Unit 4 day 2 Flashcards
The larger size and complex packaging of eukaryotic chromosomes means they must be replicated from what?
Multiple origins.
Synthesizing the ends of the chromosomes is difficult because of what?
The lack of a primer.
With each round of DNA replication the linear eukaryotic chromosome becomes what?
Shorter
What are mutations?
It is mistakes during DNA replication can lead to changes in the DNA sequence and other DNA damage.
What are mutagens?
It is DNA that can also be damaged by chemical or physical agents
What is specific DNA repair?
It targets a particular type of DNA damage
What is an example of specific DNA repair?
Thymine dimers
What is non-specific DNA repair?
It can repair many different kinds of damage
What is an example of non-specific DNA repair?
Excision repair
What is central dogma of molecular biology?
It states that information flows in one direction, from DNA to RNA to protein
What is transcription?
It is the flow of information from DNA to RNA
What is translation?
It is the flow of information from RNA to protein
What do we know today about the nature of genes?
One gene- one polypeptide hypothesis
What are the main 4 nucleotides?
A, T, G, C
Crick and Brenner determined that DNA is read in sets of what?
3 nucleotides for each amino acid
What is codon?
A set of 3 nucleotides specifying a certain amino acid
What is a reading frame?
The series of nucleotides that will produce the “right” protein when read in sets of 3.
What are the stop codons?
UUA, UGA, and UAG
What is the start codons?
AUG
What is degenerate?
The remainder of the code
What does degenerate mean?
Some amino acids are specified by more than one codon
What is wobble pairing?
It is the last base is the variable.
What does template DNA strand do?
Make RNA
What does coding DNA strand do?
It is the complementary to the template strand
What is RNA polymerase?
It is an enzyme that synthesized the primary RNA transcript using the template DNA strand
What is RNA transcript?
It has the same nucleotide sequence as the coding for DNA strand.
What is initiation regarding transcription?
RNA polymerase identifies a specific starting DNA sequence.
What is elongation regarding transcription?
Ribonucleotides are added to the 3’ end of the new RNA
What is termination regarding transcription?
RNA polymerase stops when it encounters a terminating DNA sequence.
How many types RNA are required for gene expression?
6 types
What does mRNA do?
It carries the information from DNA that encodes proteins
What does rRNA do?
It is a structural component of the ribosome
What does tRNA do?
It carries AA to the ribosome from translation
What is mRNA?
It is messenger RNA
What is rRNA?
It is ribosomal RNA
What is tRNA?
It is transfer RNA
What is the sigma factor?
It is what is required for transcription initiation
Does translation or transcription come first?
Transcription
