Unit 5, Chapter 16 AP BIO

Central Dogma

The process by which DNA is transcribed into mRNA, which is then translated into polypeptides (proteins).

Gene

A segment of DNA that codes for a protein or RNA.

Template Strand

The non-coding strand or antisense strand used for transcription.

Coding Strand

The non-template strand or sense strand, which looks like mRNA but has T instead of U.

RNA Polymerase

An enzyme that binds to the template strand and adds complementary RNA nucleotides during transcription.

What role does the 5’ G nucleotide cap play in mRNA processing?

It allows mRNA to leave the nucleus, protects it from hydrolytic enzymes, and enables binding to the ribosome.

What is splicing?

The process of removing non-coding sequences (introns) and putting coding sequences (exons) back together.

Alternate Splicing

A process that allows exons to be put together in different orders, increasing protein diversity.

Translation

The process by which mRNA is translated into a polypeptide at the ribosome.

Start Codon

The codon (AUG) that signals the beginning of translation and corresponds to the amino acid Methionine.

Stop Codon

A codon that signals the end of translation, leading to the release of the newly formed polypeptide.

What is the triplet code in RNA?

RNA is read in 3-letter sequences called codons, where 1 amino acid corresponds to 1 codon.

How many DNA nucleotides are required to make a polypeptide that is 900 amino acids long?

54,000 nucleotides.