Chemistry to life

Unit I Part II: From Chemistry to Life

A. Atomic Theory

Atoms are building blocks of elements

1. Subatomic Particles

Particle Symbol Charge Relative Mass Electron e- 1- 0

Proton p+ + 1

Neutron n 0 1

a. Atomic Number

• Counts the number of protons in an atom

b. Periodic Table

Represents physical and chemical behavior

of elements

Arranges elements by increasing atomic

number

Repeats similar properties in columns known

as chemical families or groups

Atomic Number on the Periodic Table

11

Na

Atomic Number

Symbol

All atoms of an element have the same number of protons

11 protons

c. Number of ElectronsAn atom is neutral The net charge is zeroNumber of protons = Number of electronsAtomic number = Number of electrons

d. Mass Number

Counts the number of protons and neutrons in an atom

e. Isotopes

Atoms with the same number of protons, but

different numbers of neutrons.

Atoms of the same element (same atomic

number) with different mass numbers

Isotopes of chlorine

35Cl 37Cl17 17

chlorine - 35 chlorine - 37

f. Radioactive (decay) Isotopes

• They change their chemical identity as they shed particles and emit high-energy radiation.

• They decay until they become lighter and stable.

• This rate they decay at is the half-life

• Electrically charged atoms made by gaining or losing electrons

h. Molecules

g. Ions

• Combination of 2 or more atoms O2

i. Compound

• A molecule composed of atoms of 2 or more different elements H2O, Co2

• Atoms share electrons

k. Polar Covalent Bonds

j. Covalent Bond

l. Ionic Bonds

• (Water) 1 attracts the electrons more than the other (Oxygen)

• When electron is transferred from one atom to another

• Creates ionic compounds (salts)

• Homogeneous mixtures (don’t chemically combine)• Usually associated with liquids but also happens in the

air

m. Solutions

n. Water Molecules

• Able to support life because of it’s chemical properties

• Strong cohesion

• High specific heat

• Expands when freezing

• Bond well with polar molecules

• Determine acidity, a small amount of water molecules separate forming a hydrogen (H+) ion and a hydroxide (OH-) ion.

• Pure water contains equal numbers of each making it neutral (10-7)

• Greater H+ is acidic and greater OH- is basic • pH less than 7 = acidic• pH greater than 7 = basic

1) Hydrogen Ions

1. An organic compound is one that has carbon as the principal element. Carbon’s ability to build big molecules results in millions of different organic compounds.

2. An inorganic element is any compound that is not an organic compound.a. Hydrocarbons- consist of only hydrogen and carbon (crude oil and petroleum)

1) Methane = simplest hydrocarbon and is the key component of natural gas.

2) smallest = gas, Larger = liquids, largest = solids

B. Matter

C. Macromolecules 1. Proteins- some provide structure, produce tissues,

store energy, defend organisms, and some transport substances, and also serve as enzymes.

2. Nucleic Acids- DNA and RNA- carry hereditary information.

3. Carbohydrates- sugars (monosaccharide) provides energy that fuels plant and animal cells

4. Lipids- do not dissolve in water. a. Fats and oils- store energy and release it when burnedb. Phospholipids- one side attracted to water other side is not

so forms cell membranesc. Waxes- structural roles (bee’s wax)d. Steroids- produce hormones

D. Synthetic Polymers 1. Human made polymers are plastics

They resist chemical breakdown Products make our lives easier because of this but also have

long term effects on the environment.

EUKARYOTIC CELL

E. Energy Fundamentals

1.Energy- intangible, can change the position, physical composition, or temperature of matter.

2.Types: Potential, Kinetic

a. Chemical energy – potential energy held in the bonds between atoms.

3. Laws of thermodynamics1. First law- energy can change form but not be created or

destroyed

2. Second law- the nature of energy will change from a more-ordered state to a less-ordered state if no force intervenes.

4. Light Energy

1. Sun is primary energy source for all life

2. Autotrophs are primary producers

a. Photosynthesis produces food for plants and animals

b. Cellular respiration occurs because organisms use the chemical energy created by photosynthesis.

5. Geothermal Energy1. Powered by radiation from radioisotopes deep inside the planet.

(drives the plates to move, volcanoes, warms groundwater and causes geysers)

2. Hydrothermal vents deep in the oceans produce enourmous amounts of heat energy.

Chemosynthesis occurs here – process where inorganic carbon is turned into organic compounds