Unit 2 Physiology Lecture: A Review of  Basic Chemistry

 

Lecture

Questions: Unit 2 – Chemistry - Use in 2009

Lab: "Organic Chemistry"- Use in 2009

There will be one more lab. Stay tuned!

 

Due to the room changes, the following assignments will NOT be used in 2009

A. Questions: Unit 2 - Chemistry – Not in 2009

B. Question Unit 2 – Chemistry  - Not in 2009
Lab: pH – Not in 2009
Lab: "Scientific Experiment"  Not in 2009

 

 

California Standard   

5. a. Students know the general structures and functions of DNA, RNA, and protein.

5. b. Students know how to apply base-pairing rules to explain precise copying of DNA during

 

Part 1. Basic Chemistry/Inorganic Compounds

I. Matter: Anything which has mass and occupies space.
II. Atoms: Building blocks of all matter.
1. Composed of 3 particles

a. Protons +, located in nucleus
b. Neutrons o, located in nucleus
c. Electrons -, located in electron cloud, energy levels, electron shells.

2. Levels represent probable distances of electrons to nucleus.

a. electrons are assorted in energy levels according ot our "model" of the atom: 1st, 2nd, 3rd, 4th, etc.
b. electrons fill shells (quantum levels) - 2, 8, 8, 18, etc.

3. Free atoms in nature are neutral atoms which have the same number or electrons and protons.


III. Elements: Substances composed of only one type of atom. All elements of same kind have same atomic number.
1. Periodic table of the elements lists the known elements.

a. Atomic number: number of protons+
b. Number of protons determines what the element is regardless of the number of neutrons and electrons.
c. Atomic Mass: number of protons + and neutrons + given in atomic mass units (AMU).

3. Know examples: oxygen, carbon, hydrogen, helium, iron, potassium.
4. Symbols: Letters on the periodic table which represent the elements: H, O, Fe, K, Cl, Pb, etc.
5. Isotopes: Two or more atoms of the same type which differ in the number of neutrons.
6. Draw examples of atoms with levels.
7. Mole: 6.02 x 1024 atoms. Mass of element equal to its atomic mass.


IV. Molecules:

1. 92 different elements exist naturally; however, there are thousands of different substances.
2. Two or more atoms combined chemically are called molecules.
3. Chemical bonds: forces which hold atoms together.

a. Covalent bonds: sharing of electrons.
b. One pair of electron in a bond. There are also double and triple bonds.
c. Ionic bonds: Electrons are transferred, then appositely charged atoms (ions) are held together by attraction of opposite charges.
c. Cations +
d. Anions -

4. Follow octet rule or duet rule in obtaining outer electron configuration of Nobel Gases.
5. Formulas: Chemical formulas are the combined symbols which represent molecules. H2O, CO2, C6H12O6

a. subscripts determine number of atoms in formula. Coefficients in front of formulas determine number of molecules. 2H2O.

6. Diatomic molecules: Some elements such as hydrogen, oxygen, chlorine exits as molecules of 2 atoms: H2, O2, Cl2


V. Compounds (compound molecules)


1. Molecules composed of 2 or more different atoms (elements).
2. Ionic bonds produce ionic compounds (NaCl) - metal and non-metal

a. Cation + is electron donor. Anion - is electron acceptor.

3. Covalent bonds produce covalent or molecular compounds - 2 nonmetals.

a. Covalent bonds form polar or non polar compound. In polar bonds the electron pairs are pulled closer to one of the atoms in the molecule give the ends relative "charges".
b. In water these polar bonds are called hydrogen bonds and they form relatively strong intermolecular forces. This gives water surface tension.
c. Polar substances dissolve in water. Non polar substances do not.

VI. Chemical change:

a. Chemical reactions: rearrangement of atoms of reactants to produce new substances in products.
b. Chemical equations represent chemical reactions. Must be balance to conform with Law of Conservation of Mass. Matter can not be created or destroyed. It can be changed from one form to another. When it is matter is conserved. Elements in reactants must equal elements in products. Use coefficients to balance equations. H2 + O2 ---- H2O.
c. Types of chemical reactions: Decomposition, synthesis, exchange,

VII. Solutions: Mixtures composed of two or more substances - solvent and solute.


1. Water is an excellent solvent.  70% of organisms are composed of water.
2. Solvent: material in greater amount
3. Solute: material in lesser quantity.
4. Homogeneous solutions are the same throughout.
5. Polar covalent compounds dissolve in water: sugar and water.
6. Ionic compounds dissociate (come apart).


VIII. Acids and Bases


1. H+ hydrogen ion
2. OH- hydroxide ion.
3. HOH = H2O
4. pH = amount of acidity or alkalinity (base). pH = 0 - 14
5. Scale is based on number of H+ ions in solution = moles/Liter.
6. pH 7 - one ten millionth of a mole 1/10,000,000 M/L or 10-7
7. .001 M/L =.10-4 = pH 4
8. .000000009 M/L = 10-9 = pH 9.
9. pH 7 = neutral, 0 - 6.999 = acid. 7.001 - 14 = base.
10. [H+] [OH-]  acid
11. [OH-]   [H+] base
12. [H+] = [OH-] neutral or water, pH 7
13. pH is an important biological factor: enzymes operate under strict pH conditions. Stomach acid is 1 or 2. Small intestines is about 8.
14. Buffers: are compounds that stabilize the pH of a solution by removing or replacing hydrogen ions. Buffer systems involve a weak acid and its related salt which acts like a weak base.


IX. States of Matter.


1. Solids: definite mass, volume, and shape. Incompressible.
2. Liquids: Definite mass, volume, but no definite shape. Incompressible.
3. Gases: Definite mass, no definite volume, no definite shape. Compressible.


X. Energy


1. Kinetic energy - energy of motion
2. Potential energy - stored energy

Part 2. Organic Compounds

I. Carbon Compounds
1. Previously called organic compounds because only produced by living things.
2. Now are produced in laboratory.
3. All contain the element carbon C.
4. Study of these compounds is called organic chemistry.
5. Carbon has 4 electrons in outer level. According to octet rule needs 4 more electrons and can form 4 bonds.
6. Carbon can combine with other elements or themselves to form molecules of 10,000 or more atoms.
II. Structural formulas
1. Molecular formulas show number and kinds of atoms: CO2, H20, CH4
2. Organic compounds are complex.  The arrangement of atoms in space must also be known. E.g., Methane and Octane
3. Isomers are variations of the structural formula but not the molecular formula.  See octane.
4. Isomers have different chemical and physical properties.
III. Carbohydrates: Figures
1. Composed of C, H, and O: ration of H to O is always 2:1
2. Building blocks of carbohydrates are monosaccharides - single sugars.
3. Glucose is important carbohydrate produced by plants - C6H12O6
4. Carbohydrates are an important energy source.
5. Monosaccharides combine to form more complex sugars: disaccharides.

  • table sugar - sucrose, glucose + fructose
  • maltose, glucose + glucose
  • lactose, glucose + galactose

6. Combinations of larger molecules are called polysaccharides.
7. Starches are the most complex carbohydrates.
8. Starches are composed of 100's of monosaccharides. Plants store energy in this form: Potatoes, rice, grain.
9. Cellulose is carb. use for plant structure.
10. glycogen is and animal carbohydrate. Used as ready reserve of glucose (branching chain of glucose). Produced in liver and muscle tissue. Also lubricant in vagina.
IV. Lipids Figures
1. Class of organic compounds which includes fats, waxes, and oils.
2. Composed of C, H, and O. Ration of H to O is greater than 2:1.
3. Fats are more complex than carbohydrates
4. Used for lubrication, protection, energy storage.
5. Building blocks of Lipids are fatty acids and glycerol. See figures.
6. Many different kinds of fatty acid molecules: all have one part in common: carboxyl group, COOH. See figures.
7. Prostiglandins are short-chain fatty acids. Control local cell activities. 1. released by injured cells and produces pain and inflammation. 2. triggers labor contractions in uterus.
8. Steroids are lipids. Cholesterol, testosterone, progesterone, estrogen.
V. Proteins: Figures
1. Contain C, H, and O, but also N (NH2 is amino group)
2. Much larger and more complex than lipid and carb.
3. Not normally used as energy sources. Rather building blocks of living material and enzymes.
4. Building blocks of proteins are amino acids. See figures.
5. 20 different amino acids.
6. Each contains central C, carboxyl group, H atom, and amino group.
7. Amino acids are held together by peptide bonds. 2 amino acids are called dipeptides.
8. Polypeptides combine to form larger molecules: protein.
9. Though only 20 amino acids, there are thousands of proteins.
10. Proteins differ in number, kinds, and sequence of amino acids. See primary, secondary, tertiary, and quaternary structure.
11. E.g., hemoglobin, hair, nails

12. Enzymes follow lock and key hypothesis, enzyme, substrate, active sites, reduce activation energy. Are reusable, unchanged, not used up.
13. Dehydration synthesis (condensation) and Hydrolysis use enzymes to form or break bonds in organic compounds.
V. Nucleic Acids.
1. Most complex of all biological compounds.
2. Consist of hundreds of thousands of atoms.
3. 2 important nucleic acids: deoxyribonucleic acid (DNA). Ribonucleic acid (RNA).
4. Control heredity. DNA contains "genetic code". RNA works with DNA in carrying out instructions of the DNA code.
5. Not an energy source.