What compound will you need to use to visualize the amino acids on thin layer chromatogram?

A student seperates a mixture of octane and 1-octanol using thin layer chromotography. Which compound will move faster with tolunce. Give reason.

You are a chemist working in a lab who is analyzing polar samples with thin layer chromatography. What type of solvent do you think would be ideal for your tests? Why?

α-helices and β-sheets are two types of secondary structure found in polypeptides.

a. What phi and psi angles describe the amino acids in a helix and sheet respectively?

b. Draw a representative diagrams, with appropriate labeling, to illustrate a helix and a sheet. On your diagram label the hydrogen bonds that are responsible for providing stability to these structures. You must illustrate your bonds using the appropriate H-bond donor and H-bond acceptor.

a. Outline the steps of the ribosome cycle. At what stage do the ribosomal subunits bind to each other? To mRNA? What causes them to dissociate when protein synthesis is complete? In detail.

b. Outline the steps by which aminoacyl tRNA synthetases charge tRNAs. How can some organisms get away with having fewer than 20 synthetases, yet still charge tRNAs with all 20 amino acids? In detail.

1. Outline the steps of the ribosome cycle. At what stage do the ribosomal subunits bind to each other? To mRNA? What causes them to dissociate when protein synthesis is complete?

2. Outline the steps by which aminoacyl tRNA synthetases charge tRNAs. How can some organisms get away with having fewer than 20 synthetases, yet still charge tRNAs with all 20 amino acids?

1. It is possible to convert the cysteine (Cys) that is a part of Cys-tRNACys to alanine (Ala) by a catalytic reduction. If the resulting Ala-tRNACys were added to a mixture of ribosomes along with tRNAs correctly charged with the other 19 amino acids, all the other cofactors and proteins needed to make proteins in vitro, and mRNA for Insulin, what effect on the primary structure, tertiary structure and function of the insulin thus made would you expect?

Describe the evidence for the fact that DNA is the genetic material and the sequence of events leading from the sequence of nucleotides of DNA to the sequence of amino acids in proteins and their secretion. Include in your answer:

a. the early evidence for the location of genes on chromosomes, the first evidence that DNA was the genetic material, and that genes determined the structure of proteins

b. a description of the mechanisms and structures involved in of transcription and translation c. a description of the cellular structures involved in protein synthesis and secretion

2. Describe the mechanism of targeting of proteins to the secretory pathway. Be sure to provide the step-by-step molecular mechanism of entry of proteins into the ER.

3. Outline an experimental progression involving site-directed mutagenesis to test the hypothesis that basic (positive) amino acids are important for opening a voltage gated ion channel.

Part 2 1. Discuss the difference between a genomic and cDNA library. Give details with respect to the preparation techniques.

1. The Da-Da-Da-Dah sound at the beginning of the first movement is called a ______________.

2. The form of the first movement is ___________________ form.

3. The tempo marking for the first movement of Beethoven’s Symphony No 5 is _____________.

4. The main theme of the first movement is punctuated with two __________________ and then followed by a third one before moving to the bridge

5. The _________________ play the bridge theme first in the exposition.

6. The tempo marking for the second movement of the symphony is __________________.

7. The form of the second movement is called ________________________.

8. The tempo marking for the third and fourth movements of the symphony is _______________.

9. The form for the third movement is called _______________________.

10. The form of the fourth movement is called _____________________.

Quaternary Structure

Quaternary structure represents the three-dimensional (3D) structure of one functional protein.

25. The 3D quaternary structure is facilitated by interactions between which portions of the polypeptide chain? (Select one)

1. Backbone atoms

2. Side chains/R groups

26. List the different types of interactions that can occur at the level of quaternary protein structure.

1. Covalent bonds

2. Interactions between individual amino acid R units that are near to each other in the linear

3. sequence

4. interactions of individual amino acid R groups between different chains

5. Individual amino acid R units that are separated from each other by a large distance along the linear sequence of amino acids.

27. How many polypeptide chains are present in the Quaternary structure of a protein?

28. When proteins have multiple polypeptide chains, what are the individual polypeptide chains called?

29. Find an example of a functional protein that is composed of multiple polypeptide chains (other than the example given in class). Provide the name of the protein below.

30. Draw a representation of the protein named above (in question 29). Be sure to decipher the different subunits.