Molecular Geneitcs Flashcards
When does DNA replication occur? And in what fashion does it replicate?
Replication occurs during interphase, and replicates in a semi-conservative fashion
What is the name of the nonsense nucleotides sequences at the end of chromosomes? And where do they come from?
Teleomeres and they come from the enzyme telemorase
What are the 3 types of RNA? State their function
mRNA-made during transcription, carries the DNA code to the ribosome where the message is translated
tRNA-Carries amino acids to the mRNA at the ribosome during translation
rRNA-makes up part of the ribosome, site of protein production
What are the three steps that create protein from DNA?
Transcription-begins with RNA polymerase binds to the DNA strand, then it pries the strands apart and adds nucleotides to the growing end of the strand, when it reaches a stop codon it terminates the process.
RNA processing-after transcription the transcript is spliced by snRNPs they remove the non-coding regions(introns) and keep the exons, then the transcript is stuck back together.
Translation-converting the mRNA into a amino acid, tRNA molecules carries amino acids to the ribosome according to base parring rules
What is the start codon? And what are the three end codons?
Start codon-AUG
End codon-UAA,UAG,UGA
What are the two types of operons and what do they do?
Lac operon-always turned off until needed to be on
Repressible operon-always turned on until needed to be off
What are the parts of a operon?
Promoter-on switch, RNA polymerase must bind to a promoter on the DNA before transcription
Operator-binding site for the repressor, which turns on the lac operon
TATA box-helps RNA bind to the promoter
There are three types of gene mutations they are
Point-one nucleotide converts to another
Deletion-is the loss of one letter causing frameshift
Insertion-is the addition of one letter causing frameshift
What is recombinant DNA, and which branch of science uses it?
Taking DNA from 2 sources and combining them, genetic engineering uses this
What is the function of restriction enzymes
They cut DNA at specific restriction sites to, referred to as molecular scissors, the result is the creation of cut up DNA called restriction fragments
What is gel electrophoresis
The separating of large molecules of DNA based from their rate of movement as they flow through an agarose gel in a electric field, the smaller the faster they run through the gel
What is polymerase chain reaction PCR
Automated technique in which a piece of DNA can be rapidly copied
