bonds
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Water Why so important?

• Changes temperature slowly
• Polar molecule
• Positive ears
• Negative chin
• Connects to other water molecules by hydrogen
  bonds - animation

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Water Why so important?

• Cohesion attraction between substances of the
  same kind
• Surface tension of water
• Adhesion attraction between different polar
  substances
• Paper towel cleaning up water

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UNDERSTANDING CHECK

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Why is water so special?

• 4 reasons that water is so special
• Which is denser ice or liquid water?
• So what happens to ice when you put it in liquid
  water?
• How can aquatic organisms survive in a frozen
  lake?

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Solution

• Mixture in which one or more substances is evenly
  distributed in another substance
• Water is the universal solvent
• BUT non-polar molecules do not dissolve well in
  water
• Example oil water

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Acids Bases

• Acids form H when dissolved in water
• Example stomach acid
• Bases lower concentration of H when dissolved
  in water
• Example TUMS (antacid)
• Many bases form OH- in water

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The pH scale

• Based on the concentration of H in a solution
• Each number represents a factor of 10 on the
  scale.

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UNDERSTANDING CHECK

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Chemistry of Cells

• Organic Compounds

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Macromolecules

• Macro large
• Cells make a variety of macromolecules from a
  small set of MONOMERS
• Like bricks to make buildings

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Carbohydrates

• Made of carbon, hydrogen, oxygen
• CHO 121
• Function Key source of energy

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Types of Carbohydrates

• Monosaccharides
• Glucose fructose
• Disaccharides
• Sucrose lactose
• Polysaccharides
• Starch glycogen
• Cellulose

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Lipids

• Characteristics
• Non-polar
• insoluble in water
• Types of lipids
• Fats
• Phospholipids part of cell membrane
• Steroids including cholesterol
• Waxes pigments

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Lipids - Fats

• Function store energy
• Structure 3 fatty acids attached to glycerol
• Saturated vs. Unsaturated
• solid liquid

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UNDERSTANDING CHECK

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Proteins

• Made of amino acids
• Essential vs. nonessential AA
• LOTS of different types/functions
• Enzymes
• Structural
• In your blood

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Proteins

• Function is determined by its SHAPE
• Conformation (3D shape) is determined by the
  sequence of amino acids

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Nucleic Acids

• Long chain of nucleotides
• RNA
• DNA

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ATP

• Adenosine Triphosphate
• Energy storing molecule

P
P
P
ADENOSINE
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Major Points

• Make half your grains whole.
• Vary your veggies.
• Focus on fruits.
• Get your calcium-rich foods.
• Go lean with protein.
• Physical activity.

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Energy

• Ability to move or change matter
• Can be converted between different forms light,
  heat, electrical, etc.
• Chemical reaction stores or releases energy by
  breaking or forming bonds
• Reactants ? products
• NaCl ? Na Cl-

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Energy in Chemical Reactions
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Enzymes

• Substances that increase the speed of a chemical
  reaction
• Most are proteins end in ase
• Lactase
• Lipase

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Activation energy

• The energy needed to start a chemical reaction
• Catalyst substances that reduce the activation
  energy of a reaction
• Enzymes are one kind of catalyst and control the
  rate of metabolic reactions in living cells

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Activation Energy
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UNDERSTANDING CHECK

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How do enzymes work?

• Substrate molecule that an enzyme binds to
• Active site part of the enzyme that binds to
  the substrate
• Sothe substrate binds to the active site of an
  enzyme
• Based on SHAPE (they are proteins)

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How do enzymes work?

• Lowering activation energy
• Pull 2 molecules together
• Push 2 parts of a molecule apart

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Factors in Enzyme Activity

• Anything that changes the shape of an enzyme
• Temperature
• pH
• Different cells contain different enzymes
  therefore have different functions.

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UNDERSTANDING CHECK