How DNA was discovered!

Heres a 20 minute video about how James Watson discovered DNA! Told from the man himself!

http://www.ted.com/talks/james_watson_on_how_he_discovered_dna.html

Thanks to Jack G for reminding me!

Friday, 11/18

In class on Friday, we did a lab regarding protein synthesis. The point of the lab was to understand the roles of mRNA(messenger RNA) and tRNA(translation RNA) in protein synthesis. To help our understanding, we constructed a model of protein synthesis. FIrst, we built two stands of DNA. Then we separated the two stands and built the corresponding strand of mRNA (using uracil instead of thymine). After that, we separated the mRNA strands form the DNA strands and made a codon of the mRNA strand, or the tRNA strand. Then we attached an amino acid to the right tRNA molecule by it's R-group. DNA polymerase is the enzyme needed for DNA replication. The enzyme used to build mRNA and tRNA is RNA polymerase.

The two steps in protein synthesis are transcription and translation. Transcription takes place in the nucleus and forms mRNA strands from one of the strands of DNA. Translation occurs in the cytoplasm on a ribosome and the codons of mRNA (tRNA) are translated into amino acids to form proteins.

Our homework for this weekend was to finish UP 23-28, UP 39-40 (online), UP 15-20, read section 13.3, and finish our tribune article, all due on Monday.

Don't forget to study for the unit test this Tuesday! 


Next scribe will be Elizabeth.

EXTRA CREDIT!

Alright guys... 2 extra credit opportunities!

Click on this link and answer the following questions.

1. What color is the RNA backbone in this activity?

2. What 3 amino acids make up the polypeptide chain at the end of the protein synthesis activity?

First 4 people to email me the answers will get extra credit!

Opportunity #2... click on this link, enter in your FULL name... and complete the 'quiz'. You will get extra credit based on your score. This opportunity will expire on Sunday at midnight!

11/16

Today in class we went over our homework from last night which was the Double Bubble Map for DNA vs. RNA.

Then for the rest of the period we went over protein synthesis. We took notes on this during class and Mrs. Stein put up the notes on Moodle. We only took notes on the first two slides in the powerpoint. If you are a person that likes having organized notes, then read through the rest of the slides in the powerpoint. These are the two slides we took notes on:

There are two parts to protein synthesis: transcription and translation. Mrs. Stein had us draw this picture. It represents the whole process of protein synthesis. As you can see transcription happens in the nucleus and translation happens in the cytoplasm on a ribosome.

Here is a picture that represents what happens in the translation process more clearly. In translation, mRNA attaches to a ribosome. A tRNA carries only ONE amino acid. In the picture, the cloves shape is the tRNA and the little circle that it is holding represents the amino acid. The anticodon on the tRNA matches with the codon on the mRNA. Once the tRna has finished, it LEAVES the ribosome. All the amino acids join into a long chain called a polypeptide. This long polypeptide is what makes PROTEIN. Remember: Amino acids MAKE UP protein.

HOMEWORK: 1) 13.1 & 13.2 Flow Map of Protein Synthesis is due TOMORROW! If you need help use Moodle because Mrs. Stein put up some animations that are very helpful.


2) Tribune Article due Monday 11/21


3) There will be a test on Tuesday 11/22 on everything that we have covered in this chapter. Use your objectives to help you study!


The next scribe will be Andrijana.

Class 9/15

Today at the beginning of class we handed in UP 7-14. Then, we had a reading check on the reading from last night, which was 12.3. After the reading check we took some notes. Below are the notes we took today.

DNA & CHROMOSOMES: LARGEST- Chromosome (46)

Gene: segment of DNA which codes for protein.

Double Helix

SMALLEST- nucleotides (sugar-dexoyribose, phosphate, nitrogen bases)

DNA REPLICATION:

~During S-phase of interphase

-2 copies needed for mitosis

~Each strand serves as a template for the new strand

~produces 2 identical DNA molecules

~semi-conservative replication: each new molecule contains one old strand and one new

Here are some links to help with these notes:

http://www.fed.cuhk.edu.hk/~biology/teaching/genetics/animations/transcription.htm

http://www.susanahalpine.com/anim/Grolier_Anims/DNA.htm

Homework:

1. Read 13.1-Double Bubble Map: DNA vs. RNA- due tomorrow (11/16)

2. Read 13.1 and 13.2- Flow Map: "Protein Synthesis"- due Thursday

3. Tribune Article- due Monday

4. Unit Test- Tuesday

The next scribe will be GABBY

Scribe 11/14

At the start of class today our UP pages 7 and 8 were checked. They will be turned in tomorrow along with pages 9-14. Tonight you will also read 12.3 in the textbook. Due on monday is the Tribune article and tuesday will be our unit test.

Today in class we did a lab that can be found on UP pages 13 and 14. We were instructed to create a strand of DNA based on the code it gave us for the left strand. When we completed the 9 rung ladder of DNA it should look like this:

Then you were to duplicate the DNA strand and should come out with two identical DNA ladders.

Sribe for 11/10/11

Even though the class period was about 40 minutes long, we covered a lot of stuff in class.

HOMEWORK:
-Read and Understand UP 11-14 (lab)

-UP 7-8

-Make magazine article or tribune (Due: 11/21)

CLASS ACTIVITY:

We went to our lab groups to discuss the following terms: DNA, Protein, Gene, Nitrogen Base, Phosphate, Nucichleotide, Structure. We took this words and explained them by writing up a paragraph to define all of them. All the groups presented their paragraph in class and were judged by mrs. Stein on how well they were defined in the paragraph. Then when comparing everyones performance, she found the word gene, as she expected to be the one that everyone didn't do so well on. This brings us to the question:

What the definition of a Gene?

INCORRECT ANSWER: "things that make up who we are"
CORRECT: Segment (unit) of DNA which codes for proteins...these proteins determine our traits.

CLASS NOTES:

DNA- deoxribonucleic acid

SLIDES

DNA STRUCTURE AND COMPONENTS

*Double Helix- 2 strands form a twisted ladder
*Subunits of nucleotides contain:
- Sugar
- Phosphate group
- Nitrogen group
*Backbone ("uprights") made of deoxyribose and phosphate

NITROGEN BASES

*Purines- 2 rings
- Adenine
- Guanine
*Pyrimidines- 1 ring
-Thymine
-Cytosine
*Order of the bases contains the "code"to make proteins