Unit 1 test Flashcards
Negatively charged ions are called:
anions
A(n) _____ is an atom or molecule with an electrical charge resulting from the gain or loss of one or more electrons.
ion
Positively charged ions are called:
cations
Table salt is the common name for which chemical compound?
sodium chloride
A substance that cannot be broken down into other substances by ordinary chemical procedures is known as a(n) _______ .
atom
Electrical attraction between polarized molecules creates a:
hydrogen bond
The interaction between water molecules and other polar molecules is called:
adhesion
12C (read as “carbon 12”), 13C (carbon 13), and 14C (carbon 14) are all isotopes of the element carbon. The difference between these isotopes is the number of _______ associated with each atom.
neutrons
An acid is a solution that:
releases H+
When potassium hydroxide is mixed with water, hydroxide ions are RELEASED. How could you define this solution?
acid
Which of the following properties of water is NOT due to hydrogen bonding?
the bonds between hydrogen and oxygen atoms of a single water molecule
Which of the following statements regarding matter is false?
All matter has mass.
All life is composed of matter.
All matter is composed of elements.
All matter exists in the form of compounds.
All matter exists in the form of compounds
Which of the following is a characteristic that makes radioactive tracers useful in medical diagnoses and clinical research?
Living cells distinguish radioactive tracers from nonradioactive tracers.
They are incorporated into reaction in living material.
They can form chemical bonds.
They can break chemical bonds.
they are incorporated into reaction in living material
When the atoms involved in a chemical bond have the same electronegativity, what type of bond results?
nonpolar covalent bond
A(n) ______ bond results from the unequal sharing of electrons.
polar covalent
The construction of macromolecules usually requires:
the loss of water molecules
Which of the following amino acids is NOT hydrophobic?
alanine
threonine
isoleucine
tryptophan
threonine
6-carbon sugars are called:
hexoses
What is a simple example of a carbohydrate?
sugar
The lipids that form the main structural component of cell membranes are _____ .
phospholipids
Inhibitors that bind noncovalently to enzymes and alter the shape of the active site are called:
noncompetitive inhibitors
Carbohydrates are mainly used in our bodies _____ .
as fuel
Cellulose differs from starch in that:
most animals cannot break down cellulose, whereas starch is easily digested.
Manufacturers make vegetable oils solid or semisolid by _____.
adding hydrogens
Small organic molecules that are chemically modified in the process of enzymatic functioning are called:
coenzymes
A molecule that does not have a net electrical charge at one end as opposed to the other is:
a nonpolar molecule
Radioactive isotopes:
can be used in conjunction with PET scans to diagnose diseases
The bonds between water molecules are responsible for:
cohesion
A base is a solution that:
accept H+
H2O is a/n:
compound
A polar covalent bond:
results from the unequal sharing of electrons
Ions are formed when:
atoms gain or lose one or more electrons
When a solution is capable of accepting H+ ions, it is defined as a(n):
base
Which of the following is not a property of liquid water?
Its heat of vaporization is lower than that for most other substances
An ion is:
an atom with either a positive or negative charge.
Hydrogen bonds are formed by the:
electrical attraction between polarized molecules
A(n) _______ forms when two atoms share electrons.
covalent bond
How are ionic bonds formed?
In ionic bonds, one atom gives up an electron to a second atom.
The nucleus of an atom is composed of:
protons and neutrons
The bond between the oxygen atom and a hydrogen atom in a water molecule is a(n):
covalent
Which of the following is NOT a hexose?
sucrose
mannose
ribose
glucose
ribose
________ bonds link multiple monomers into long polymers.
covalent
Kinases:
catalyze the addition of phosphate groups to their substrates
Proteins are linear molecules. Which functional group is present at the start of all proteins?
amino group
Peptide bonds are formed between:
amino and carboxyl groups from adjacent amino acids
Starch:
is used for long term storage of energy in plants
Inorganic molecules that bind with enzymes and assist enzymatic functions are called:
cofactors
what does not influence the tertiary structure of a protein?
peptide bonds
Which of the following prefixes means “several”?
oligo-
Amino acids are the monomers of which macromolecule?
proteins
Carbon is an important element for biology because:
of a variety of carbon skeletons and functional groups that can be built on them.
If a molecule can be easily dissolved in water, it is likely:
polar
Which of the following elements is the most abundant in living organisms?
hydrogen
Which subatomic particle has a positive charge?
protons
Compounds:
are substances composed of two or more different elements
The interaction between water molecules and other polar molecules is called:
adhesion
The atomic number of an atom is determined by:
number of protons in an atom
Which of the following statements about covalent bonds is FALSE?
A covalent bond is stronger than a hydrogen bond.
A covalent bond can form between atoms of the same element.
Only a single covalent bond can form between two atoms.
A covalent bond can form between atoms of different elements.
only a single covalent bond can form between two atoms
Atoms of the same element that have different atomic masses are called:
isotopes
Chemically defined, a polar molecule is one that:
has an unequal charge distribution
Which of the following is not an example of a lipid?
Vitamin C
testosterone
Vitamin E
olive oil
cholesterol
Vitamin C
ATP is a:
nucleotide
Reactions that release energy into the environment are called:
catabolic
Condensation reactions:
link monomer subunits into macromolecule polymers
What is the general function of enzymes within a cell?
to speed up chemical reactions
Which of the following lists contains only polysaccharides?
cellulose, starch, and glycogen
fructose, cellulose, and glucose
starch, amino acids, and glycogen
glucose, starch, and cellulose
cellulose, starch, and glycogen
Which of the following functional groups is negatively charged in cellular environments?
amino
aldehyde
phosphate
hydroxyl
phosphate
In the human body, glycogen is stored primarily in:
liver and skeletal muscles
The secondary structure of a protein is influenced by:
hydrogen bonds
What is the main sugar used by cells for energy?
glucose
Alpha-helices are stabilized by:
Hydrogen bonding within the peptide backbond
When one of the atoms involved in a chemical bond has a much higher electronegativity than the other atom, what type of bond results?
a polar covalent bond
Ionic bonds are formed by:
electrical attraction between opposing charges
When potassium hydroxide is mixed with water, hydroxide ions are released. How could you define this solution?
basic
