Catalytic Mechanism of Carboxypeptidase A

1) Carboxypeptidase A, a zinc-containing enzyme, hydrolyzes the C- terminal peptide bonds of polypeptides and/or proteins. In the enzyme- substrate complex, the zinc ion is coordinated to three enzyme side chains, the carbonyl oxygen of the scissile peptide bond, and a water molecule. A plausible model for the enzyme's reaction ...continues

Metal ions as cofactors

Many enzymes use metal ions as cofactors. Carboxypeptidase A is one such enzyme, requiring a zinc ion for catalytic activity. Carboxypeptidase A exploits the chemistry of its zinc ion, which is positively-charged, in order to increase the rate of the reaction. (I) Explain the role of the zinc ion in the first step of catalysis ...continues

Scissile Bond

If the following peptide was the substrate for Carboxypeptidase A. Which of the indicated red arrows correctly identifies the scissile bond? See attached file for full problem description.

Michaelis-Menton Kinetics

If the initial rate of an enzyme-catalyzed reaction is measured as a function of substrate concentration in the presence and absence of 10 uM of an inhibitor (I). Purified enzyme concentration is 50 uM. The reaction follows classical Michaelis-Menton kinetics. The data obtained are charted below. See attached file for full pr ...continues

Trisaccharide

Provide the complete & accurate systematic name for this molecule. Be sure to include the correct names, in order, of the sugar residues, the correct numeric linkage for the glycosidic bonds, and any necessary information about anomeric carbons. See attached file for full problem description.

Lipids

See attached file for full problem description. Which structures contain saturated fatty acids or saturated fatty acid derivatives? Select all answers that apply. a. A b. B c. C d. D e. E Which structures contain unsaturated fatty acids or unsaturated fatty acid derivatives? Select all an ...continues

Reaction process

Lactate dehydrogenase catalyzes the reversible reaction: Pyruvate + NADH + H^(+) → Lactate + NAD^(+) Given the following facts, (a) tell in which direction the reaction will tend to go if NAD^(+), NADH, pyruvate, and lactate were mixed, all at 1 M concentrations, in the presence of lactate dehydrogenase at pH 7; (b) ...continues

Glycolysis and Gluconeogenesis

The following questions refer to the mitochondrial enzyme MALATE DEHYDROGENASE. What is the chemical reaction, within the citric acid cycle, that is catalyzed by malate dehydrogenase, and which substrates, products, and/or cofactors are involved? The reaction from the previous question is classified as a dehydrogenatio ...continues

Electron Transport Chain

Rank the following redox-active coenzymes and prosthetic groups of the electron-transport chain in order of increasing electron affinity. Each species must be matched with a different number ranking. cytochrome a coenzyme Q FAD cytochrome c NAD+

Free energy and its affects

What affect does the presence of metal ions like Mg++ in the cell have on free energy of hydrolysis of ATP?? raise, lower, or no affect why??