Study Guide: Characteristics of Life and Introduction to Biomolecules
Study the following terms:
Carbohydrate
Lipid
Vitamin
Protein
Nucleic acid
DNA
RNA
Monomer
Polymer
Dehydration
synthesis
hydrolysis
Amino acid
Transcription
Translation
Polar
Nonpolar
Electronegativity
Polar bond
An organic compound build only of carbon, hydrogen, and oxygen, usually in a 1:2:1 ratio (ie.
hydrates of carbon = carbon plus water); function in energy storage, structure, and signaling
Group of biomolecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E,
and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others. The main biological
functions of lipids include storing energy, signaling, and structural components of cell membranes
An essential low molecular weight organic compound required in trace amounts for normal growth
and metabolic processes. They usually serve as components of coenzyme systems.
A molecule composed of polymers of amino acids joined together by peptide bonds. Proteins
perform a vast array of functions within living organisms, including catalyzing metabolic reactions,
replicating DNA, responding to stimuli, and transporting molecules from one location to another.
Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the
nucleotide sequence of their genes, and which usually results in folding of the protein into a specific
three-dimensional structure that determines its activity.
Includes complex compounds consisting of linear chains of nucleotides each of which is composed of
a phosphate, a 5-carbon sugar, and nitrogenous base, and involved in the preservation, replication,
and expression of hereditary information in every living cell. Nucleic acids also play important roles
in cellular energy transfer and signaling
Deoxyribonucleic acid; a polymer composed of nucleotides (the monomer)
Ribonucleic acid
Single unit
Something made of many units
a chemical reaction that involves the loss of a water molecule from the reacting molecules; often
used in the polymerization of macromolecules
a chemical reaction that involves the addition of a water molecule to the reacting molecule resulting
in the cleavage of a bong; often used in the depolymerization of macromolecules
biologically important organic compounds made from amine (-NH2) and carboxylic acid (-COOH)
functional groups, along with a side-chain specific to each amino acid. The key elements of an amino
acid are carbon, hydrogen, oxygen, and nitrogen, though other elements are found in the side-chains
of certain amino acids. These are the monomers used to build proteins
the first step of gene expression, in which a particular segment of DNA is copied into RNA by the
enzyme, RNA polymerase.
In molecular biology and genetics, translation is the process in which cellular ribosomes create
proteins. It is part of the process of gene expression. In translation, messenger RNA (mRNA)
produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or
polypeptide, that will later fold into an active protein.
In chemistry, polarity refers to a separation of electric charge across different parts of a molecule
A molecule or a part of a molecule is nonpolar when there is an equal sharing of electrons between
atoms resulting in NO difference in charge across different parts of the molecule
a chemical property that describes the tendency of an atom or a functional group to attract electrons
(or electron density) towards itself. The higher the associated electronegativity number, the more an
element or compound attracts electrons towards it.
In chemistry, a polar bond is a type of covalent bond between two atoms in which electrons are
shared unequally. Because of this, one end of the bond has a fractional negative charge and the
other a positive charge.
 Non-polar bonds occur when the difference in electronegativity between the two atoms is
less than 0.4
 Polar bonds occur when the difference in electronegativity between the two atoms is
between 0.4 and 2.0

Detergents /
surfactants
Homeostasis
metabolism
Covalent bond
Hydrogen
bond
Ionic bonds occur when the difference in electronegativity between the two atoms is
greater than 2.0
like soaps, these chemicals work because they are amphiphilic: partly hydrophilic (polar) and partly
hydrophobic (non-polar). Their dual nature facilitates the mixture of hydrophobic compounds (like
oil and grease) with water.
the property of a system that regulates its internal environment and tends to maintain a stable,
relatively constant condition of properties such as temperature or pH
The sum total of all the biochemical reactions in an organism
a chemical bond that involves the sharing of a pair of electron between atoms
the electromagnetic attractive interaction between polar molecules in which hydrogen (H) is bound
to a highly electronegative atom, such as nitrogen (N), oxygen (O) or fluorine (F). The name hydrogen
bond is something of a misnomer, as it is not a true bond but a particularly strong dipole-dipole
attraction, and should not be confused with a covalent bond (a dipole is just a separation of positive
and negative charges)
Respond to the following on a separate paper.
1. Distinguish between monosaccharides, disaccharides, oligosaccharides, and polysaccharides.
2. Laminaria saccharina is a large brown alga found in high wave action areas on our coast. Read the following
description of this organism, and then explain where its Latin name comes from:
“Just like oarweed, sea belt also looks like long leathery ribbons. However, the fronds are lancet-shaped
with wavy edges. Roots that cling to stones and shells give the seaweed a sturdy base under water. When
wet, the leaves feel slippery due to a kind of mucus. When dried up, a white powdery 'sugar' forms on its
fronds, giving sea belt its nickname sugar kelp. In fact, this seaweed is used as a natural sugar substitute”
(http://eol.org/pages/893180/overview).
3. Draw the basic structure of an amino acid.
4. Draw the basic structure of a deoxynucleotide. How is it different from a ribonucleotide?
5. What are the four nucleotides found in DNA? What are the four nucleotides found in RNA?
6. When we extracted DNA from the blueberries, why did we use detergent?
7. Why is water polar?
8. What characteristics do all living things share? (also be prepared for some thought questions related to this)
9. What do you look for at as you try to decide if a molecule is polar or nonpolar?
10. Fill in the following chart:
Category
Examples of
Examples of
Polar or nonpolar?
Function?
monomers
polymers
carbohydrate
lipid
proteins
Nucleic acids