Bio 124 Exam #1 - Evolution, Cell Theory, Molecular Structure/Bonding, Carbon, Organic Molecules

The practice of observing & documenting findings; prominent until 1860

• 1. All living things come from cells
• 2. All cells come from pre-existing cells
• Coined in 1860

• First to identify cells within a cork using 30x magnification.
• 1640's

• 1. Identified other things that were composed of cells
• 2. Created a 300x microscope
• 1645

• He sterilized pondwater in two differently-shaped flasks;
• In 1860, this experiment refuted spontaneous generation - supporting the second part of Cell Theory

• Published entire cell theory in 1860.
• This meant all living things had a common ancestor.

Genetic change in a population over time.

• Darwin (with Alfred Wallace) introduced Natural Selection as a component of Evolution & common ancestry.
• Went on a 5 year naturalist voyage:
• - Observed armadillo evolution thru fossils
• - Explored volcanoes & habitats (finches)

Process of evolution - subset of a population possesses a genetic trait that makes them more likely to survive and have offspring.

He began using mathematical models to make predictions to compare with his observed biological data.

• 4.6 Billion years old
• 3.4 Billion years of life

• The science of organizing living things.
• Created by Carl Linnaeus

• Swedish physician/botanist:
• - Created taxonomy
• - Used morphology for classification
• - Created 2 Kingdom System
• - Created 7 Level Hierarchy of organization
• - Created scientific naming system

Classification of living things by physical features. (used by Carl Linneaus)

• - Plants
• - Animals
• (Created by Carl Linnaeus)

• 1. Kingdom
• 2. Phylum
• 3. Class
• 4. Order
• 5. Family
• 6. Genus
• 7. Species

"King Phillip Came Over For Good Spaghetti"

(Carl Linnaeus)

Genus + Species

(Carl Linnaeus)

• Used Morphology to explore RNA sequencing.
• Created the 6-kingdom system:
• (Prokaryotes/No Nucleus)
• 1. Bacteria
• 2. Archae
• (Eukaryotes/With Nucleus)
• 3. Fungus
• 4. Protists
• 5. Plants
• 6. Animals

An organism with no nucleus.

An organism with a nucleus.

Used RNA sequencing to classify organisms in the 1970's.

• Species 1 AAUUUUGGGCGCGC (original)
• Species 2 AAUUAAGGGGGCGC (3 differences)
• Species 3 AUUUUAGGGGGGGG (5 differences)

Timeline for change: 1...2.....3

3-Kingdom System - "domain is broader than kingdom"

• 1. Bacteria
• 2. Archae
• 3. Eukarya

Protists - Fungi - Plants - Animals

Non-motile.

(total mag at low)(FOVd at low)=(total mag at med)(FOVd at med) 

Solve for last value.

A=(Pi)r^2.

• Anything that takes up space and has mass.
• Matter is made up of 92 naturally occurring elements.

The smallest particle that still retains the quality of an element (e.g. 1 atom of oxygen)

• Atoms are made of 3 subatomic particles:
• 1. Protons
• 2. Neutrons
• 3. Electrons

• - Positive charge (+1)
• - Has mass (1 amu)
• - Located in atomic nucleus

• - No charge
• - Has mass (1 amu)
• - Located in atomic nucleus

• - Has negative charge (-1)
• - Does not have mass
• - Orbits atomic nucleus

# protons = # neutrons = # electrons

• 12: Atomic Mass (# protons + # neutrons)
• 6: Atomic Number (# protons)
• C: Symbol

• 1. First orbital/shell can only hold 2 electrons.
• 2. 2nd & 3rd orbitals/shells can hold up to 8 electrons.
• 3. All 4 poles of the orbital must be filled with an electron before pairing.

Electrons in the outer shell.

When 2 or more atoms bond together.

• 1. Covalent
• 2. Ionic
• 3. Hydrogen

• - Strongest chemical bond
• - Valence electrons are shared

Non-polar covalent bond: Valence electrons are shared equally

Polar covalent bond: Valence electrons are shared unequally, causing a charge difference between poles.

• 1. Hydrogen: Has no neutron. p/=/n. (+1, 1e-)
• 2. Ion: Protons /=/ electrons.
• - + charged Ion (lost electron) (cation)
• - - charged Ion (gained electron) (anion)
• 3. Isotope: Protons /=/ neutrons.

When an atom/molecule has more protons than neutrons - gives off neutrons and high energy waves.

• - Medium strength
• - Ionic bonds form by gaining or losing an electron.
• Cation: When an atom loses an electron. (pos)
• Anion: When an atom gains an electron. (neg)

Cations are attracted to Anions due to the opposite charge.

• - A weak attraction between a slightly positive hydrogen and a negative atom/molecule.
• - Weakest bond
• e.g.: The bond between H2O molecules; bond bases in a DNA molecule.

• Theory that states under the conditions of primitive earth, small inorganic molecules came together to form larger, more complex organic molecules (proteins, lipids, carbs) - was the first step in the development of life.
• This occurred in water.

• 1. H2O is less dense as a solid (ice) than a liquid: Ice floats and prevents solid build-up of ice, allowing chemical rxns to occur in liquid H2O.
• 2. H2O is a universal solvent: More things dissolve in H2O than anything else. (partly due to positive and negative charges of H2O molecules)
• 3. H2O is a heat sink: It creates a stable, thermal environment to preserve newly created molecules. The # of hydrogen molecules in H2O takes much more force to break with temperature.
• 4. H2O can act as an acid or a base: Water can break down into Hydrogen ions or Hydroxy ions (H+ & OH-); this increases the types of chemical reactions that can occur.

• Carbon, Hydrogen, Oxygen and Nitrogen
• Proteins, Lipids, Carbohydrates, Nucleic Acids

• Created the spark discharge apparatus to mimic the conditions of primitive earth and replicate chemical evolution.
• After implementing electrodes to mimic lightning, resulted in amino acid, fatty acid tails, monosaccharides - building blocks of organic molecules. (except nucleic acids)

Used computer modeling to ask questions about chemical evolution - results were very similar to those of the spark discharge apparatus. (1980's)

Solvent (liquid) + solute (solid).

• 6.02 x 10^23.
• Represents number of molecules, atoms, etc per mole.

Measure out the molecular weight of a molecule (in grams) and dissolve it with an H2O solvent up to 1L.

• Example: NaCl.
• - Na atomic mass: 22g.
• - Cl atomic mass: 34.
• 22g + 34g = 56g NaCl.
• Put this in a container, and add water up to 1L. This is 1 mole of NaCl solution.