October 21 Flashcards
Operon
Cluster of genes under the control of a single regulatory signal, can be shut down to save resources
Unit of transcription
Area on a chromosome containing the coding sequence and regulatory sequences that direct and regulate synthesis of that protein
Single RNA molecule
Promotor, RNA-coding sequence, terminator
mRNA
short half-life before being degraded by ribonucleases, rapid turnover allows cell to quickly adapt
Polycistronic mRNA
Codes for a group of cotranscribed genes
Genetic Code
Correspondence between the nucleic acid template and the amino acid sequence of the polypeptide product
Codon
triplet of 3 bases encoding a specific amino acid
Anticodon
Found on tRNA, recognizes codon on mRNA
Wobble
base pairing is more flexible for the third base of a codon
Stop codon
nonsense codon, stops translation
UAA, UAG, UGA
Start codon
AUG
codes for N-formylmethionine
Shine-Dalgarno Sequence
Upstream sequence on mRNA, ensures proper reading frame
Open-reading Frame
Begins with AUG followed by codons and then a stop codon in the same reading frame as the start codon
Archean Chromosomes
- resemble bacteria
- circular
- 500-100s of genes
- Bidirectional replication
How do Archaean’s resemble bacteria?
Chromosomes do not have introns
Single-celled divide by binary fusion
No membrane bound nucleus or organelles
Coupled transcription and translation
Single circular chromosomes
Shine-Dalgarno sequences
How are Archaeans like eukaryotes?
DNA packing
Bidirectional replication
Multiple orgins of replication
Promotors
RNA pol