Nucleic Acids Flashcards
make up nucleic acids
nucleotides
3 components of nucleotide
phosphate
5 carbon sugar
nitrogenous base
example of 5 carbon sugar
ribose
5 carbon sugar present in DNA
deoxyribose
4 nitrogenous bases
adenine
guanine
cytosine
thymine
how are nucleotides linked together
by dehydration synthesis or polymerisation reactions betrween one sugar nucleotide and phosphate group of second nucleotide
forms the structural framework of nucleic acids, including DNA and RNA.
sugar phosphate backbone
DNA is composed of two strands arranged as a right handed ___
helix
orientation of the strands of a double helix
anti-parallel
what kind of bonds hold the two strands of double helix
hydrogen bonds
Guanine form hydrogen bonds with ___
cytosine
Adenine bonds with ___
thymine
RNA differs from DNA because it contains the sugar
ribose
nitrogenous base present in RNA
uracil
RNA is usually ___ and does not form ___
single stranded
helix
which is more stable
RNA/DNA
RNA
stores the information to construct a protein
DNA
regulates expression of information during protein synthesis
RNA
modified nucleotide that plays essential role in energy processing within cells
ATP
ATP is composed of
adenine
ribose
3 phosphate
bonds within ATP bonds are
high energy bonds
which phosphate group in ATP is removed when energy is needed
terminal phosphate
formed when terminal phosphate is removed in ATP
adenosine diphosphate
are biopolymers that carry information inside cells
nucleic acids
two main kinds of nucleic acids
DNA
RNA
function of DNA
stores the genetic information for a cell and is inherited and passed down through generations of organisms.
function of RNA
copy of particular sections of genetic information, which are used to direct the synthesis of proteins during gene expression.
act as templates for making copies of themselves.
nucleic acids
monomer of nucleic acids
nucleotide
three sections of nucleotide
sugar
base
phosphate group
all three parts of the nucleotide have what bonds
covalent bonds
how many hydrogen bonds has G-C has
3
how many hydrogen bonds does T-A have
2
So, each nucleic acid (either DNA or RNA) consists of repeating subunits, called
nucleotide
what kind of sugar is in DNA
2-deoxyribose
In 2-deoxyribose, an oxygen atom is lost in the –OH group of the ribose at carbon number
2
are formed by joining the hydroxyl (OH) group on the sugar of one nucleotide to the phosphate group of another nucleotide.
polynucleotides
Just like magnets, these polynucleotides have ___ , or different ends - a “top” and a “bottom”.
poles
polynucleotide top pole
phosphate group
polynucleotide bottom pole
OH from a sugar
what designation means that the numbering is present in the sugar and not in the nitrogenous base.
prime (‘)
two categories of nitrogenous bases
purines
pydrimidines
has large, double-ring molecules, and can be found in both DNA and RNA
purines
two purines
adenine
guanine
bases that have single-ring molecules
pyrimidines
example of pyrimidines
cytosine
thymine
uracil
heterocyclic means
there is an element aside from carbon inside the ring
difference between U and T
uracil does not have a CH3 group
bond of nitrogenous base to the anomeric carbon
beta-glycosidic linkage
sugar and base combined are called
nucleoside
adenine + sugar base
adenosine
2-deoxyadenosine
what carbon is the phosphate added
5’
is involved in the regulation of glycogen, sugar, and lipid metabolism.
cyclic adenosine monophosphate
second messenger molecule released in signal transduction
cylic adenosine monophosphate
in nucleic acids, the monomers are connected by:
phosphate esters
approximate frequency of this base in human DNA is about 30% (2)
adenine (A)
thymine (T)
approximate frequency of this base in human DNA is about 20% (2)
cytosine (C)
guanine (G)
DNA is stored by coiling around proteins called
histones
coils of DNA around histones undergo what process to save more space
supercoiling
one long supercoiled DNA molecules with the histones are called
chromosome
all the DNA material in the nucleus of the cell is collectively called
chromatin
the basic repeating subunit of chromatin packaged inside the cell’s nucleus.
nucleosome
3 major differences between RNA and DNA
RNA contains ribose as the sugar while DNA contains 2-deoxyribose
RNA uses uracil (U) while DNA uses thymine (T).
RNA is single-stranded while DNA is double-stranded
is produced by transcribing (copying) from DNA, and unlike the double strand of DNA, it is usually single-stranded.
RNA
biological functions of RNA
mRNA
rRNA
tRNA
enzyme
RNA that carry information
mRNA (messenger RNA)
RNA that is part of the ribosome
rRNA (ribosomal RNA)
RNA that carry amino acids in the form of
tRNA (transporter RNA)
RNA function aside from mRNA, rRNA, and tRNA
act as an enzyme
regulate gene expression
Nucleic acids are specialized for
storage and transmission of genetic information
important in cell division and reproduction
where DNA is stored in eukaryotic cells
nucleus
two main biological functions of DNA
contains the genetic material responsible for inheritance
directs and regulates protein synthesis.
transmission of stored information from mother to daughter cells
vertical gene transfer
duplicate copy of DNA during cell division
DNA replication
in what kind of cells DNA is linear-stranded double helix
eukaryotic cell
a linear-stranded double helix wrapped around histones
DNA
proteins that act as spools around which DNA is wound
histones
DNA is a linear-stranded double helix wrapped around histones to form a
nucleosome
importance of RNA
protein synthesis
is a linear molecule that carries a copy of the gene to be expressed from the nucleus
Messenger RNA
group of three bases
codon
how many codon codes for an amino acid
3 groups
short, unstable, single-stranded RNA corresponding to a gene encoded within DNA
mRNA
intermediary between DNA and protein, directs the synthesis of the protein it encodes
what kind of RNA
mRNA
single strand of RNA which folds due to base pairing to form an unusual shape of cloverleaf
transfer RNA (tRNA)
shape of tRNA
cloverleaf-like
has a triplet anti-codon site and attachment site for specific amino acid
transfer RNA
how many nucleotides does tRNA have
70-90
short, stable RNA with extensive intermolecular base pairing; contains an amino acid binding site and mRNA binding site
tRNA
carries the correct amino acid to the site of protein synthesis in the ribosome
tRNA
form the ribosome which is the structure where protein synthesis takes place
rRNA
longer, stable RNA molecules making up of the 60% of the ribosomes mass
rRNA
rRNA makes up what percent of the ribosome’s mass
60 percent
ensures alignment of mRNA, tRNA, and ribosome during protein synthesis
rRNA
catalyzes peptide bond formation between amino acids
rRNA
is an important process in cells, because without it, a cell is not able to accommodate the large amount of cell stored inside
DNA packaging
contains a well-defined nucleus
eukaryote
in prokaryotes, the chromosome lies in the cytoplasm in an area called
nucleoid
what cells does DNA and RNA synthesis occur in separate compartment from protein synthesis
euakryotic cells
cells wherein DNA and protein synthesis occur in the same compartment
prokaryotic cells
size of genome of E. coli
4.6 million base pairs
DNA is twisted by what is known as
supercoiling
means DNa is either under-wound or over-wound
supercoiling
less than one turn of the helix per 10 base pairs
under-wound
more than 1 turn per 10 base pairs
over-wound
enzyme helping in maintaining the supercoiled structure by relieving the strain brought about the coiling process
DNA gyrase
has chromosomes that consist of linear DNa molecule, employing a different type of packing strategy to fit their DNA inside the nucleus
Eukaryotes
at the most basic level, DNA is wrapped around proteins known as
histones
are evolutionarily conserved proteins that are rich in basic amino acids and form an octamer
histomes
DNA is charged (+/-)
negatiive
reason why DNA is negatively charged
phoshpate groups
at physiological pH, the histones are charged
positively
links one nucleosome to another
linker DNA
known as the beads on a string structure
nucleosomes
diameter of the structure of nucleosome
30 nm
what phase of cell division does the chromosomes are the most compact (approximately 700nm)
metaphase
chromosomes in metaphase are in association with what kind of proteins
scaffold proteins
what fiber does nucleosomes are coiled into
chromatin fibe
DNA is found in which organelles in eukaryotes
nucleus
chloroplast
mitochondria
difference between DNA in eukaryotes and prokaryotes
E - enclosed in a membrane envelope
P - is in the cytoplasm
forces of attraction that hold the double stranded DNA together
hydrogen bonds
between adenine and thymine, there are __ hydrogen bonds
two
between guanine and cytosine, there are ___ hydrogen bonds
three
DNA fragments with more G and C are more/less stable
more
more stable DNA strands are
less likely to separate
nitrogenous base is attached to what carbon
1’ of the ribose
phosphate group is attached to what carbon
5’ of the ribose
when a polynucleotide is formed, what carbon of the incoming nucleotide is attached to the hydroxyl group at the end of the growing chain
5’ phosphate of incoming nucleotide attaches to the 3’ hydroxyl group of the end of the growing chain
never leave the nucleus but instead use intermediary to communicate with the rest of the cell
DNA
intermediary used by DNA to communicate with the rest of the cell
mRNA
enters the nucleus and attaches itself to one of the DNA strands when proteins are needed to be made
mRNA
being complementary, the sequence of nitrogen bases of the RNA is ___ to that of the DNA
opposite
sequence of nitrogen bases of RNA opposite that of the DNA is called what process
transcription
mRNa then carries the code out of the nucleus to organelles called what
ribosomes
the synthesis of DNA or RNA always assumes what direction
5’ to 3’ direction
enzyme responsible for the synthesis of DNA is called
DNA polymerase
compounds that are used by DNA polymerase to synthesize DNA (4)
ATP
GTP
CTP
TTP
nucleotides undergo what process to activate
phosphorylation
enzyme responsible for the synthesis of RNA is called
RNA polymerase
compounds used by RNA polymerase to synthesize RNA are (4)
ATP
GTP
CTP
UTP
one the mRNa has reached the ribosomes, the ribosomes do not read the instructions directly, instead another type of RNA called is needed to translate the information from mRNA to usable form
tRNA
the amino acids first attach themsleves to specific tRNAs through what enzyme
tRNA synthethase
complex that attaches to the mRNA through the action of RNA synthethase
tRNA-amino acid
tRNA-amino acid attaches to the mRNA using what end
anti-codon end
is part of tRNA that contains bases that are complementary to the codon in mRNA
anti-codon
reads the sequence of three bases in the mRNA
ribosome
each possible three letter arrangement of codons come from (4)
A
C
U
G
correspondence of these instructions and amino acids is known as the
genetic code
start codon
AUG (methionine)
stop codon (3)
UAA
UAG
UGA
the portion of the mRNA having 5’ AGG UUC AGC 3’ when translated will have the peptide sequence of
arg-phe-ser
acts like a giant clamp, holding all the players in position, and facilitating both the pairing of bases between the messenger and transfer RNAs, and the chemical bonding between amino acids
ribosome
special subunits of ribosomes
ribosomal RNAs
do not carry instructions for making specific proteins but are instead an integral part of the ribosome machinery that used to make proteins from mRNAs
rRNas
making of proteins by reading instructions in mRNA is generally known as
translation
enzyme responsible for joining amino acids together during translation is called
peptidyl transferase
peptidyl transferase reads this RNA from 5’ to 3’ direction
mRNA
newly synthesized peptide chain grows from what terminal to another
N-terminal to C-terminal
cell division phase where eukaryotic chromosomes have two distinct regions that can be distinguished by staining
interphase
tightly packed region in eukaryotic regions with two distinct regions
heterochromatin
less dense region, lightly packed form of chromatin (DNA, RNA, and protein) that is enriched in genes, and is often (but not always) under active transcription.
euchromatin
usually contains genes that are not expressed and is found in the regions of the centromere and telomere
heterochromatin
usually contains genes that are transcribed, with DNa packaged around nucleosomes but not further compacted
euchromatin
the process where DNA is copied into another DNA is called
replication
when DNa is copied into an RNA the process called
transcription
when the information in the mRNA is used to direct protein synthesis, the process is called
translation
some of these can have the ability to synthesize DNA from RNA
viruses
viruses synthesizing DNA from RNA is a process called
reverse transcription
