1. draw structures illustrating the hydrogen bonding between amide groups of peptide chains
2. what is the configuration of almost all naturally occurring amino acids at the α (alpha) carbon
3. why is an alpha amino acid such as alanine more acidic than a regular carboxyllic acid
4. strecker synthesis Formation dl-phenylalanine
5. outline the steps to synthesize the simple dipeptide AL (think about two amino acids that begin with an A and an L)
6. give the structure and name of the nucleosides in dna and rna
7. give the structure of most lipids of biological origin
8. which fatty acids are found in peanut, corn, and coconut oil

a) Draw the complete covalent structure of the tripeptide Met-Tyr-Arg, with trans peptide bonds, as it would exist at pH 7.

b) Write the 1-letter code for each of the three amino acids below the structure.

c) What is the overall charge of this peptide at pH 7?

d) What is the overall charge at pH 12?

e) This tri-peptide is reacted with 6M HCl and heat, which breaks-up the individual peptide bonds. The mixture of the 3 amino acids is then run through a cation-exchange column. Which of the amino acids will come out first, which second and which third?

How might a change in either nucleic acid (DNA or RNA) impact primary, secondary, tertiary, and quaternary protein structure? If the change, or mutation, in DNA results in several hydrophobic amino acids being replaced by several hydrophilic amino acids, how might that impact protein structure and function?

1. When part of a protein chain, the amino acid proline also lacks a backbone hydrogen bond donor; mutations to proline will delete a backbone hydrogen bond. List two reasons why proline mutagenesis is problematic for selectively studying backbone hydrogen bonds.

2. Draw chemical structures for the amino acids or hydroxy acids with these abbreviations: A, α, F, ϕ

3. Draw the structure of one of the 20 canonical amino acids whose side chain contains a hydrogen bond donor group. Propose a structure for an unnatural amino acid (you get to make it up!) to selectively test the effect of weakening or eliminating this hydrogen bonding ability (without dramatically changing the steric bulk or other functional groups on the side chain)

The deamination of glutamate with GLUTAMATE DEHYDROGENASE is called OXIDATIVE DEAMINATION.

1. What are the products of glutamate oxidative deamination? and what cofactor(s) is/are involved?

2. What α-ketoacid/amino acid pair connects glycolysis and amino acid metabolism?

Question 37

1. If the hormone LH is not present in a male ________.

   a.

   testosterone may not be produced

   b.

   spermatogenesis is not promoted

   c.

   fluids for semen will be overproduced

   d.

   excess testosterone is produced

Question 42

1. Which of the following is in the correct order for protein digestion?

   a.

   pepsin – peptides – peptidase – amino acids

   b.

   peptidase – peptides – pepsin – amino acids

   c.

   peptidase – amino acids – pepsin - peptides

   d.

   amino acids – peptidase – peptides - pepsin

A heart murmur is caused by ________.

Question 52

1. In the cardiac cycle, the diastole is ________.

   a.

   the relaxation of heart muscle

   b.

   the contraction of heart muscle

   c.

   the closing of the atrioventricular valves

   d.

   the opening of the semilunar valves

Question 57

1. Barrier methods of birth control, such the diaphragm, physically block sperm entrance to the va gina but are more effective with a spermicide.

   a.

   TRUE

   b.

   FALSE

Discuss Glycolysis process and mention the sequence of enzyme-catalyzed reactions by which glucose is converted into pyruvate.

Match the following questions with 1,2 or 3

insulin and glucagon ?

hormones can activate metabolism through?

How is glycolysis regulated?

1.phosphorylation, gene expression/protein degradation, enzyme localization

2.These hormines dictate whether glucose flows through glycolysis or gluconeogenesis

3.Low Blood Glucose -----> increase glucagon: Phosphorylation of bifunctional enzyme: --inactive PFK2, active FBPase2 --decrease F-2,6-BP --decrease PFK1 activity ; Phosphorylation of pyruvate kinase --decrease pyruvate kinase activity

Discuss the following:

1. Two factors that affect the activity of an enzyme. Name the enzyme and tell whether they increase or decrease enzyme activity.

2.Three ways in which sugars can be used other those going directly into glycolysis – just list them with the name of the sugar (For example, _______ can be used to make ________)

The structure and properties of amino acids determine the structure and properties of proteins and, therefore, their function. How do amino acids and peptide properties dictate protein structure and function? In your explanation, please include at least one representation and the key terms hydrophobicity, hydrogen bonding, electrostatic interactions, acid-base property