Unit 4: Nucleotides, Nucleic Acids, and Heredity Flashcards
Identify location/structure:
where transmission of hereditary information took place
(19th century)
chromosomes
Enumerate:
chromosomes composition
- histones
- nucleic acids
Identify structure:
carry hereditary information (1940s)
deoxyribonucleic acid (DNA)
Enumerate:
2 kinds of nucleic acids
- ribonucleic acid (RNA)
- deoxyribonucleic acid (DNA)
Identify the term:
Both RNA and DNA are polymers from monomers called?
nucleotides
Enumerate:
nucleotide composition
- (nucleotide) base
- monosaccharide (sugar)
- phosphate
Identify structure:
bicyclic in nature;
two rings are fused together
purines
Enumerate:
purines (nitrogenous bases)
- adenine
- guanine
Identify structure:
has only one 6-carbon rings
pyrimidine
Enumerate:
pyrimidine (nitrogenous bases)
- cytosine
- thymine (DNA)
- uracil (RNA)
Identify the structure:
a compound that consists of D-ribose or 2-deoxy-D-ribose bonded to a purine or pyrimidine base by β-glycosidic bond
nucleoside
Identify the structure:
links the nucleobase and sugar
β-glycosidic bond
Identify the nitrogenous bases once bound to the sugar:
uracil
adenine
guanine
cytosine
thymine
uracil - uridine
adenine - adenosine
guanine - guanosine
cytosine - cytidine
thymine - thymidine
Identify the structure:
a nucleoside in which a molecule of phosphoric acid is esterified with an -OH of the monosaccharide, most commonly either at the 3’ or the 5’ -OH
nucleotide
Identify the structure:
serves as a common currency into which energy gained from food is converted and stored
Adenosine 5’ triphosphate (ATP)
Identify the DNA structure level:
the sequence of nucleotides, beginning with the nucleotide that has the free 5’ terminus
primary structure
Identify the DNA structure level:
the ordered arrangement of nucleic acid strands
secondary structure
Identify the structure:
a type of secondary structure of DNA in which 2 polynucleotide strands are coiled around each other in a screw-like fashion
double helix
Enumerate:
2 types of grooves present based on the DNA double helix model
- major grooves
- minor grooves
Identify the structure:
larger spaces in the DNA double helix structure that serve as binding sites to biomolecules
major grooves
Identify the structure:
smaller spaces in the DNA double helix structure that serve as binding sites to small molecules or organic molecules
minor grooves
Identify the number of hydrogen bonds:
A and T pair formation
2 hydrogen bonds
Identify the number of hydrogen bonds:
G and C pair formation
3 hydrogen bonds
Identify the term:
main stabilizing force of the DNA double helix
canonical base pairing
Identify the structure:
proteins where DNA is coiled around
histones
Identify the structure:
formed when the negatively charged DNA molecules and positively charged histones attract one another
nucleosomes
Identify the structure:
a core of 8 histone molecules around which the DNA helix is wrapped
nucleosomes
Identify the structure:
nucleosomes are further condensed into _________
chromatin
Identify the structure:
chromatin fibers are organized into loops, and the loops into bands that provide the superstructure of ___________
chromosomes
Identify the difference in structure:
DNA and RNA based on bases
DNA bases: A, G, C, T
RNA bases: A, G, C, U
Identify the difference in structure:
DNA and RNA based on sugar
DNA sugar: 2-deoxy-D-ribose
RNA: D-ribose
Identify the difference in structure:
DNA and RNA based on strands
DNA: double-stranded
RNA: single-stranded
Identify the process:
yields two DNA molecules identical to the original one, ensuring transmission of genetic information to daughter cells with exceptional fidelity
replication
Identify the process:
the sequence of bases in DNA is recorded as a sequence of complementary bases in a single-stranded mRNA molecule
transcription
Identify the process:
three-base codons on the mRNA corresponding to specific amino acids direct the sequence of building a protein; these codons are recognized by tRNAs carrying the appropriate amino acids
translation
Identify the structure:
“machinery” for protein synthesis
ribosomes
Identify the type of RNA:
size: small
function: transports amino acids to site of protein synthesis
transfer RNA (tRNA)
Identify the type of RNA:
size: several kinds; variable in size
function: combines with proteins to form ribosomes; acts as a catalyst; a component of ribozymes
ribosomal RNA (rRNA)
Identify the type of RNA:
size: variable
function: directs amino sequence of proteins; produced during transcription
messenger RNA (mRNA)
Identify the type of RNA:
size: small
function: processes initial mRNA to its mature form in eukaryotes
small nuclear RNA (snRNA)
Identify the type of RNA:
size: small
function: affects gene expressions; important in growth and development
micro RNA (miRNA)
Identify the type of RNA:
size: small
function: affects gene expression; used by scientists to knock out gene being studied
small interfering RNA (siRNA)
Identify the type of RNA:
size: variable
function: involved in activating or silencing specific genes
long non-coding RNA (lncRNA)
Identify the type of RNA:
size: small
function: protects animal genomes against transposons
piwi-associated RNA (piRNA)
Identify the type of RNA:
size: variable
function: acts as miRNA sponge, controlling the effects of miRNA
circular RNA
Identify the structure:
a segment of DNA that carries a base sequence that directs the synthesis of a particular protein, tRNA, or mRNA
gene
Identify the structure:
a section of DNA that, when transcribed, codes for a protein or RNA
exon
Identify the structure:
a section of DNA that does not code for anything functional
intron
Enumerate:
2 functions of DNA in the chromosomes
- reproduces itself (replication)
- supplies the information necessary to make all the RNA and proteins in the body, including enzymes
Identify the term:
a point in the DNA called the origin of replication where replication begins
replication fork
Enumerate:
DNA replication steps
- DNA structure opening
- Relaxation of higher-order structure
- Unwinding of the double helix
- Primer synthesis by primases
- DNA synthesis by DNA polymerase
- Ligation of DNA fragments
Identify the enzyme:
temporarily introduce either single- or double-strand breaks in DNA
topoisomerase or gyrases
Identify the enzyme:
special unwinding proteins that attach to one DNA strand and cause the separation of the double helix (unzips)
helicase
Identify the structure:
short 4 to 15 nucleotides long–RNA oligonucleotides synthesized from ribonucleoside triphosphates
primers/ primases
Identify the structure:
needed to initiate the primate-catalyzed synthesis of both daughter strands
primers/ primases
Identify the enzyme:
joins the nucleotide backbone
polymerase
Identify the enzyme:
joins the Okazaki fragments and any nicks remaining
ligase
Identify the term:
a high-precision technique that makes millions of copies of selected DNA fragments within a few hours
polymerase chain reaction (PCR)
Identify the enzyme (DNA amplification):
extends the primers in each direction as individual nucleotides are assembled and connected on the template DNA, creating 2 copies
polymerase
T/F:
Nucleosides have a phosphate group.
False
Identify the level of structure in NA:
order of bases in the polynucleotide sequence
primary structure
Identify the level of structure in NA:
specifies the genetic code
primary structure
Identify the level of structure in NA:
three-dimensional conformation of the polynucleotide backbone
secondary structure
Identify the level of structure in NA:
supercoiling of the molecule
tertiary structure
Identify the level of structure in NA:
interaction with other classes of macromolecules, such as proteins
quaternary structure
Identify the compound:
nitrogen-containing aromatic compounds that make up the coding portion of nucleic acids
nucleic acid bases
T/F:
polymerization of nucleotides produces nucleic acids
true
Identify the NA:
biopolymer that consists of a backbone of alternating units of 2-deoxy-D-ribose and phosphate
deoxyribonucleic acid (DNA)
T/F:
nucleotide residues of nucleic acids are numbered from the 3’ end to the 5’ end
false;
5’ to 3’
Identify the level of structure in DNA:
sequence of bases along the pentose-phosphodiester backbone of a DNA molecule
primary structure
Identify the level of structure in DNA:
ordered arrangement of nucleic acid strands
secondary structure
Identify the level of structure in DNA:
three-dimensional arrangement of all atoms of a nucleic acid
tertiary structure
Identify the level of structure in DNA:
referred to as supercoiling
tertiary structure
Enumerate:
DNA conformations
- B-DNA
- A-DNA
- Z-DNA
Identify the DNA conformation:
considered the normal form;
right-handed helix
B-DNA
Identify the number of base pairs per turn of the helix:
B-DNA
10 base pairs
Identify the DNA conformation:
right-handed helix but thicker than B-DNA; not found in in-vivo techniques
A-DNA
Identify the number of base pairs per turn of the helix:
A-DNA
11 base pairs
Identify the DNA conformation:
left-handed double helix that may play a role in regulation of gene expression
Z-DNA
T/F:
bases are hydrophobic and interact with each other via hydrophobic bonding
true
T/F:
many bases adopt a propeller twist
true
Identify the structure:
extra twists in closed circular DNA
DNA supercoils
Identify the structure:
type of double-stranded DNA in which the 5’ and 3’ ends of each strand are joined by phosphodiester bonds
circular DNA
T/F:
prokaryotic DNA is an example of circular DNA that forms supercoils
true
Identify the type of supercoil:
circular DNA with fewer than normal number of turns of the helix
negative supercoils
Identify the type of supercoil:
circular DNA with more than normal number of turns of the helix
positive supercoils
Identify the enzyme:
relax supercoiling in closed circular DNA
topoisomerases
Identify the class of topoisomerase:
cut the phosphodiester backbone of one strand, pass the other end through, and reseal
Class I
Identify the class of topoisomerase:
cut both strands, pass some of the remaining DNA helix between the cut ends, and reseal
Class II
Identify the enzyme:
bacterial topoisomerase that introduces negative supercoils into DNA
DNA gyrase
Identify the structure:
result of supercoiling in eukaryotic DNA
chromatin
Explain:
why structure and spacer regions (spacing) are important in chromatin function
affects the rate of mutation
Identify the term:
must be added to a sample of DNA to break the hydrogen bonds and to disrupt the stacking interactions
energy
(heating in a solution)
Identify the process:
heat denaturation of DNA
melting
T/F:
renaturation is possible on slow heating
false;
slow cooling
Identify the NA:
consists of long, unbranched chains of nucleotides joined by phosphodiester bonds between the 3’ -OH of one pentose and the 5’ -OH of the next
ribonucleic acid (RNA)
Identify the type of RNA:
single-stranded polynucleotide chain between 73 and 94 nucleotide residues long; carries an amino acid at its 3’ end
tRNA
Identify the type of RNA:
found in the site of protein synthesis
rRNA
Identify the type of RNA:
initially formed as a larger precursor molecule called heterogenous nuclear RNA (hnRNA)
mRNA
Identify the type of RNA:
carries coded genetic information from DNA to ribosomes for the synthesis of proteins
mRNA
Identify the type of RNA:
complexes with proteins and forms small nuclear ribonucleoprotein particles (snRNPs)
snRNA
Identify the structure:
protein-RNA complexes found in the nucleus that aid in processing RNA molecules for export to the cytosol
small nuclear ribonucleoprotein particles (snRNPs)
Identify the structure:
help with processing of the initial mRNA transcribed from DNA into a mature form
small nuclear ribonucleoprotein particles (snRNPs)
T/F:
short stretches of RNA do not have control over gene expression
false;
have enormous control
Identify the type of RNA:
bind to mRNA and prevent its translation
micro RNAs (miRNAs)
Identify the type of RNA:
bind to mRNA but lead to the cleavage of the RNA in question
small interfering RNAs (siRNAs)
