module 6 nucleic acids Flashcards
what are the 2 most common nucleic acids
DNA: deoxyribnucleic acid
RNA: ribonucleic acid
What does DNA store
store and transmit genetic information to determine amino acid sequence of the primary protein structure
what is the primary function of RNA
make proteins
What are 3 types of RNA
messenger, transport, ribosomal
Where does RNA exist in the cell
multiple places including nucleus
what type of structures are RNA and DNA and what are they built from
polymer and macromolecule
built from nucleotides
what is needed to make a nucleotide
a base, a monosaccharide sugar, and phosphoric acid
what are the 2 bases found in DNA and RNA
purine and pyridine
Which are the purine bases
adenine and guanine
Which are the pyrimidine bases
cytosine, uracil, thymine
why are the bases considered to be hetercylic
there is nitrogen in the ring- an atom other than carbon
which pyrimidine is only found in DNA and which is only in RNA
DNA: thymine
RNA: Uracil
How is the structure of thymine different compared to uracil
there is an extra methyl group on thymine
in general both DNA and RNA have ? purines and ? pyrimidines
2, 2
Which sugar is in RNA
Which sugar is in DNA
RNA: D-ribose
DNA: 2-deoxy-D-ribose
What is the difference between the sugars of DNA and RNA
there is an -H on carbon 2 of 2-deoxy-D-ribose verses and OH in D-ribose
what does a nucleoside consist of
a base, purine or pyrimidine covalently bonded to either ribose or 2-deoxyribose
where does bonding occur to form a nucleoside
carbon 1- the anomeric carbon- based off the N atom as well
what is an example of a formation of nucleoside
guanine + ribose= guanosine
what reaction does guanine and ribose undergo to form guanosine
condensation
what forms the nucleotide
a nucleoside bonded with phosphoric acid
when do nucleic acids form
nucleotides polymerize into chains which form into DNA or RNA
what forms the primary structure for DNA
RNA?
DNA:: covalent bonding of nucleotide monomers- form backbone: deoxyribose and phosphate alternate
RNA: ribose and phosphate form the backbone
How are nucleotides written schematically
5’ to 3’- gives primary structure
left to right
what is an oligonucleotide
nucleotide chain less than 50 nucleotides
what is the secondary structure of nucleic acids
any stable structure used by some or all nucleotides
what is the tertiary structure of nucleic acids
massive and folding
How is the secondary structure of nucleic acids best described
As a double helix
who determined the double helix and who was key in understanding structures
James Watson and Francis Crick in 1953
Erwin Chargaff
What are 3 main conclusions regarding nucleic acids
- base genetic composition of DNA differs between species
- DNA isolated from tissues or parts of the organism is the same
- In DNA( A and T are equal, G and C are equal)
Describe the double helix structure
2 polynucleictide chains run in opposite direction- held by hydrogen bonds
bonding between A and T and G and C
Show a strand written from 5’-3’ and its complementary strand
5’-GCCTTAGCAAT-3’
3’-CGGAATCGTTA-5’
Which is the most common form of DNA
B-form
what are the other 2 forms of DNA
A and Z is different as it has a l-handed turn
what is the primary function of DNA no matter the form
to store genetic information that contains protein sequences
What is a gene
protein sequence stored in DNA
what is a codon
3 adjacent nucleotides that encodes an amino acid of a protein
in a gene how many nucleotides are needed to encode for a protein
150-2000
in a 100 amino acid protein- how many nucleotides needed to encode it
300
codon is 3x
what are 3 types of RNA
messenger(mRNA)
transfer(tRNA)
ribosomal(rRNA)
What is the job of mRNA
carries genetic information stored in DNA to ribosomes
What is the structure of mRNA
single strand and contains information to create specific proteins and size is revelant to the protein
What does Adenine bond with to create a pair in RNA
Uracil
what happens to mRNA after protein is made
it is degraded
What is tRNA
transfer RNA used to transport amino acids to ribosome for protein synthesis
How many nucleotides are in a tRNA chain
70-90- smaller than other RNA chains
How is tRNA bonded
each chain is covalently bonded to an amino acid that it transports
Does tRNA fold on itself
yes- as it folds to form hydrogen bonding
nucleotides interact with the hydrogen bonding and forms the secondary structure
What is rRNA
RNA that is used to create proteins
what makes up a ribosome
35% protein
65% RNA
How large is rRNA
1 million dalton
much larger than tRNA
what is the structure of rRNA similar to
proteins
Where do you see the rRNA
thick lines of the double helix
What can GTP be used for
energy production in some cases
Guanosine triphosphate
What is an example of GTP being used
in Citric acid cycle to store energy
How does GTP help the citric acid cycle
helps ADP to become ATP by transferring a phosphate group
what is another name for citric acid cycle
energy harvesting pathway
what is cMAP and what is its role
second messenger
communicates cell to actively export glucose- especially after liver cells bind with adrenaline
cAMP can bind to?
proteins-but not the same
“structure determines function”
its structure is different compared to AMP
what is the final function of nucleotides discussed in module and provide an example
the nucleotide as a coenzyme
FAD- flavin adenine nucleotide
what is the function of FAD
move hydrogen atoms from 1 molecule to another in enzymatic-catalyzed reactions
What is the difference between a nucleoside and nucleotide?
A nucleoside is formed from the covalent bonding of a base, purine or pyrimidine, to either ribose or 2-deoxyribose. Nucleotides are built from a nitrogen-containing organic base, a monosaccharide, and phosphate.
What characteristic makes purines and pyrimidine heterocyclic?
Each has a ring with nitrogen in the ring instead of all carbon atoms in the ring.
What is the difference between thymine and uracil?
There are a couple differences between thymine and uracil. Thymine is used in DNA and bonds only to adenine in DNA. It also has an extra methyl group. Uracil is only found in RNA and does not have the extra methyl group. It will also bind to adenine in a RNA structure.
From the course and module information, where in a eukaryotic or prokaryotic cell, is the DNA located? How about the RNA?
DNA is located in the nucleus of a eukaryotic cell or the nucleoid of a prokaryotic cell. RNA is found in the nucleus, on the ribosome, and in other parts of the cell.
Which DNA and RNA bases contain a carbonyl group?
Guanine, cytosine, thymine, and uracil all contain C=O group attached to the rings. Adenine is the only base that does not.
What constitutes the backbone of DNA?
In DNA, this consists of the alternating deoxyribose and phosphate groups linked together through covalent bonds (Figure 6.6).
How many hydrogen bonds form between A and T?
Two hydrogen bonds are formed between these two bases. G and C form three H-bonds.
Which nucleic acid is single-stranded?
RNA. RNA forms single strands. Particularly this was noted in this module for tRNA. DNA forms a double helix.
What interactions stabilize the DNA double helix?
Hydrogen bonds stabilize the helix. Each AT pair and form two hydrogen bonds, and each GC pair forms three hydrogens that stabilize the helix, permitting it to maintain this shape.
What type of RNA has a sequence that is complementary to DNA?
mRNA is complementary so that it can transmit the information to the ribosome.
Which has the largest molecular weight chains: mRNA, tRNA, or rRNA?
rRNA. These molecules make up ribosomes.
What structural forms of DNA have a right-handed helix? Which form has a left-handed helix?
The A- and B-forms are right-handed, while the Z-form is left-handed.
What function does cAMP perform in cells?
cAMP is a communication molecule in cellular signaling. It acts as a secondary messenger.
