Microbiology Homework Chapter 2 Study Guide
Nucleosides differ from nucleotides in that nucleosides _____.
are missing a phosphate
An acid dissociates in water to release
both anions and hydrogen ions.
Amino acids can combine with either hydroxyl or hydrogen ions. As a result, they can function as
buffers
Which of the following is NOT a normal function of nucleotides?
building blocks of proteins
Which of the following are examples of pyrimidines?
cytosine and thymine
A(n) ________ is an arrangement of atoms found in a variety of macromolecules and serves as their primary reactive end.
functional group
Which of the following is an example of a polysaccharide?
glycogen
Cell markers composed of both carbohydrate and lipid molecules are known as (glycoproteins/glycolipids/glycogen).
glycolipids
The double-strands of DNA result from the formation of ________ between the bases.
hydrogen bonds
A chemical reaction in which a water molecule is a reactant is known as a (dehydration/hydrolysis) reaction.
hydrolysis
The reverse of a dehydration synthesis reaction is a(n) ________ reaction.
hydrolytic
Radioactive iodine is sometimes used to treat thyroid cancer. This is an example of the use of (isotopes/elements/radiation) in medical treatment.
isotopes
The (atoms/isotopes/stereoisomers) of an element vary in the number of neutrons in the nucleus.
isotopes
Methane is classified as a compound because __________.
it contains atoms of more than one element
Pure water has a neutral pH because __________.
it dissociates into equal numbers of hydrogen and hydroxyl ions
Which of the following is a property of water?
it has a high capacity for heat.
All of the following are components of an amino acid EXCEPT a(n)
pentose group
Each nucleotide is composed of a(n) _____.
pentose sugar, phosphate, and nitrogenous base
A(n) ________ is a compound that dissolves into anions and cations in water.
peptidoglycan
Which of the following is not a type of lipid?
peptidoglycan
Lipids found in the cytoplasmic membranes of all eukaryotic cells are
phospholipids
A protein is a ________ of amino acids.
polymer
DNA is composed of repeating units of sugars, phosphates, and nucleic acids. This is an example of a
polymer
TRUE or FLASE: The long-term chemical energy storage molecules in plants are steroids.
False
TRUE or FLASE: The smallest chemical units of matter are elements
False
The nucleotide _____ is an important signaling molecule within many cells.
cyclic adenosine monophosphate
If you know that sodium chloride molecules contain ionic bonds, which of the following electronegativity values would be appropriate for the elements sodium and chlorine?
0.9 and 3.0
Which of the following is an organic compound? H2O, C6H12O6, CO2, O2, NaCl
C6H12O6
Which of the following is NOT true of hydrogen bonds?
Hydrogen bonds are important only in the interaction between water molecules
Which of the following is a molecule but NOT a compound? CO2, O2, H2O, CH4
O2 isn't a compound because it is made of only one element
What is the common trait of all lipids?
They are at least partially hydrophobic
Which of the following is NOT a characteristic of saturated fats?
They contain at least one double bond
Which of the following is NOT a characteristic of phospholipids?
They contain fatty acids that associate with water.
TRUE or FALSE: Dehydration synthesis is a common feature of polymer production in cells.
True
TRUE or FALSE: Salts are produced from exchange reactions in which acids and bases neutralize each other.
True
All of the following are associated with ATP molecules EXCEPT
a long-term energy supply.
The type(s) of bond produced when atoms share electrons equally is/are
a nonpolar covalent bond
Which of the following is a bond in which electrons are shared unequally?
a polar covalent bond
The type(s) of bond produced when atoms with somewhat different electronegativities share electrons is/are
a polar covalent bond.
The valence of an atom represents its
ability to interact with other atoms
A(n) (catalyst/enzyme/intermediate) is any molecule that speeds up a chemical reaction.
catalyst
When a base dissolves in water it releases a(n) (anion/cation/hydrogen ion).
cation
An unbranched polymer composed of simple sugars is
cellulose
KH2PO4 acts as a buffer by __________.
combining with hydrogen ions
Catabolism includes all of the following types of reactions EXCEPT __________.
dehydration synthesis reactions
A synthesis reaction is also considered which of the following types of reactions?
endothermic
A phosphate is moved from one molecule to another. This is an example of a/an ________ reaction.
exchange
Decomposition reactions are commonly ________ reactions.
exothermic
Steroids are (branched/multi-ringed/unbranched) hydrocarbons.
multi-ringed
A(n) (nonpolar/polar/ionic/hydrogen) bond is one in which electrons are shared equally between atoms.
nonpolar
A nitrogenous base composed of two rings is a (purine/pyrimidine/ribose).
purine
Which of the following is found in nucleic acids?
purines
An endothermic reaction __________.
requires energy
Which of the following is found in RNA but not DNA?
ribose
The difference between ribose sugars and deoxyribose sugars is that _____.
ribose sugars have an extra oxygen atom
The folding of a polypeptide into a three-dimensional shape is its (secondary/tertiary/quaternary) structure.
tertiary
During the formation of a nucleic acid, such as DNA, the phosphate group of a new nucleotide covalently binds to _____ of the existing string of nucleotides.
the 3' carbon
All of the following bases are found in RNA molecules EXCEPT
thymine
Organisms use carbohydrates in all of the following ways EXCEPT
to keep membranes flexible at low temperatures
Mycobacterium tuberculosis is resistant to drying due to the presence of ________ in its cell wall.
waxes
The high amount of energy stored within a molecule of the nucleotide adenosine triphosphate may be found _____.
within the phosphate-phosphate bonds
