Finals: Nucleic acid Flashcards
an unbranched polymer in which the
monomer units are nucleotides.
Nucleic Acids
functions of nucleic acids
Provides information on how to make new cells
location of nucleic acids
Initially found in cell nuclei and are acidic in nature; hence the name nucleic acid
who discovered nucleic acids
Friedrich Miescher in 1869 while studying the nuclei of white blood cells.
Type of nucleic acid:
- It is found within the cell nucleus
- Stores and transfers genetic
information - Passes from existing cells to
new cells during cell division
Deoxyribonucleic acid (DNA)
Type of nucleic acid:
- Occurs in all parts of a cell
- Primary function is the
synthesis of proteins
Ribonucleic Acid (RNA)
what are the components of a nucleotide
Pentose sugar, Heterocyclic base, Phosphate group (PO43-)
a three-subunit molecule in which a pentose sugar is bonded to both a phosphate group and a nitrogen-containing heterocyclic base.
Nucleotide
what are the components of a nucleotide
Pentose sugar §Heterocyclic base §Phosphate group (PO43-)
all of these are covalently bonded together
The structural difference between ribose and pentose 2′ - deoxyribose occurs at
carbon 2′
Pentose sugar: present in ribose
-OH Group
pentose sugar:
present in 2’-deoxyribose
-H atom
pentose sugar: present in RNA
Ribose
pentose sugar:
present in DNA
2’-Deoxyribose
what are the 5 total nitrogen containing heterocylic bases?
3 pyrimidine deriatives - thyme (T), Cytosine (C), Uracil (U)
What are the 2 purine derivatives?
Adenine (A) and Guanine (G)
Adenine, Guanine, and Cytosine are found in both
DNA
and RNA
found only in RNA
uracil
found only in DNA
Thymine
The third component of a nucleotide
phosphate
Derived from phosphoric acid (H3PO4)
phosphate
it loses how what and how many in result of formation of a ?
2 hydrogen atoms, hydrogen phosphate ion (HPO 4^-2)
the sequence in which nucleotides are linked together in a nucleic acid.
Primary nucleic acid structure
nucleotide directionality:
5’ end
a free phosphate group attached
to the 5’ carbon atom
nucleotide directionality: 3’ end
a free hydroxyl group attached to the 3’ carbon
The name of the polynucleotide is named from:
5’ -> 3’ end
ü 5’ C-A-T-G 3’
- Primary structure depends on the
sequence of bases present
The alternating sugar-phosphate chain in a nucleic acid structure is often called the
nucleic acid backbone
this is called the nucleic acid backbone
alternating sugar-phosphate chain in a nucleic acid structure
For DNA molecules, the backbone consists of alternating
phosphate and deoxyribose sugar units;
For RNA molecules, the backbone consists of alternating
phosphate and ribose sugar units
a nucleotide polymer
dna and rna
Contains 2-deoxyribose
dna
does not contain in uracil
dna
resistant to base hydrolysis
dna
contains ribose
rna
does not contain thymine
rna
sensitive to base hydrolysis
rna
how do u specify a primary structure for a nucleic acid?
done by listing nucleotide base components in sequential order starting with the base at the 5’ end of the nucleotide strand.
Double helix: In addition to primary structures, nucleic acids also have
secondary and tertiary structures
Amounts of ______ present in DNA molecules helped determine the three- dimensional structure of the DNA molecules
A,T,G, and C
Human DNA contains:
30% adenine
30% thymine
20% guanine
20% cytosine
Chargaff’s Rule:
of A = # of T
o # of G = # of C
A pyrimidine is always paired with a purine
Base pairing
Fits inside the DNA double strand
It is the most favored in A–T
and G–C pairs
hydrogen bonding
G-C pairs are held together by
3 hydrogen bonds
a pair termed complementary
A–T and G–C pairing
are held together by 3 hydrogen bonds
G-C Pairs
are held together by 2 hydrogen bonds
A-T pairs
A-T pairs are held together by
2 hydrogen bonds
Which of the following pairs is easier to break?
A-T Pairs
what happens in DNA sequence
- Bases on each strand extend inwardly toward each other
- They are connected by hydrogen bonds
- They run in opposite directions
Two polynucleotide strands are coiled around each other in a spiral
DNA Sequence
The total, unique DNA content of an organism is called its
genome
DNA carries the genetic information of the
blueprint
RNA carries the genetic information from DNA for the
synthesis of proteins necessary for cellular function.
DNA molecules aggregate to form
chromosomes where
the different genes are allocated.
produce enough copies for itself and the production of a daughter cell during mitosis
Replication
Important enzymes in DNA
replication include:
- DNA Helicase
- DNA Polymerase
- DNA Ligase
responsible
for unwinding the DNA
double helix
DNA Helicase
RNA is formed by _____ in order to carry information from DNA for protein synthesis.
transcription
This process protects the DNA from mutations.
Transcription
Important enzyme in this transcription process is
RNA polymerase
The processing of information stored in DNA into biomolecules that dictate biochemical processes in the cell involve three steps:
Replication, Transcription, Translation
Replication, Transcription, Translation
are steps reffered to the
central dogma of molecular biology
Changes in DNA structure will affect the structure of proteins produced during translation
Mutations
Alterations in the structure of DNA are called
mutation
is a natural process observed in organisms. Mutations
in the molecular level bring about the evolution of organisms
through the passage of time
mutations
Mutations can arise from exposure to physical or chemical agents that cause changes in DNA structure called
mutagens
substitution of one nucleotide to another
Point Mutation
removal of one or more nucleotides
Deletion Mutation
one or more nucleotides are added into the sequence
Insertion Mutation
change in the DNA structure that does not change the amino acid coded
Silent Mutation
