Bio Test 1

Basic material that cannot be broken down by a chemical reaction.

Two or more elements in a fixed ratio.

• O- Oxygen
• C- Carbon
• H-Hydrogen
• N- Nitrogen

Smallest unit of matter that still retains the properties of an element.

Neutrons - nucleas isotopes

Protons- nucleas type of element

• Electrons- shells/orbitals
• bond/react/energy

Ideal atom would have equal number of protons, neutrons, and electrons

Isotope is the same element with a different number of neutrons.

• An ion has an unequal number of e- and protons.
• - Cation - more protons + charge
• - Anion - more electrons - charge

Valence shells. First shell contains two electrons, all the rest need 8 per shell. if the shell is full it won't react, if not full it will react.

2 atoms sharing pairs of electrons.

Non-Polar - equal sharing, no charge

Polar - Unequal sharing due to electronegativity (attraction for electrons). Charge is partial pos or partial neg.

Two atoms Transfer electrons. Both atoms have charges, are elctronegative, always forms compunds.

A hydrogen atom bonds with a polar molecule. Very weak bonds, but many together is strong. Bonds with O, N,

Weak chemical bonds. Assymetrical distribution of electrons such as dispersion forces. Dipole-dipole bondings is also included.

Valence electrons, change shape...calter function.

WATER

POlar molecule with polar covalent bonds. Oxygen has a partial negative charge, while the hydrogen has a partial positive charge. Oxygen is stronger, more electronegative, so the H electrons spend more time around oxygen giving it a more negative charge.

• 1. Cohesion
• 2. Moderation of temperature
• 3. Expansion upon freezing. (water is less dense as solid)
• 4. Universal solvent of life.

• Specific Heat is amount of heat needed to raise or lower 1g of substance 1 degree celsius. Water is unusually high.
• Ex. Boil pan of water. Pan is extremely hot (low specific heat) when water is lukewarm (high specific heat).

Absorbs heat from air that is warm, releasing already stored heat to the cooler air.

Evaporative cooling occurs because the hottest particles turn to gas and escape surface, leaving the coolest particles behind.This stabilizes temperature.

Heat that must be absorbed for 1g of substance to turn to gas.

Solute: Dissolved by solvent

Solvent: the dissolving agent

Example is water surrounding a Na atom. This breaks ionic bonds by surroung agent. Molecules must be polar.

An acid is a subtance that will donate or increase hydronium or (H+) to a solution.

A base is a substance that reduce the amount of H+ hydronium ions by adding OH-.

Used to determine how acidic or basic a solution is. Based on a logarithum from pure water. Less than 7 is acidic more than 7 is basic. Neutral is 6-8. Each level is 10x stronger.

A buffer is a solution, usually weak acid or base, that will stabilize changes in a pH. It does this by absorbing or releasing hydronium (H+) ions.

Carbon can form single, double, or triple bonds. This varies length of carbon skeleton (linear or rings)(branched or unbranched).

Consist only of hydrogen and carbon. responsible as fats, oils

Release alot of energy

Compounds with same molecular formula but different structures and different properties. Bigger the structure, greater number of isomers.

Different bonding pattern

• Same bond arrangement, but different spatial arrangements.
• Cis Trans

• Cis- same side
• Trans- Opposite

Mirror images of each other. (like a left and right hand).

Adenosine Triphosphate.

• Primary energy source for cell.
• Strong potential to react with water.