The peptides and amino acids experiment relied on TLC and other qualitative tests. Why were IR or NMR spectroscopy not an option for analysis?..

If a polypeptide is composed of 319 amino acids, how many nucleotides were in the mRNA transcript for the polypeptide? Show your work (math).

Why is the Ramachandran Plot for Glycine symmetric and why is the plot asymmetric for all amino acids except (glycine, proline, pre-proline)?

For each tissue discussed in the chapter (liver, intestine, kidney, muscle and brain), list and discuss the amino acids that are physiologically relevant for that tissue.

Briefly describe how each of the following groups of molecules is produced in cells; polysaccharides, lipids, amino acids, proteins, purines/pyrimidines

A sequence of DNA reads: 5’ TCT GGC AAT CGC TAT 3’

1.What is the sequence of nucleotides on the complementary strand of DNA?

2.Which strand of DNA serves as the template strand – 5’ to 3’ or 3’ to 5’?

3.List the sequence of codons that result from the transcription of this DNA

4.What is the sequence of amino acids encoded by this DNA (Refer to the chart on the next page)?

5.How would the sequence of amino acids change if the first triplet of DNA read 5’ ACT 3’ instead of ‘5 TCT 3’?

1)Vitamin A and pro-vitamin A are molecules that contain only carbon and hydrogen atoms and do not have any amino acids. If scientists want to genetically engineer a plant to make pro-vitamin A, what type of gene or genes would the scientists need to insert in the plant cells? Would they insert a gene that codes for pro-vitamin A? If not, what type of molecule would the gene or genes have to code for? Explain your reasoning.

2)Scientists have identified genes for two enzymes needed to make pro-vitamin A. One of these genes comes from corn. If this gene from a corn plant is inserted in the DNA of a rice plant, will the sequence of amino acids in the protein produced by the rice plant be the same as the sequence of amino acids in the protein produced by the corn plant? In other words, will rice plants that have this gene produce the same enzyme as corn plants produce? Explain why or why not.

3)Once scientists have identified the genes for enzymes to produce provitamin A, how could they insert these genes in the DNA of rice plant cells? Suggest one possibility.

4)Would you recommend that scientists try to insert the genes for enzymes to produce pro-vitamin A into:

a. all the cells in a rice plant

b. the thousands of cells in each rice grain or

c. a small group of embryonic rice plant cells that can divide and develop into a rice plant?

Explain your reasoning.

5) To insert genes from one organism into a different organism, scientists often take advantage of the natural genetic engineering capabilities of bacteria or viruses. One type of bacteria genetically engineers plant cells by inserting part of its bacterial DNA into the plant cell DNA, thus producing recombinant DNA. The inserted bacterial genes code for proteins that:

• stimulate the genetically engineered plant cells to produce food molecules that only the bacteria can use
• stimulate these genetically engineered plant cells to divide and form a growth that bulges out from the stem or root.

Explain how this type of genetic engineering is useful for the bacterium.

1. Carbonic anhydrase catalyzes the reverse reaction (of course!): HCO3 - + H+  CO2 + H2O Initial velocities were measured at the following concentrations of HCO3 - (The enzyme concentration was 0.0025 mg/ml; the enzyme Mr = 29,100 Da.): [HCO3 -] mM 1.3 2.6 6.5 13.0 26.0

vo (µM/sec) 2.5 4.00 6.30 7.60 9.00

vo (µM/sec) with acetazolamide 1.17 2.10 4.00 5.70 7.20

a. Do the required calculations and graph the results as a Lineweaver-Burk plot. Use the X- and Y-axis scales provided or an excel graph; add labels and units to each axis.

b. Calculate (i) KM (ii) Vmax and (iii) the enzyme turnover number (kcat).