Hershey and Chase Experiment
Used radioactive material to label DNA and protein; infected bacteria passed on DNA; helped prove that DNA is genetic material not proteins; DNA contains phosphorus, whole protein contains sulfur
Semi-Conservative Replication
Method of DNA replication in which parental strands separate, act as templates, and produce molecules of DNA with one parental DNA strand and one new DNA strand
Base Pair Rules
DNA: A-T, C-G
RNA:A-U, C-G
Direction of Synthesis
From 5' to 3'
DNA Polymerase
Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule
RNA Polymerase
Enzyme that links together the growing chain of RNA nucleotides during transcription using a DNA strand as a template
Enzymes Involved in DNA Replication
Helicase: splits and unwinds the 2-stranded DNA molecule
DNA Gyrase: relieves strain that comes from cutting, winding, and rejoining DNA strands
DNA Polymerase I: digests RNA primer and replaces it with DNA
DNA Polymerase II: extends RNA primer with short
Restriction Enzymes
Enzyme that cuts DNA at a specific sequence of nucleotides
Plasmid
A small, circular section of extra DNA that confers one or more traits to a bacterium and can be reproduced separately from the main bacterial genetic code.
Reading a gel electrophoresis
The stained DNA segments, when a current is applied, move toward the positive pole of the gel. The smallest fragments move the quickest, so they will move the farthest
Transcription
The first step of gene expression; takes place in the nucleus and is carried out by the enzyme RNA Polymerase (rewrites the DNA into a primary transcript using a single template strand of DNA)
Promoter
A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing RNA.
Terminator
A special sequence of nucleotides in DNA that marks the end of a gene. It signals RNA polymerase to release the newly made RNA molecule, which then departs from the gene
mRNA
Codon: three nucleotides that correspond to a single AA
Splicing: the removal of introns and joining of Exon's in eukaryotic mRNA
Modifying: changing of DNA into RNA so that the strand can leave the nucleus and be translated
Cap: protects from degradation
Splicing
The process of removing introns and reconnecting exons in a pre-mRNA
tRNA anticodon
A sequence of three adjacent nucleotides in tRNA designating a specific amino acid that binds to a corresponding codon in mRNA during protein synthesis
How to read a Codon Chart
1. Located the first letter of your codon using the left side of table
2. Move to the second letter using the the first column
3. Find the third using the letters on the right side of the table
4. Find the AA that is in the right columns and rows of the c
Point Mutation
Gene mutation in which a single base pair in DNA has been changed
Frameshift Mutation
Mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide
What controls a repressible operon?
A small regulatory molecule such as lactose or tryptophan
Lactose operon
Regulates the production of proteins involved in metabolism of lactose
TRP operon
Tryptophan binds to the repressor protein and enables it to repress gene transcription.
Methylated-DNA
An epigenetic mechanism used by cells to control gene expression. Is the addition of a methyl (CH3) group to the DNA stand, often to the fifth carbon atom of a cytosine ring