Nucleic Acids Flashcards
What do you call the transfer of characteristics from generation to generation?
Heredity
True or False
All genes lead to the production of proteins and another type of nucleic acids (RNA)
False
not all genes lead to protein production but all lead to RNA production
Genes are stretches of DNA that are transcribed into RNA
Two types of nucleic acids?
DNA & RNA
what do you call the monomers of nucleic acids?
nucleotides
A nucleotide is composed of three simpler units, what’re they?
- base
- monosaccharide
- phosphate
All of the bases of nucleic acids are ____ because they are heterocyclic aromatic amines.
basic
Two types of bases?
Purines & Pyrimidines
Among the bases of nucleic acids, which of them are purines and which are pyrimidines?
- Purine = A & G
- Pyrimidine = T, C, & U
How does thymine differ from uracil structurally?
methyl group at carbon 5
Which N will lose a hydrogen when the bases of nucleic acids bond with monosaccharides?
diff purine w pyrimidine
- Purine = N-9
- Pyrimidine = N-1
based sa carbon numberings sa rings
also remember that purines are double-ringed while pyrimidine isa lang
Sugar component of RNA is what?
D-ribose
Sugar component of DNA?
2-deoxy-D-ribose
Structurally, which Carbon will have the presence or absence of -OH for it to be classified as a sugar of RNA or DNA?
Carbon 2
RNA = may OH sa carbon 2 (D-ribose)
DNA = H lang nasa carbon 2 (2-deoxy-D-ribose)
the combination of a sugar and base is known as a what?
nucleoside
The bases of purines are linked to carbon number what of the monosaccharide to the nitrogen number what of the base?
C-1 to N-9
The bases of pyrimidines are linked to carbon number what of the monosaccharide to the nitrogen number what of the base?
C-1 to N-1
The bases and monosaccharides are connected via a bond called?
B-N-glycosidic bond
What do you call the nucleoside made of adenine and ribose? what about adenine and deoxyribose?
Adenosine; Deoxyadenosine
what do you call a nucleoside bonded to one, two, or three phosphate groups?
nucleotide
When phosphoric acid forms a ____ bond with nucleoside, the result forms a compound known as a nucleotide
phosphate ester bond
or phosphodiester bond
What do you call 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
What do you call the common currency into which energy gained from good is converted and stored?
ATP
Adenosine 5’-triphosphate
what are the two parts of the primary structure of nucleotides?
- backbone
- bases that are side-chain grps
the backbone of nucleic acids in its primary structure is composed of what?
alternating monosaccharide and phosphate groups
Each phosphate group forms a phosphate ester bond from the ____ carbon of a monosaccharide unit to the ____ carbon of another monosaccharide
3’; 5’
Similar to proteins, we need a convention to tell us which end to start with when we write the sequence of bases and for nucleotides, we will start where?
nucleotide w/ free 5’ terminus
What do you call the arrangement in which two strands of DNA are coiled around each other in a screw-like fashio?
Double helix
In an aqueous environment, the bases point where? The backbone is where?
inward, outward, inside, outside
inward; outside
bases are hydrophobic; sugar-phosphate group is hydrophilic due to its negative charge
Whose rule stated that the DNA bases form hydrogen bonds to another specific base?
A-T; C-G
Chargaff’s rule
from Erwin Chargaff who showed that quantity of A is similar to T and C to G
How many H-bonds can we find in an A-T complementary base pair?
2 hydrogen bonds
How many H-bonds can we find in an C-G complementary base pair?
3 hydrogen bonds
DNA is coiled around proteins called?
histones
Histones are rich in the basic amino acids what?
Lys & Arg
The negatively-charged DNA molecules and positively-charged histones attract one another and form units called ____.
Nucleosomes
What do you call a core of eight histone molecules around which the DNA helix is wrapped?
Nucleosome
Nucleosomes are further condensed into ____ where a 30-nm-wide fiber forms in which nucleosomes are wound in a ____ fashion, with six nucleosomes forming a repeating unit
Chromatin; Solenoid
Chromatin fibers are organized further into loops and arranged into bands to provide the superstructure of ____?
chromosomes
Identify the level of structure
Order or sequence of bases in the polynucleotide sequence which specifies the genetic code
primary structure
Identify the level of structure
ordered arrangement of nucleic acid strands
Secondary structure
Identify the level of structure
3-D arrangement of all atoms of a nucleic acid; referred to as supercoiling
Tertiary structure
Identify the type of nucleic acid base
Compounds that contain a six-membered ring which are parents of C, T, U
Pyrimidine bases
Identify the type of nucleic acid base
Compounds that contain a six-membered ring fused to a five-membered ring which are parent compounds of A & G
Purine bases
What do you call the covalent linkage in which phosphoric acid is esterified to the 3′ hydroxyl of one nucleoside and the 5′ hydroxyl of another nucleoside?
Phosphodiester bonds
3’, 5’-phosphodiester bond
True or False
Nucleotide residues of nucleic acids are numbered from the 5′ end to the 3′ end
True
DNA double helix structure is proposed by who back in 1953?
James Watson and Francis Crick
DNA consists of imaginary cylinder that encloses the DNA in a double helix. This imaginary cylinder is known as?
Grooves
may be major or minor grooves
What do you call the DNA type wherein the 5’ end and 3’ end are joined by phosphodiester bonds?
Circular DNA
Prokaryotic DNA is circular and forms supercoils. What are the two types of supercoils?
Positive & Negative
(+) = more than normal turns of the helix
(-) = fewer than normal turns of the helix
What must be added to a sample of DNA to break the H-bonds and to disrupt the stacking interactions?
Energy
carried out by heat
Denaturation of DNA is via heat then Renaturation is possible on slow cooling
Identify the RNA type
chain of nucleotides where sequence is exactly complementary to DNA after transcription
mRNA
Identify the RNA type
directs amino acid sequence of proteins
mRNA
messenger
Identify the RNA type
transports amino acids to site of protein synthesis
tRNA
transport
Identify the RNA type
combines with proteins to form ribosomes, the site of protein synthesis
the RNA complexed with proteins in ribosomes
rRNA
ribosomal
Identify the RNA type
processing of the initial mRNA transcribed from DNA into a mature form ready to go out of nucleus
snRNA
small nuclear
Identify the RNA type
responsible for splicing mRNA
snRNA
small nuclear
Identify the RNA type
Affects gene expression which is important in growth and development
miRNA
micro
Identify the RNA type
affects gene expression and is used by scientists to knock out a gene being studied
siRNA
small interfering
Identify the RNA type
bind to mRNA and prevent its translation; also used in the treatment of hepa C
miRNA
micro
Identify the RNA type
bind to mRNA but lead to the cleavage of the RNA in question and is also used in the treatment of ebola virus
siRNA
small interfering
what do you call a stretch of DNA that carries the message to direct the synthesis of a protein, tRNA, or mRNA?
Gene
many genes are present in in a DNA molecule, in bacteria this message is ____, while in higher organisms it is ____.
continuous, discontinuous
continuous; discontinuous
What do you call the nucleotide sequences in DNA or mRNA that code for a protein?
Exons
short for expressed sequences
What do you call the nucleotide sequences in DNA or mRNA that do not code for a protein?
Introns
short for intervening sequences
____ are protein-coding regions that must be joined by removing ____, the noncoding intervening sequences.
Exons; Introns
The process of intron removal and exon joining is called what?
splicing
What do you call DNA molecules in which short nucleotide sequences are repeated hundreds or thousands of times? Smaller repetitive sequences?
Satellites; microsatellites
CRISPR stands for what?
clustered regularly interspaced short palindromic repeats
these are repetitive stretches of DNA found in bacteria and archaea
what are the two functions of the DNA in the chromosome?
- DNA reproduction
- information for protein synthesis
What do you call the point in the DNA where replication begins?
origin of replication
or replication fork
Replication is ____ and takes place at the same speed in both directions
hint in bold
bidirectional
One of the syntheses in replication is ____ along the 3’ to 5’ strand and the strand is called the ____ strand
continuous; leading strand
The other strand wherein it runs in the 5’ to 3’ end has its synthesis ____ and the strand is the ____.
discontinuous; lagging strand
The replication process is called ____ because each daughter molecule has one parental strand and one newly synthesized one
semiconservative
When adding a nucleotide to the growing DNA chain, what group acts as a nucleophile to attack the phosphorus adjacent to the sugar in the nucleotide, which will be added to the growing chain?
3’ hydroxyl group
Enumerate the steps of DNA replication
own words
- Opening Up the Superstructure via histone acetylase (+) & (-) differences between histone & nucleotides
- Relaxation of Higher-Order Structures of DNA via topoisomerase to relieve supercoiling or to uncoil
- Unwinding the double helix via helicase then SSB proteins to stabilize strands
- Primers/Primases to add RNA primers
- DNA Polymerase III to build upon primers then Pol I to replace RNA primer w DNA (5’ to 3’ end)
- Ligase to attach okazaki fragments in the lagging strand
Identify the component of replisome
unwinds the DNA double helix
helicase
Identify the component of replisome
synthesizes short oligonucleotides (RNA primers)
primase
Identify the component of replisome
allows the leading strand to be threaded through
clamp protein
Identify the component of replisome
joins the nucleotides by adding free nucleotides in the vicinity of the replication fork to the strands
DNA Polymerase
Identify the component of replisome
joins Okazaki fragments in the lagging strand
ligase
Identify the component of replisome
protects the single-stranded regions from degradation during replication
or stabilization of single strands
Single-stranded binding protein
SSB
Millions of copies of selected DNA fragments can be made within a few hours with high precision by a technique called ____
Polymerase Chain Reaction
PCR
Explain PCR
own words
- heat DNA up to 95oC to unwind double helix
- cool to 60oC to allow primer to bind
- heat up to 70oC to allow polymerase to fill up complementary strands
what do you call the bacteria where its polymerase is isolated and used in PCR?
Thermus aquaticus
lives in hot springs
Taq DNA polymerase is used in PCR
What are the various DNA conformations?
- A-DNA
- B-DNA
- Z-DNA
Identify the RNA pyrimidine bases
- Cytosine
- Uracil
DNA polymerase reactions require what?
a. dUTP
b. Primers
c. dTTP
d. CO2
b & C
- requires primers, dna strand, all deoxyribonucleoside triphosphates, and ribonucleoside triphosphates
What are the functions occurring in exonuclease activities?
- proofreading
- DNA repair
Which DNA polymerase is responsible for repairing and patching DNA?
DNA Pol I
Which DNA Polymerase is responsible for repairing enzymes?
DNA Pol II, IV, & V
Which enzyme is responsible for relaxing the DNA supercoil?
DNA gyrase
topoisomerase other term
Which enzyme is responsible for creating a short section of RNA to act as a primer for DNA synthesis?
Primase
Which enzyme is responsible for the final linking of the DNA base pairs into the newly-formed strand?
DNA ligase
What do you call the proteins responsible for the stabilization of single-stranded regions by binding tightly to them?
SSB
Single-Strand Binding proteins
Which enzyme promotes the unwinding of the DNA double helix by binding at the replication fork?
Helicase
What do you call the part of the Pol III enzyme that opens the sliding clamp and inserts the DNA chain?
It is a pentameric enzyme of a family of ATPases called AAA+ superfam
Clamp Loader
Okazaki fragments latch onto what strand?
Lagging strand
What are the exogenous factors that lead to DNA damage?
- UV radiation
- Ionizing radiation
- Chemical agents
Enumerate the endogenous factors that lead to DNA damage
- Mismatched DNA bases
- Hydrolysis
- Oxidation
- Alkylation
What DNA excision or DNA repair mechanism fixes DNA damage from chemical agents?
Double strand breaks
DSB nga eong nangyayari when u add chemical/s, DNA repair mechanism should be NHEJ (Nonhomologous DNA end-joining but idk hahahha eto ans s quiz e)
What DNA excision or DNA repair mechanism fixes DNA damage from UV radiation?
Nucleotide excision repair
What DNA excision or DNA repair mechanism fixes DNA damage from hydrolysis?
Base excision repair
hydrolysis, alkylation, and oxidation all under BER
What DNA excision or DNA repair mechanism fixes DNA damage from wrongly-paired DNA bases?
Mismatched repair system