Lecture 1 Flashcards
Flow of Genetic Information
DNA (Replicates) ==> (transcription) RNA ==> (translation) Protein
What are the Four nucleotides that make up DNA?
A (Adenine) = T (Thymine)
C (Cytosine) = G (Guanine)
How many nucleotides to make 1 Amino Acid
3
- Where is the information stored?
2. What’s the rule for base pairing?
- Information content is in the sequence of
bases along a DNA molecule - each strand of the double
helix has all the information needed to recreate the
other strand
Why do individuals have different phynotypes?
Genetic variation — differences in the base
sequence between different individuals
When does DNA replication occur?
Before cell division
Where are the new subunits added to ?
they are added to the 3’ end (5’ ==> 3’)
How accurate is DNA replication?
10^-9 mistake frequency
What are the three mechanism that produce remarkable replication accuracy?
- DNA polymerase base selection.
- DNA replication proofreading.
- Mismatch repair.
How does DNA polymerase work?
Selects base polymerized by complementarity
What’s the error rate of DNA polymerase?
Base selection 10^-4
Proofreading 10^-4
mismatch repair 10^-1
total = 10^-9
How does mismatch repair work?
Mismatch repair system recognizes mismatched base pairs and replaces
is matched base on newly made strand with correct
base
what are genes?
Segments along the chromosomal DNA that code for some function
What is replication?
DNA replicates
What is transcription?
“copy” gene into RNA to make a protein
Where are promoters? where are terminators located?
???????
What’s the difference between DNA and RNA
RNA not coiled, single strained, has Uracil (U) instead of Thymine (T)
Which way does the RNA move?
RNA moves 3’ to 5’
which way does the RNA polymerase synthesize?
RNA synthesizes 5’ to 3’, adds to 3’ end.
What are introns? what are exons? What are UTRS? what is ORF?
Introns are parts of DNA not coding.
Exons are coding
UTRs are untranslated regions
ORFs are open reading frame
which is the mRNA read?
From 5’ to 3’
what are long vertical lines? Short?
Long = Stop codons Short = possible start codons
one genes codes for how many proteins?
1 gene codes for one protein.
