Ch. 2 DNA, RNA, And Protein Flashcards
___ are regions of DNA that are transcribed to give RNA that can be translated to protein or used directly.
Genes
Structure of a typical structure gene contains ___ and ___ ___ ___.
Promoter and transcription stop signal
___ ___ synthesizes RNA at the transcription bubble.
RNA polymerase
___ are added to create RNA complementary to the template (non-coding) strand.
Ribonucleotides
Eukaryotic transcription
- eukaryotes have three different RNA polymerases
- RNA polymerase II binds to TATA and initiator boxes
- eukaryotes require specific transcription factors
Mono-cistronic vs Poly-cistronic
- eukaryotes transcribe genes in single units, where each RNA encodes for only one protein
- prokaryotes transcribe genes in operon as one single mRNA then translate proteins as separate units
Positive regulation -
Genes are expressed only when the activators give a positive signal
Negative regulation -
Genes are expressed only when the repressor is removed
___ ___ will not activate lactose operon alone, lactose must be present.
Crp binding
If lactose is available, ___ will convert some lactose into allo-lactose which acts as an inducer.
B-galactosidase
Autogenous regulation -
Repressor or activator binds to the promoter of its own gene
___ ___ are far from the promoter but may loop around to directly bind to the mediator complex.
Enhancer sequences
___ ___ prevent transcription factors from binding to the wrong promoter.
Insulator sequences
The eukaryotic transcription factor has two domains, the ___ ___ ___ bind DNA at the promoter, and the ___ ___ initiates RNA polymerase actions.
DNA binding domain
Activator domain
The eukaryotic transcription factor, AP-1 -
Consists of two different proteins that works as a dimer
AP-1 belongs to a family of DNA binding proteins called ___ ___.
bZIP proteins
To activate transcription, AP-1 must first be activated by phosphorylation by the ___ ___.
JNK kinase
Epigenetics -
Any heritable change in DNA other than changes in nucleoside sequence
___ add new methyl groups, and demethylases removed unwanted methyl groups.
Methylases
___ ___ ___ arrives and attracts HDAc, the histones aggregate.
Methylcytosine binding protein (MeCP)
The closeness of histones excludes any DNA binding proteins hence turns off ___ ___.
Gene expression
Codon bias -
Each organism has a preference as to which triplet codon is used most often for the particular amino acid
The first base of the anticodon binds the third base of the codon in the mRNA and it can wobble allowing ___ ___.
Nonstandard base-pairing
Start codon
AUG
Anticodon
UAC
First amino acid
Methionine
___ have their own DNA.
Mitochondria
___ will be the template strand.
Missense strand
RNA modification
- polyA tail
- intrumo
- capping capG
