Nucleic Acids Flashcards
structure in the cell nucleus thought to be the carrier of genetic information
chromosomes
portion of a chromosome that controls a specific ineritable trait
gene
sum of all genes
genome
one of the major macromolecules in the body responsible for storing and expressing genetic information
nucleic acids
double-stranded, stores genetic information and protein-coding information, transfers information to daughter cells
DNA
sugar in DNA
2’-deoxyribose
4 nucleotide bases in DNA
[CATG]
(1) Cytosine
(2) Adenine
(3) Thymine
(4) Guanine
single-stranded
RNA
sugar in RNA
ribose
4 nucleotide bases in RNA
[UAGC]
(1) Uracil
(2) Adenine
(3) Guanine
(4) Cytosine
single building block of nucleic acids
nucleotide
parts of the nucleotide:
[PNS]
(1) Phosphate group
(2) Nitrogenous base
(3) Sugars
the sugar in DNA, 2’-deoxyribose, means that
an oxygen atom is missing from the C2 position of ribose
two types of bases and examples:
[PURe As Gold; CUT the PY]
Purine
- Guanine
- Adenine
Pyrimidine
- Cytosine
- Uracil
- Thymine
a nitrogenous base that has two fused nitrogen-containing ring
purine
a nitrogenous base that has one nitrogen-containing ring
pyrimidine
SUGAR + BASE =
NUCLEOSIDE
Sugar + base = nucleoSide
base pairing in DNA
A=T (DNA)
A=U (RNA)
G=C (DNA and RNA)
bond connecting the sugar’s 5C atom and nitrogenous base
glycosidic bond
examples of nucleosides:
[GADDUCT]
Guanosine
Adenosine
Deoxyadenosine
Deoxyguanosine
Uridine
Cytidine
Thymidine
NUCLEOSIDE + PHOSPHATE =
NUCLEOTIDE
nucleoside + phosphaTe = nucleoTide
monomers of the DNA and RNA polymers
nucleotides
each nucleotide is a _________ of a nucleotide
phosphodiester
nucleotides are named by adding ___ at the end of the nucleoside
5’-monophosphate
nucleotides can add additional phosphate groups to form _______
diphosphate or triphosphate esters
two phosphate groups
adenosine diphosphate
phosphate group is linked to the __ carbon of the same sugar unit and simultaneously to the __ carbon of the next sugar unit
5’ to 3’
a nucleotide is linked to the __ of the next nucleotide
hydroxyl group at the 3’-carbon
how many hydrogen bonds are present between adenine and thymine?
2
how many hydrogen bonds are present between cytosine and guanine?
3
backbone of nucleic acid
sugar and phosphate
what is the bond between base pairs/bond that holds the nitrogenous base of one strand to that of another?
hydrogen bonds
one end of DNA has 5’-monophosphate and the other has a 3’ hydroxyl group. what characteristic does DNA exhibit?
polarity
this states that (A and T) and (G and C) are present in equimolar quantities
Chargaff’s Rule
who obtained x-ray diffraction photographs based on x-ray crystallography to analyze DNA structure, and found a cross in the center of the DNA structure?
Rosalind Franklin and Maurice Wilkins
the ratio of correspondence between purine and pyrimidine
1:1
are bases hydrophobic or hydrophilic?
hydrophobic
that’s why bases are located inside the sugar and phosphate backbone, which are exposed to the aqueous environment
the polarity of two DNA strands run opposite of each other. this means that DNA strands are
antiparallel
what force of attraction allows DNA and histones to combine to form nucleosomes?
electrostatic (ionic) forces
in a nucleosome, _ histones form a ____, which a ___-base pair DNA double helix is wound
8, core, 147
types of RNA:
[MRT]
Messenger RNA (mRNA)
Ribosomal RNA (rRNA)
Transfer RNA (tRNA)
RNA that codes for proteins and amino acid sequences
mRNA
how many mRNA bases are needed to form a codon, which corresponds to specific amino acids?
3
RNA that forms the core of the structure that makes proteins?
rRNA
RNA that matches codes for amino acids on mRNA and positions the right amino acid in place during protein synthesis
tRNA
it carries genetic information from the DNA in the nucleus directly to the cytoplasm
mRNA
how many bases does mRNA usually contain?
500-4500 bases
also called “transcripts”
mRNA
how many nucleotides does rRNA contain?
100-3000 nucleotides
2 subunits of ribosomes
(1) large: catalyzes peptide bond formation
- contains 3 ribosomal RNA molecules
(2) small: binds mRNA and tRNA
- contains 1 ribosomal RNA molecule
the subunits of ribosomes are separated in the _____ and joins at the site of ______ in protein synthesis
cytoplasm, initiation
how many nucleotides does tRNA contain?
73-93 nucleotides per chain
how many tRNA are different from each of the 20 amino acids?
at least one
characteristic of a tRNA
clover leaf shape
some bases form weak chemical bonds with each other, resulting to folding of the tRNA into loops
how many bases does an anticodon contain?
3
what catalyzes the splicing of mRNA?
ribozyme
genetic information flows in how many directions?
one direction
this is the template or starting sequence that is copied into RNA, that is then used to make protein
DNA
DNA -> RNA -> protein
2 steps in the transmission of information
transcription and translation
this is called the transcript
RNA chain
product of transcription
mRNA chain
where does transcription occur?
nucleus and cytoplasm
in this process, information encoded in an mRNA molecule is used to assemble a specific protein
translation
transcription is carried out by
RNA polymerase
translation is performed on
ribosomes
replication is carried out by
DNA polymerase
what copies RNA into DNA?
reverse transcriptase
coding or expressed sequences
exons
noncoding or intervening sequences
introns
these should be removed in the mRNA
what removes introns and join all exons together?
ribozyme
