Individuals lacking an enzyme in the urea cycle have severe problems as a result of ammonium accumulation. Administration of benzoic acid stimulates formation of benzoylglycine (hippuric acid), a non-toxic compound that can be excreted in urine. Why does this help?

For each of the following TCA Cycle enzymes, list the name of the enzyme in the fatty

      acid b-oxidation pathway that is most similar in function and state why.

1. Succinate dehydrogenase

2. Fumarase                                           

3. Malate dehydrogenase                       

4. Aconitase

1. List two properties of ammonia that cause problems for cells trying to acquiring nitrogen. (Don’t just say ammonia is too scarce in the environment)

1. _______________________________
2. ______________________________

Describe in general terms how the cell solves this nitrogen acquisition problem (no enzyme names):

____________________________________________

The enzyme succinate dehydrogenase acts on succinate and convert it to fumarate tn the TCA cycle . In the presence of malonate the apparent km reduced but the vmax remains unaltered. What can you conclude about the type of inhibition by malonate and the structure of malonate?

Describe in detail how to clone your “gene of interest” into a bacterial plasmid using EcoRI restriction enzyme and how to generate a large quantity of the DNA using competent E. coli. Why do you use competent bacteria for this?

Summarize the Metabolic Adaptations to exercise training for each of the following: (briefly describe the overall change and then the impact of that change)

-Fuel supply (CHO-FAT-PRO)

-Enzyme activity

-Oxygen utilization

-Lactate accumulation

-ATP Production/storage/turnover

Which two compounds require different amounts of O₂ for a complete

      combustion?

         (a) ribose and galactose                        (c) fructose and mannose

         (b) D-glucose and L-glucose                  (d) none of these pairs

Which sample of mammalian double helix DNA contains the most cytosine?

         (a) one that contains 28% G             (c) one that contains no G

         (b) one that contains 24% C             (d) one that contains 25% T

How many cycloalkanes have the formula C₃H₆?

         (a) one         (b) two          (c) three       (d) more than three

Competitive, irreversible inhibitors of HIV-1 protease:

         (a) permanently block the process of substrate binding.

         (b) usually form a stable complex with both enzyme and substrate.

         (c) usually form a reactive complex with both enzyme and substrate.

         (d) None of these statements are true.

Dr. Melody is preparing 30 µg of a new ‘unknown’ Lambda digest (with OgwXI), to be used for her class. She wants to set up a slight overdigestion using 3x the standard amount of restriction enzyme in a total volume of 300 μl, and has the following reagents:

l DNA @ 2 µg / µl

molecular water

10X reaction buffer

OgwXI restriction enzyme @ 5 U / µl

However, Dr. Melody messed up. This was her protocol: 15 μl λ DNA, 30 μl reaction buffer, 37 μl molecular water, 18 μl OgwXI

Which components are correct and which are incorrect?

Do you think this reaction will be successful anyway? Why or why not?

How should the reaction setup be corrected?

Show your calculations to justify your answer.

Your neighbors have been feeding the birds – a lot – and now they’ve got rats in their yard, happily feasting on the leftover birdseed. You don’t want the rats near your house, and having little regard for the life of vermin, you decide to place a little “deterrent” on your property. Nosing around in a lab, you find arsenic. OK, you are smart enough not to actually use it, but you can’t help but think about it...

If a rat ingests arsenic, the enzyme __________________________ will be inhibited, and the metabolic intermediate ___________________________ will NOT be converted to ___________________________ which is the key entry point to the energy-generating pathway known as the ___________________________. Instead, this metabolic intermediate will be shunted into the metabolic pathway known as ___________________________ which does not require the function of the inhibited enzyme. The glucose- derived end-product of this pathway is ___________________________ and the net energy yield from glucose is ___________________________ NADH and ___________________________ ATP.