Question

rna lab report

Answer 1

a codon is mutated, say from GGU to CGU, is the same amino acid specified?_______

Questions:
1. Select one of the observations (either clue 8 or 9) from the table: Possible Clues to Copying the Code (DNA replication and transcription/translation). This evidence was used to understand DNA replication (DNA passing information from one generation to the next). Write an explanation detailing why this clue represents solid data and is not an opinion or an inference. Questions:
1. Select one of the observations (either clue 8 or 9) from the table: Possible Clues to Copying the Code (DNA replication and transcription/translation). This evidence was used to understand DNA replication (DNA passing information from one generation to the next). Write an explanation detailing why this clue represents solid data and is not an opinion or an inference.

2. (a) Why is it sometimes difficult to tell the difference between an observation and an inference? (b) Which of the clues included in the table is an inference? Explain why. (c) Which of the clues included in the table is an opinion? Explain why.

3. Francis Crick was the first to recognize that information flows from DNA to RNA to protein. This concept is known as the Central Dogma. At the time the Central Dogma was first stated, it was an inference based on observations. Explain why.

4. Scientists bring preconceived ideas to their work. Often these preconceptions make it difficult for them to objectively interpret their data. From the information provided in the Copying the Code module, state one example of a preconceived idea that biased scientific thinking and slowed finding the answer to how DNA is a copying mechanism for hereditary material.



Table: Possible clues to Copying the Code (DNA replication and transcription/translation).
Clues Evidence supporting
replication Evidence
supporting
transcription /translation Not evidence for replication or
transcription
/translation
1. When DNA from a virus is injected into a bacterium, the bacterium produces viral (phage) protein.
2. Protein synthesis occurs in the cytoplasm of cells.
3. When a gene is destroyed through exposure to radiation, its capacity to produce an enzyme stops.
4. Bacteria grow for many hours in a heavy nitrogen medium.
5. If you understand the structure of RNA then you will know how proteins are made.
6. RNA is a nucleic acid found in both the nucleus and the cytoplasm.
7. Uracil hydrogen bonds with adenine in place of thymine during RNA synthesis.
8. Bacteria with heavy nitrogen in their DNA, when transferred to a culture tube with lighter nitrogen, formed DNA molecules that were made of half heavy and half light nitrogen.
9. When DNA is removed from a cell and placed in a test tube containing the enzyme DNA polymerase and nucleotides, new copies of the original DNA are formed.
10. Since there is greater variety in the protein molecules than in the DNA molecules of an organism, protein must contain the genetic code.


Examine the section of the DNA website entitled “Reading the code” before working on the following questions.
5. What question about reading DNA code did Marshall Nirenberg answer using the cell-free system developed by Zamecnik and Hoagland?

6. What question does Sydney Brenner ask in “Defining the gene?” Explain why this was an important question to understand how DNA codes for protein. How does the sequence of bases correspond to the sequence of amino acids?

7. George Gamow thought that three bases in DNA corresponded to one amino acid. To confirm this idea, Marshall Nirenberg used a synthetic RNA containing only one kind of base. What question was his experiment attempting to answer?

8. Briefly describe Seymour Benzer’s experiment that answered the question: “Do mutations in the DNA sequence of a gene correlate with protein changes?”


9. Marshall Nirenberg and Heinrich Matthaei used mRNA made up of repeating uracil nucleotides in a cell free extract. They obtained amino acid chains consisting of phenylalanine. What did they learn when they asked the question, ”What happens when mRNA made up of only cytosine, alanine, and guanine are placed in a cell free extract?”

10. Explain how the structure of tRNA helps it to deliver the correct amino acid to the corresponding mRNA codon at the ribosome.

Sketch the structure of a tRNA molecule, making sure to label the amino acid and the anti-codon.





11. List or draw sequentially the steps involved in protein synthesis. Start with the DNA code in the nucleus, and try to end up with a polypeptide in 10 steps. Title your work “10 easy steps to synthesizing your protein.”



12. Explain why a mutation that occurs in a codon may not result in a change of an amino acid in the protein sequence. Use the genetic code chart to give an example of how this might occur. (Th

Answer 2

please help me

Answer 3

i just need the answeres thats all