1.01 - The Central Dogma Flashcards
(21 cards)
What are the three elements to DNA?
Phosphate Backbone
Deoxyribose sugar
Nitrogenous Bases
What are the two purine bases?
Adenine
Guanine
What are the three pyrimidine bases?
Cytosine
Thymine
Uracil
Name the complementary base pairs
Adenine & Thymine (Uracil)
Guanine & Cytosine
What is transcription and where does it occur?
The conversion of DNA to RNA and it occurs in the nucleus
What is translation and where does it occur?
The use of RNA as a template to produce protein and it occurs in the cytoplasm
Contrast and Compare the structures of DNA and RNA
DNA: Contains deoxyribose (lacks an oxygen atom) ATGC Double stranded Mostly helical RNA: Contains ribose sugar AUGC Mostly single stranded Complex array of secondary structures
What is a codon?
Codons are 3 nucleotides in a row which code for an amino acid
What is amino acid redundancy?
Only 20 amino acids exist for a possible 64 nucleotide combinations in the codon.
What is a gene?
A portion of the genetic code which codes for a protein or functional RNA
Compare and contrast the coding and non-coding strands of DNA
Non-coding: Template (used to make the mRNA) Anti-sense Non-transcribed strand Coding: Non-template Sense Transcribed strand
What are the three stages of Transcription?
Initiation
Elongation
Termination
Describe the Initiation phase of Transcription
RNA polymerase binds to DNA promotor region (closed complex)
RNA polymerase unwinds the section of DNA (open complex)
Catalyses the linkage of initial pre-mRNA
Describe the Elongation phase of Transcription
RNA polymerase moves 3’ to 5’ along the template strand of DNA. Produces pre-mRNA
Describe the Termination phase of Transcription
RNA polymerase releases the completed pre-mRNA
What is an exon? And what happens to it during RNA processing?
It is the coding region of RNA and exons are spliced together during RNA processing
What is an intron? And what happens to it during RNA processing?
It is the non-coding region or RNA and introns are removed and degraded during RNA processing
What is the spliceosome and what do they do?
They are a group of small nuclear ribonucleases (snRNPs), they post modify the pre-RNA to mRNA.
What is mRNA?
The template strand for translation to produce a protein
What is the ribosome made up of?
ribosomal RNA (rRNA) and proteins units. Has two subunits: The small (40S) and the large (60S)
Describe the steps in translation
The mRNA will leave the nucleus. Ribosome binds the mRNA in the cytoplasm. Anticodon of tRNA will bind to the codon on mRNA and add its attached amino acid to the growing peptide chain
