Chapter 17 - Protein Synthesis Flashcards
Function of rRNA
Binds with proteins to make ribosomes
T or F - Ribosomes read from 3 to 5
F - 5 to 3
Each codon codes for _________
An amino acid
What catalyzes RNA synthesis?
Rna polymerase
What are transcription factors?
Proteins that mediate the binding of RNA polymerase and initiation of transcription
Transcription Initiation complex
Completed assembly of transcription factors and RNA Polymerase II bound to a promoter
Function of TATA box
Promoter that is crucial in forming the initiation complex in eukaryotes
The genetic code is _____ bc most amino acids have more than one codon. It is not ______ bc each codon specifies only one amino acid.
Redundant
ambiguous
Summarize the translation process.
- Begins at AUG start codon
- tRNA brings the correct amino acid to correct place on the mRNA
- Amino acid is transferred to growing peptide chain
- Cont until stop codon is found
- Process ends by releasing newly made peptide/protein
In prokaryotes, transcription and translation are ______. In euk cells the nuclear envelope _____ them and _____, _____, and ______ occur in the nucleus.
Coupled
Separates
Splicing, adding a cap, adding poly-A tail
Two types of substitutions
Missense - mutations that code for wrong amino acid more common
Nonsense - mutations that change a codon into a stop codon, nearly always resultin kn nonfunct protein
Benefits of mutation
Provides raw marerial for evolution thru genetic diversity
Mutation can immediately benefit organism if in somatic cells, and their offspring if mutation occurs in germ line cells.
What is the relationship between DNA, a gene, and a chromosome?
Chromosome contains hundreds of genes, which are made of DNA.
In euk cells, transcription can’t begin until
Several transcription factors bind to the promoter
T or F - Exons are cut out before mRNA leaves the nucleus.
F - Introns are cut, Exons exit
