Tuesday November 16th

Brett Laurie

10/16/10

Period 4

Scribe

Lately in class we have been learning about DNA and RNA. There is a lot of information on it and can get confusing but once you get it, it clicks. The last couple of classes we have been talking about replication specifically.

DNA: We learned earlier in the unit that nitrogen base A bonds with T and G bonds with C.

A-T

T-A

C-G

C-G

G-C

T-A

So this is your strand of DNA. To replicate it, something has to split in half. There is a specific enzyme called polymerase that breaks down the hydrogen bonds and “unzips” the DNA.

• -T

T- -A

C- -G

C- -G

G- -C

T- -A

The nucleotides floating around bond to the 2 separate strands of DNA.

A-T A-T

T-A T-A

C-G C-G

C-G C-G

G-C G-C

T-A T-A

So now you have a new DNA molecule.

RNA: Changing DNA into RNA: Transcription. We learned 2 different things about RNA. Translation and Transcription. Transcription is the actual process of the replication of RNA and Translation is how it makes proteins.

(translation)

(transcription)

Transcription:

A-T

T-A

C-G

C-G

G-C

T-A

So you have your DNA molecule and you want to produce RNA. First thing to know is instead of a T in RNA, it is a U. A bonds with U and G bonds with C. So first the enzyme breaks the molecule in half.

A- -T

T- -A

C- -G

C- -G

G- -C

T- -A

One of the 2 separate strands is already RNA except for the Ts need to be turned into Us.

A-

U-

C-

C-

G-

U-

That’s your mRNA strand. mRNA are messengers that can fit through the nucleus wall openings and get a message to the ribosome’s to make proteins. That other strand of DNA gets new nucleotides to bond with it.

Translation:

A-

U-

C-

C-

G-

U-

The mRNA goes and docks on top of a ribosome.

AUCCGU

Amino Acids, which produce the proteins in the ribosome, get hooked by an anticodon. A codon is 3 letters in a sequence of RNA and an anticodon are nucleotides that match up to a sequence when it is doced on a ribosome and they carry amino acids. So say UAG hooked an AA(amino Acid). The UAG would hook up with the first codon because these letters correspond. The AA is put into the ribosome but you need 2 AA to make protein. So GCA takes an AA and docks on the second codon and drops the AA in to make proteins. Once the process is finished, the anticodons go back to work.

AUCCGU

UAG GCA

AA AA

That is all we learned. The homework is 13.1 &13.2 notes and the Tribune Project. The notes are due Wedensday 17 and the tribune project is due Monday 22.

LEXIE

by the way- dambi is so cool for helping me upload this post onto moodle. she is the best!