CHEM 120 Week 8 Final Exam Review (Version 1), Introduction to General, Organic & Biological Chemistry, Chamberlain College of Nursing

CHEM120: Final Review:


1. Question: Know what is the atomic number, atomic mass, protons, neutrons &
electrons

Atomic number – is the number of protons in the nucleus of an atom of any
element
Atomic mass – is expressed in amu; is the wighted average
Protons – are positively charged particles in the nucleus
Neutron – are neutral, have no electrical charge
Electrons – are negatively charged particles in the nucleus
Atomic number = number of protons
Atomic number – (minus) atomic mass = neutrons

2. Question: Describe the shapes of molecules H2S, CBr4, & PCl3

H2S – bent
 Number of bonded atoms: 2
 Number of lone pairs: 2
 Number of electron sets: 4
CBr4 – tetrahedral
 Number of bonded atoms: 4
 Number of lone pairs: 0
 Number of electron sets: 4
PCl3 – pyramidal
 Number of bonded atoms: 3
 Number of lone pairs: 1
 Number of electron sets: 4
3. Question: Calculating types of bonding (ionic, covalent, nonpolar covalent)

Subtract the smaller EN value from the larger EN value
 0 – 0.4 = nonpolar covalent
 > (greater than) 0.4 – 1.7 = polar covalent
 > (greater than) 1.7 = ionic bond
Ionic bonds – is a bond that forms when electrons is being transferred from one form to
another form, which results in positive & negative ions
Covalent bond – a bond formed when atoms share electrons
Nonpolar covalent bonds – when the EN is very similar between 2 atoms
Polar covalent – when the EN is different between 2 atoms

4. Question: Non – polar covalent bonds & polar covalent bonds & electron sharing

Bonding electron pair – the shared pair of electrons in covalent bonds
Nonbonding pairs or lone pairs – the electrons that are not shared as part of the
covalent bond

, Nonpolar covalent bonds – when the EN is very similar between 2 atoms
Polar covalent – when the EN is different between 2 atoms

5. Question: Know the structure & makeup of DNA & RNA, know what DNA
replication, transcription & translation are & ribosomes role in protein synthesis.

Deoxyribonucleic acid (DNA) – provides a mechanism for heredity & serves as
the blueprint for all the proteins of an organism
 The DNA helix is held together by hydrogen bonds between the
nucleotides
 Adenine (A) binds with Thymine (T) in DNA
 Guanine (G) binds with Cytosine (C) in DNA & RNA
 DNA complimentary base pairs: A – T; C – G
 DNA is made up of genes that code for specific proteins
Ribonucleic acid (RNA) – carries information needed to the protein synthesis
 Adenine (A) binds with Uracil (U) in RNA
 Guanine (G) binds with Cytosine (C) in DNA & RNA
 RNA complimentary base pairs: A – U; C – G
DNA & RNA are polymers of repeating units of nucleotides
DNA Replication – is copying or duplication of DNA molecules
Transcription – the transfer of the DNA gene information to RNA which is
transported out of the nucleus
 A segment of DNA called the template str& transfers its information
to a special RNA molecule called messenger RNA
 The base sequence of DNA specifies the base sequence of mRNA
 In eukaryotes the mRNA is transported out of the nucleus to the
ribosome
Translation – the translation of the mRNA sequence into a specific protein
 Decoding of the mRNA results in protein synthesis which occurs in the
ribosome in the cytoplasm of the cell

6. Question: Know what a protein is, its makeup & what is primary, tertiary
(globular), & quaternary structure. Also the types of bonds that holds the
structure together.

Proteins – serve as the structural materials & enzymes of animals
 Muscle tissue, skin & hair are mostly proteins
 Silk, wool, nails, claws, feathers, horns, & hooves are proteins
 Proteins are polymers with the monomer units are about 20 different
amino acids
 The amino acids differ in their side chains
The structure of proteins have four organizational levels:
Primary Structure – is simply the order of its amino acids; held together by the chain of
amino acids