c. The anticodon on the tRNA molecule that is complementary to the mRNA codon described above. d. The amino acid that would be carried by the tRNA molecule described above. In Henry's other CYP2C9 gene, the 430th nucleotide has been changed from a cytosine (C) to a thymine (T). This mutation converts a CGT triplet code in the coding strand of the DNA molecule to TGT. Beginning with this triplet code on the DNA, describe the effect that this change would have on the following: a.
The second step is the binding of RNA primase in the initiation point of the 3-5 parent chain. RNA nucleotides are the primers for the binding of DNA nucleotides. The third step the 3-5 proceeding strand uses a 5-3 template is called the leading strand because DNA polymerase can read the template and continuously adds nucleotides. The fourth step the lagging strand reads the fragments and removes the RNA primers. The gaps are closed with the action of DNA polymerase and DNA ligase.
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
Controlling the Code: molecules at work The lac operon 2. (a) Write a description of the role of the operator in B-gal production. • What is the operator? The operator is a segment of DNA located between the promoter and the enzyme genes. It acts as a switch by determining whether RNA polymerase can attach to the promoter and start transcribing.
DNA specifies the synthesis of proteins, However, a gene does not build a protein directly, instead it dispatches instructions in the form of RNA, which then programs protein synthesis. This molecular chain of command is from DNA in the nucleus then to RNA then to protein synthesis in the cytoplasm. The two main stages are transcription and translation, transcription is the transfer of genetic information from DNA into an RNA molecule, translation is the transfer of the information from RNA into a protein. Describe each stage of the flow of information starting with DNA and ending with a trait. Information will always start with DNA then it will travel to the RNA and then the protein.
Test your knowledge Match the correct functions For each of the enzymes in questions, 1-5, choose an answer (a-e) that most closely describes the functions of the enzymes Question 1 helicase Question 2 DNA polymerase 1 Question 3 ligase Question 4 DNA polymerase 111 Question 5 RNA polymerase Answers (a) removes the RNA primers during replication (b) performs transcription (c) unwinds DNA for DNA replication (d) adds nucleotides during DNA replication (e) forms phosphodiester bonds between Okazaki fragments Question 6 Which of the following are the nucleotides found in RNA (a) A, C, G, T (b) A, C, G, U (c) T, C, G, U (d) A, T, G, U (e) U, C, T, A
And that is about the only similarity they share. DNA contains the nucleotide T whereas RNA contains U. RNA copies the genetic information found within DNA and uses it to assemble protein, as well as ribosomes. Therefore, RNA is a critical part in protein synthesis. It is directly involved in it, but DNA is indirectly involved in this process. Ribose sugar is more reactive since of its C-OH (hydroxyl) bonds.
stores proteins and alot of exporting (sending stuff out of the cell) 3. In which part of the cell would you expect to find nucleotides? building block for DNA, DNA found in the nucleus 4. Name the two organelles involved in energy conversion.chloroplast and mitochondria 5. What are the basic functions of the organelles in chapter 4?