Biology 101

Atoms, Molecules, and Life

Here lies my least favorite part of biology so far.......wait for it....

ATOMS AND MOLECULES  AND LIFE

Oh my. 

Anyway, so lets begin this shit before I fall asleep.

My teacher gave us these objectives at the beginning of her lecture.

1. Describe the relationship between elements, atoms, and molecules.

2. Describe structures of atoms and characteristics of the 3 types of chemical bonds.

3. Define isotopes and their impact on the characteristics of life.

4. Describe special properties of water.

5. Describes properties of acids and bases.

By the way, if any of you guys care I am listening to Skinny Puppy by Protest. I don't know I was retyping my notes while listening to music so I got distracted oh well.

Did you know atoms are composed of subatomic particles? No? Cool. WRITE IT DOWN.

Compounds= substances that contain two or more elements in a fixed ratio. 

Isotopes= variants of an element that while all having the same number of protons, have differing numbers of neutrons.

The nucleus of a radioactive isotope (unstable isotopes) decays spontaneously giving of particles and energy. 

Uncontrolled exposure to radioactive isotopes can harm living organisms by damaging DNA. 

Naturally occurring radon gas may cause lung cancer. (Random fact my teacher gave me)

There are three types of chemical bonds. Ionic, covalent, and hydrogen.

New song: There's No Sympathy For The Dead-Escape the Fate

In case you haven't noticed I am into rock and screamo music if you care.

Ionic bonds- complete transfer of valence electrons between atoms.

Stronger than a hydrogen bond

Weaker than a covalent bond

One or more electrons are removed and attached to another atom.

Covalent bonds- forms when two atoms share one or more pairs of outer shell electrons.

Strongest of the bonds

Holds atoms together in a molecule

Hydrogen bonds- weak bond between two molecules resulting from an electrostatic attraction.

Weakest of the bonds

Strong enough to hold together water and DNA

Water=compound with -e covalent bond, unequally shared

A water molecule (H2O) is made up of three atoms

Water is polar

Cells are made up of 70-95% water

At sea level, water boils at 100 degrees celsius

-the boiling temperature of water decreases at higher elevations.

Water

Cohesion

Adhesion

High specific heat

High heat of vaporization

Water is less dense than a solid

Homeostasis

Cohesion- attraction between particles of the same substance (why water is attracted to itself)

-results in surface tension (a measure of the strength of water's surface)

Adhesion- attraction between two different substances

-capillary action (water molecules "tow" each other along when in thin glass tube)

High Specific Heat- amount of heat needed to raise or lower 1g of a substance at 1 degree celsius.

-water resists temperature change for both heating and cooling

-water can absorb or release large amounts of heat energy with little change in actual temperature

High Heat of Vaporization-amount of energy to convert 1g or a substance from a liquid to a gas.

-in order for water to evaporate, hydrogen bonds must be broken

-as water evaporates, it removes a lot heat with it

-water vapors form a kind of global "blanket" which helps to keep the Earth warm.

-heat radiated from the sun warmed surface of the Earth is absorbed and held by vapor.

Water is Less Dense Than a Solid-ice is less dense as a solid than as a liquid (ice floats).

-liquid water has hydrogen bonds that are constantly being broken and reformed

Homeostasis- ability to maintain a steady state despite changing conditions.

-water is important to the process because:

Makes good insulator

Resists temperature change

Universal salvant

Coolant

Ice protects against temperature extreme (insulates frozen lakes)

Solutions and Suspensions

Water is usually part of a mixture

Evenly distributed

Solute- substance that is being dissolved

Solvent- substance in which the solute dissolves

The plt scale indicates the concentration of the H+ic

Ranges from 0-14

Plt 0 up to 7 is acid (many free of H+)

Plt of 7 is neutral

Buffers

Weak acids or bases that react with strong acids to prevent sharp, sudden changes in pH (neutralization)

Produced naturally by body to maintain homeostasis

Accept H+ ions when they are in excess

Review:

Bonds

-Ionic

Atom donates valence electrons to another atom

-Covalent

Atoms share valence electrons

Strong bonds

May be single, double, or triple bonds

Hold carbon molecules together

-Hydrogen

Molecules with atoms of unequal electronegativity

pH

-concentration of hydrogen ions

PS I got tired of retyping so I just copy and pasted my notes from my study guide. Sorry if it is boring but I don't know how to make this part interesting. The reason I kept saying what song I was listening to was to give you kind of a break from all that crap. By the way, I have been watching this show called iZombie, I thought it was going to suck but it is actually pretty captivating, at least for me anyway. Anyway, next part will be up soon (hopefully).

Should I put the labs we do here to? Answer in comments.