Summary Biol 120 Final Exam Study Guide.

BIOL 102- Dr. Terry Spohn
Chapter one pt 1

Chemistry - the study of matter and the energy used to change it
Matter- anything that has mass and volume
-Composed of elements
Elements- cannot be simplified
periodic table- lists all known elements
Atoms- smallest functional unit of elements
- Nucleus (central core)
o Protons
▪ Have a positive charge
▪ Have mass
o Neutrons
▪ No charge
▪ Have mass
- Shells (surrounding nucleus)
o Electrons
▪ Negative charge
▪ No discernable mass
- Colossians 1:17 explains why atoms are able to stay together while repelling
themselves
- Atomic symbol- one or 2 letters
- Atomic number- number of protons (and electrons before a reaction)
- Atomic mass- roughly equal to protons + neutrons
- In an electrically neutral atom, number of protons = number of electrons
o First shell- 2 electrons
o Second shell- eight electrons
o Third shell- eighteen electrons
o To be electronically stable, there has to be 18 on the outer shell or 8
- Isotopes have a different number of neutrons
o Same atomic number (same number of protons)
o Different atomic mass (different number of neutrons)
o Unstable isotopes are called radioisotopes
o Radioisotopes give off
▪ Energy (in the form of radiation)
▪ Particles
- Some radio isotopes have scientific and medical uses
o Carbon 14 used for dating fossils
o Diagnostic imaging
o Cancer treatment
o Power supply for implants such as cardiac pacemakers

, BIOL 102 Notes PT 3
Dr. Terry Spohn-Liberty University


The importance of Hydrogen Ions:
• Acids
o Donate H ions (protons)
o Increase H ion concentration in solutions
• Bases
o Accept H ions
o Lower H ion concentration in solution
• pH scale
o a measure of hydrogen ion concentration
o acids have a pH less than 7
o bases have a pH greater than 7
Buffers
• minimize pH change
• help maintain stable pH in body fluids
• aroi aid ad iaroate at as oe of the ody’s ost iportat uffer pairs
• weak acids stay in water

Organic Molecules of Living Organisms
• carbon- the building block if living things
o comprises 18% of the body by weight
• can form 4 covalent bonds
• can form single or double bonds
• can build micro or macromolecules

Macromolecules are synthesized and broken down in the cell
• dehydration synthesis
o removes equivalent of a water molecule to link molecular units
o requires energy
o builds macromolecules from smaller subunits
• Hydrolysis
o Adds the equivalent of a water molecule to break apart macromolecules
o Releases energy
• Dehydration synthesis is the reverse of hydrolysis

Carbohydrates: used for energy and structural support
• Monosaccharides: simple sugars
o Glucose
o Fructose
o Galactose

,o Ribose
o Deoxyribose

, BIOL 102- Dr. Spohn Liberty University
Chapter 1 pt 2

• Energy- the capacity to do work
• Potential energy- stored energy
• Kinetic energy- energy in motion, energy doing work
• Electrons have potential energy
o Each shell corresponds to a specific level of potential energy
o Shells further from the nucleus contain electrons with more potential energy
• Atoms are more stable when the outer shell is full
• Atoms will interact with other shells to fill outer shell

• Chemical bonds link atoms to form molecules
o Chemical bonds- attractive forces holding atoms together
o Kinds of chemical bonds
▪ Covalent bonds
▪ Ionic bonds
▪ Hydrogen bonds
o Strength of a bond determined by amount of energy it takes to break it

• Molecule- 2 or more atoms chemically bonded together
• Compound- 2 or more different atoms chemically bonded together
• Covalent bonds form when atoms share electrons
o Very strong bonds
o H2, O2, H2O
• Nonpolar covalent bonds- electrons shared equally
• Polar covalent bonds- electrons not shared equally

• Ionic bonds
o Ion- an electrically charged atom or molecule
o Positively charged ion forms if an electron is lost
o Negatively charged ion forms if an electron is gained
o Ionic bond- attractive force between oppositely charged ions

• Hydrogen bonds
o Form between polar molecules
o Polar molecules:
▪ Contain polar covalent bonds in which there is unequal sharing of
electrons
▪ Electrically neutral overall, but uneven charge distribution
o Hydrogen bonds
▪ Weak attraction between oppositely charged regions of polar molecules
▪ Ex. Weak forces between water molecules