MCDB Exam 2 with complete solutions
nucleic acids - Correct Answers -a macromolecule composed of nucleotide monomers
nucleotides - Correct Answers -a molecule consisting of a 5-carbon sugar, one or more
phosphate groups, and a nitrogenous base
ribonucleotides - Correct Answers -a nucleotide consisting of a ribose sugar, one or
more phosphates, and one of four nitrogen-containing bases: adenine, guanine,
cytosine, or uracil
deoxyribonucleotides - Correct Answers -a nucleotide consisting of a deoxyribose
sugar, one or more phosphates, and one of four nitrogen-containing bases: adenine,
guanine, cytosine, or thymine
carrier proteins - Correct Answers -a transmembrane protein that facilitates diffusion of
a small molecule across a membrane by a process involving a reversible change in the
shape of a protein
active transport - Correct Answers -the movement of ions or molecules across a
membrane in a single direction, often against a gradient; requires energy and decreases
entropy
pump - Correct Answers -any membrane protein that uses energy to change shape and
power the active transport of a specific ion or molecule across a membrane in a single
direction, often against its gradient
sodium-potassium pump - Correct Answers -a transmembrane protein that uses the
energy of ATP to move sodium ions out of the cell and potassium ions into the cell,
against electrochemical gradients; 3 Na+ ions out, 2 K+ ions in
secondary active transport - Correct Answers -transport of an ion or molecule in an
defined direction made possible by the transport of another ion or molecule being
moved along its gradient; also called cotransport
purines - Correct Answers -double-ringed nitrogenous bases (adenine and guanine)
pyrimidines - Correct Answers -single-ringed nitrogenous bases (cytosine, uracil, and
thymine)
, phosphodiester linkage - Correct Answers -forms when the phosphate group of one
nucleotide condenses with the hydroxyl group on the sugar of another nucleotide
X-ray crystallography - Correct Answers -a technique for determining the 3D structure of
large molecules by analyzing the diffraction patterns produced by x-rays beamed at
crystals of the molecule
antiparallel - Correct Answers -described the opposite orientation of nucleic acid
strands; one running 3'-5' and the other 5'-3'
double helix - Correct Answers -the secondary structure of DNA, consisting of 2
antiparallel DNA strands wound around each other
complementary base pairing - Correct Answers -the association between specific
nitrogenous bases of nucleic acids stabilized by hydrogen bonding
base stacking - Correct Answers -describes the interactions that form between adjacent
base pairs in nucleic acid strands of a double helix (consists of hydrophobic and van der
Waals interactions)
template strand - Correct Answers -a strand of DNA/RNA used to make a new,
complementary strand
complementary strand - Correct Answers -a strand of RNA/DNA with a base sequence
that forms via complementary base pairing with the template strand
primary structure of DNA - Correct Answers -sequence of deoxyribonucleotides; bases
are A, T, G, C
secondary structure of DNA - Correct Answers -two antiparallel strands twist into a
double helix, stabilized by hydrogen bonding, hydrophobic interactions, and van der
Waals interactions
tertiary structure of DNA - Correct Answers -double helical DNA forms compact
structures by wrapping around histone proteins or twisting into supercoils
primary structure of RNA - Correct Answers -sequence of ribonucleotides; bases are A,
U, G, C
secondary structure of RNA - Correct Answers -most commonly, a single strand folds
back on itself to form a double-helical "stern" and an unpaired "loop"
tertiary structure of RNA - Correct Answers -secondary structures fold to form a wide
variety of distinctive three-dimensional shapes
nucleic acids - Correct Answers -a macromolecule composed of nucleotide monomers
nucleotides - Correct Answers -a molecule consisting of a 5-carbon sugar, one or more
phosphate groups, and a nitrogenous base
ribonucleotides - Correct Answers -a nucleotide consisting of a ribose sugar, one or
more phosphates, and one of four nitrogen-containing bases: adenine, guanine,
cytosine, or uracil
deoxyribonucleotides - Correct Answers -a nucleotide consisting of a deoxyribose
sugar, one or more phosphates, and one of four nitrogen-containing bases: adenine,
guanine, cytosine, or thymine
carrier proteins - Correct Answers -a transmembrane protein that facilitates diffusion of
a small molecule across a membrane by a process involving a reversible change in the
shape of a protein
active transport - Correct Answers -the movement of ions or molecules across a
membrane in a single direction, often against a gradient; requires energy and decreases
entropy
pump - Correct Answers -any membrane protein that uses energy to change shape and
power the active transport of a specific ion or molecule across a membrane in a single
direction, often against its gradient
sodium-potassium pump - Correct Answers -a transmembrane protein that uses the
energy of ATP to move sodium ions out of the cell and potassium ions into the cell,
against electrochemical gradients; 3 Na+ ions out, 2 K+ ions in
secondary active transport - Correct Answers -transport of an ion or molecule in an
defined direction made possible by the transport of another ion or molecule being
moved along its gradient; also called cotransport
purines - Correct Answers -double-ringed nitrogenous bases (adenine and guanine)
pyrimidines - Correct Answers -single-ringed nitrogenous bases (cytosine, uracil, and
thymine)
, phosphodiester linkage - Correct Answers -forms when the phosphate group of one
nucleotide condenses with the hydroxyl group on the sugar of another nucleotide
X-ray crystallography - Correct Answers -a technique for determining the 3D structure of
large molecules by analyzing the diffraction patterns produced by x-rays beamed at
crystals of the molecule
antiparallel - Correct Answers -described the opposite orientation of nucleic acid
strands; one running 3'-5' and the other 5'-3'
double helix - Correct Answers -the secondary structure of DNA, consisting of 2
antiparallel DNA strands wound around each other
complementary base pairing - Correct Answers -the association between specific
nitrogenous bases of nucleic acids stabilized by hydrogen bonding
base stacking - Correct Answers -describes the interactions that form between adjacent
base pairs in nucleic acid strands of a double helix (consists of hydrophobic and van der
Waals interactions)
template strand - Correct Answers -a strand of DNA/RNA used to make a new,
complementary strand
complementary strand - Correct Answers -a strand of RNA/DNA with a base sequence
that forms via complementary base pairing with the template strand
primary structure of DNA - Correct Answers -sequence of deoxyribonucleotides; bases
are A, T, G, C
secondary structure of DNA - Correct Answers -two antiparallel strands twist into a
double helix, stabilized by hydrogen bonding, hydrophobic interactions, and van der
Waals interactions
tertiary structure of DNA - Correct Answers -double helical DNA forms compact
structures by wrapping around histone proteins or twisting into supercoils
primary structure of RNA - Correct Answers -sequence of ribonucleotides; bases are A,
U, G, C
secondary structure of RNA - Correct Answers -most commonly, a single strand folds
back on itself to form a double-helical "stern" and an unpaired "loop"
tertiary structure of RNA - Correct Answers -secondary structures fold to form a wide
variety of distinctive three-dimensional shapes
