How Genetic Information Flows From DNA to RNA to Protein

Give an example of a codon and the amino acid it codes for:

AUG; codes for Met

True or false: Mutations are bad

False

How translation begins and ends:

Initiation: First the mRNA binds to the the smaller ribosomal subunit. Then the special initiator tRNA binds to the start codon of the mRNA (AUG). This signals translation to start. Termination: When the ribosome reaches the stop codon (UAA, UAG, UGA), the translation is stopped.

What has the universality of the genetic code allowed scientists to do?

It allows scientists to produce proteins in order organisms by transplanting genes.

How does a gene provide information for a protein, i.e. how does information flow through a cell? Be sure to define transcription and translation

The gene is a segment of DNA that encodes for a particular protein, and this information flows from DNA to mRNA through the process of transcription. This mRNA then travels outside the nucleus into the cytoplasm and encounters a ribosome, where the process of translation begins. This is where the polypeptide amino acid chain is manufactured.

If the sequence in DNA is GGATTA what would be the two amino acids coded for?

Proline, asparagnine

What happens to mRNA before leaving the nucleus?

RNA processing occurs. One type of processing is when the cap and tail is added to the mRNA strand. These extra nucleotides protect the mRNA from enzyme attack and deterioration. RNA spicing also removes and introns and joins the exons before the mRNA is allowed outside of the nucleus.

What are the consequences on the protein if there is a nucleotide insertion or deletion in the DNA?

The codons are thrown out of frame and all the amino acids after the insertion/deletion will vary. This will cause significant damage to the protein.

The flow of information from gene to protein is based on a _________ code.

triplet

Garrod didn't work directly with genes, but what did he propose what the reason for different phenotypes in the individuals he was studying?

Garrod proposed that the primary reason for the different phenotypes in individuals was the presence or lack of an enzyme.

Beadle and Tatum came up with the hypothesis:

Hypothesis: Each gene codes for a particular enzyme.

This hypothesis has since been refined by scientists later in history to:

Modified hypothesis: Each gene codes for a particular polypeptide.

What are the consequences on the protein if there is a nucleotide substitution in the DNA?

One amino acid MAY change and alter the protein (Unless it's a silent mutation)

How transcription begins and ends:

Transcription begins by the RNA polymerase attaching to a specific region of the DNA called the promoter (Also known as initiation). Transcription ends when the RNA polymerase reachers a region of DNA known as the terminator. This signals the RNA Polymerase to detach from the DNA.