DNA Exam Flashcards
(21 cards)
Which direction does DNA replication occur
5-3 BC DNA polymers needs a starting block to begin
How many bases make a cordon?
A codon is 3 nucleotides
Base pair rules?
Each pair bonds with just one type of base
Difference between a purine and a pyrimidne
Purine has a 2 ring structure, A&G. Pyrimidine has one ring, T/U&C
Difference between leading and lagging strand
Lagging: reply strand continually grows w/o gaps, 5>3, a single primer is needed.
Leading: okazaki fragments & growth is continued, DNA legate is requires,
Diff types of mutations
Missense: code for incorrect AA
Nonsense: changes AA>stop codon
Silent: code for the same AA
Griffiths expiriment
Translation: substance from dead bacteria cells taken into non virulent part. Then gets transformed and gets passed to future Gen’s.
Heresy-Chase
Virus are with DNA covered in protein. Viruses infect bacteria = bacteria that even.
What is a primer
A strand of nuclei acid that serves as a starting point for DNA synthesis
What is telomerase
Its bunches of DNA at the end of chromosomes that prevent deterioration of chromosomes. They determine how long people live
What is happening at E P A sites of ribosomes?
P- tRNA carries the growing polypeptide chain
A- tRNA with the next amino acid
E- discharged tRNAs exit
Diff between exon and intron
Introns stay in the nucleus and keep the dna safe. Exons leave the nucleus to be made into a protein
What type of rna is most abundant in your cells
rRNA because it’s responsible for coding and producing the proteins in cells
What type of chemical bond is found between bases
Hydrogen bonds
What occurs at translation
- Initiation: starts w/ Rna polymerase binds to promoter
- Elongation: nucleotides added to rna chain. Strand of dna serves as dna for dna synthesis
- Termination: ran synthesis goes along DNA until signaled to stop
What occurs at transcription
Initation: involves a promoter region that has a TATA box that’s a binding site for RNA polymerase
Elongation: RNA polymerase adds complementary nucleotides to rhe 3’ of growing strand
Termination: RNA polymerase reaches a terminator sequence. mRNA must be modified before it can leave the nucleus
Role of regulatory gene
Produces mRNA that makes a lac protein that binds to the operator
Role of the operator in an operon
Controls transcription
Role of the repressor in an operon
In the absence of lactase, it binds to the operator and prevents RNA polymerase from transcribing
Role of promoter in an operon
Binding site for RNA polymerase
Difference between transcription and translation
In transcription, RNA is synthesized from DNA.
In translation, proteins or polypeptides is synthesized from RNA.
