exam 3- dna Flashcards
(55 cards)
Where is DNA stored?
Cell nucleus
What are the parts of a nucleotide?
1, phosphate group
2. Five carbon sugar
3. Nitrogenous base
What’s the construction of a DNA molecule?
Phosphate attached to 5’ carbon of top sugar and 3’ carbon of lower sugar
What’s an example of a purine?
Adenine and guanine
What’s an example of a pyridine?
Cytosine, thymine, and uracil
How do nitrogenous bases bind to one another?
- Adenine
- cytosine pairs with guanine
What’s the difference between DNA and RNA molecules?
RNA contains the sugar ribose, while DNA contains sugar deoxyribose
Central dogma of information flow?
DNA → RNA → protein
What is a gene?
The basic physical and functional unit of heredity
Transcription
The process of making an RNA copy of a genes DNA sequence
Transcription initiation
The phase during which the RNA chain are synthesized
Transcription elongation
The stage when the RNA strand gets longer, thanks to the addition of new nucleotides
transcription termination
polymerase releases the DNA template and the nascent RNA
Where does transcription happen in the cell?
in the cytoplasm
-> in prokaryotes and in the nucleus of eukaryotes
What is the difference between the template strand and the non-template strand?
the template strand can duplicate itself during mRNA synthesis
the non-template strand is the same as the new RNA molecule.
What is complementary base pairing?
the sequence of one DNA strand
determines the sequence of the
other
mRNA cap
structure added to the 5′ end of mRNA
mRNA poly- A tail
structure added to the 3’ end
of mRNA
exons
the sequences that specify amino
acids
introns
sequences in genes that are not used
for producing a protein
Where does the mRNA go once it has been modified?
to the cytoplasm, where the ribosomes are located
What is translation?
the process by which a cell makes proteins using the genetic information carried in mRNA
Ribosomes bind to mRNA and facilitate the production of an amino acid chain
-> occurs in the cytoplasm
what is a codon and what does it code for?
three nucleotides that encodes one amino acid. (DNA, mRNA, polypeptide)
The genetic code shows which mRNA
codons correspond to which amino acids
what is tRNA (transfer RNA)?
“connectors” that carry each amino acid to the correct spot along the mRNA molecule.
-> “translates” the genetic code
