Saturday
May 18, 2013

Homework Help: biochemistry

Posted by an on Thursday, December 9, 2010 at 8:21pm.

I have three questions. I don't even know where to begin.

1.
a) If an in vitro fatty acid synthesizing system is supplied with [2-14C]-acetyl CoA as the only source of radioactive label along with all other necessary cofactors/reactants for net fatty acid synthesis, in what position(s) will the label appear in newly synthesized palmitic acid? (Note that the in vitro system lacks acetyl CoA carboxylase)
b) If instead 2,2-dideuteromalonyl CoA was supplied as the only source of label, how many deuterium atoms would be incorporated into palmitate and where would they appear?
c) If [3-14C]-malonyl CoA were used in the above reaction, which atom(s) in palmitate would be labeled?
d) Describe the pathway by which some of the carbons in an odd-chain fatty acid can undergo net conversion to carbohydrate.

2. A mammal on a particular diet expends 10,000 kJ of energy per day while excreting 40g of urea. Assuming that protein is 16% N by weight and that its catabolism yields 18kJ of energy per gram, what percentage of the mammal's energy needs are met by the degradation of protein?

3. [3-14C]-Pyruvate was administered to isolated liver cells in the presence of sufficient malonate to completely block succinate dehydrogenase. After a 30-minute incubation period, isocitrate was isolated from the reaction mixture and was found to contain 14C at both C2 and C4: Explain the presence of isotopic label at the indicated positions.

Any help would be appreciated! Thanks!

No one has answered this question yet.

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Biochemistry 1 - 1. a. What is a polyunsaturated fatty acid? b. What are trans-...
Biochemistry - What are the structures of the products of a complete acid ...
Biochemistry - What are the structures of the products of a complete acid ...
nutrition - A fatty acid that contains a chain of 10 carbons and one double bond...
Biology - Three fatty acids form a triglyceride with one glycerol. What ...
Biochemistry - The quantity 432mg of a monoamino monocarboxylic amino acid is ...
physiology - Heres the scenario: You stop at McDonald's and buy a Sausage ...
Math grd 12 - You are setting a system programing codes for a universal TV ...
chemistry - when 1.00 g of stearic acid ( a saturated fatty acid) is dissolved ...
Biochemistry - I have asked for help from other classmates and we are so lost. ...

For Further Reading

Search
Members
Community