Multi-hit model

LOF mutations in the tumor suppressors APC and p53 and GOF mutation in the oncogene K-RAS establishing that multiple mutations in the same cell are needed for the cancer to form.

TLS Online TPP Program

#Id: 3664

#Unit 3. Fundamental Processes

Ribosomes are large ribonucleoprotein particles that contain more RNA than protein and dissociate into large and small subunits.

TLS Online TPP Program

#Id: 3665

#Unit 3. Fundamental Processes

Size comparisons show that the ribosome is large enough to bind tRNAs and mRNA.

TLS Online TPP Program

#Id: 3666

#Unit 3. Fundamental Processes

Aminoacyl-tRNA Formation Is Very Accurate, the frequency of mischarging is very low; typically, less than 1 in 1000 tRNAs is charged with the incorrect amino acid.

TLS Online TPP Program

#Id: 3667

#Unit 3. Fundamental Processes

Valyl-tRNA synthetase can sterically exclude isoleucine from its catalytic pocket because isoleucine is larger than valine.

TLS Online TPP Program

#Id: 3668

#Unit 3. Fundamental Processes

The protein-coding region(s) of each mRNA is composed of a contiguous, non-overlapping string of codons called an open reading frame (commonly known as an ORF).

TLS Online TPP Program

#Id: 3669

#Unit 3. Fundamental Processes

Translation starts at the 5’end of the ORF and proceeds one codon at a time to the 3’end. The first and last codons of an ORF are known as the start and stop codons.