Fatty Acid Spiral

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Fatty Acid Spiral

• Two carbons at a time are cleaved from a fatty acyl-CoA as acetyl-CoA.

• This cleavage continues until the entire fatty acid has been converted into acetyl-CoA.

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Amino Acid Catabolism

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Transamination and Oxidative Deamination• Amino acids from food are de-aminated via transamination. The carbon skeleton that remains can be used from

anabolism or catabolism. The amine group can be used from synthesis of nitrogen containing compounds (anabolism) or can be excreted at urea.

• In order to be excreted, the amine group must be removed at NH4+ via oxidative deamination.

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Complementary Amino Acids

• Nonessential amino acids are those that can be synthesized by our bodies.• Essential amino acids are those that must be obtained from foods because they cannot be efficiently

synthesized by our bodies.• Our diets must contain a reasonable ratio of the essential amino acids in order for our bodies to maintain

health.– Meat, eggs, soy and milk contain the essential amino acids in a similar ratio to that needed by humans.– Fruits, vegetables, nuts, seeds, and grains tend to be high in some and low in others. They do not

contain similar ratios to that needed by humans. Thus, they should be consumed such that the amino acids they contain will ‘complement’ each other.

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Glucogenic and Ketogenic Amino Acids• Ketogenic amino acids are those whose carbon skeletons can enter the Krebs cycle for energy production, or can form ketone bodies via

ketogenesis for energy storage.• Glucogenic amino acids are those whose carbon skeletons can enter the Krebs cycle for energy production, or can form glucose via

gluconeogenesis for energy storage.• All amino acid carbon skeletons can be used for fatty acid biosynthesis via acetyl-CoA.

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Problems1. What type of molecules undergo transamination during catabolism?

2. Put the following in order of occurrence: Krebs cycle, glycolysis, oxidative phosphorylation, ETC

3. An 8 step cycle in which two carbons enter as acetyl-SCoA and two carbons exit as carbon dioxide describes __________.

a. Glycolysisb. Fatty acid oxidationc. Gluconeogenesisd. Pyruvate oxidatione. Krebs cycle

4. A 10 step process in which glucose is broken down into two units of pyruvate describes __________.a. Glycolysisb. Fatty acid oxidationc. Gluconeogenesisd. Pyruvate oxidatione. Krebs cycle

5. Palmitic acid has 16 carbons in it’s chain. a. How many turns in the fatty acid spiral does it take to oxidize palmitic acid?b. How many acetyl-SCoA molecules form from one molecule of palmitic acid?c. How many reduced coenzymes of NADH and FADH2 are formed?d. How many ATP would result strictly from the fatty acid oxidation of palmitic acid?