1 / 6

Chapt. 39

Chapt. 39. Ch. 39 Student Learning Outcomes : Explain basic synthesis of nonessential amino acids Uses glucose derivatives (glycolysis, TCA) N sources often other aa Describe important cofactors: PLP (from Vitamin B6) for transaminations FH 4 (tetrahydrofolate) for 1C;

krista
Télécharger la présentation

Chapt. 39

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapt. 39 • Ch. 39 • Student Learning Outcomes: • Explain basic synthesis of nonessential amino acids • Uses glucose derivatives (glycolysis, TCA) • N sources often other aa • Describe important cofactors: • PLP (from Vitamin B6) for transaminations • FH4 (tetrahydrofolate) for 1C; • BH4 (tetrahydrobiopterin) for hydroxylation • (Phe → Tyr) • Explain general regulation of amino acid synthesis (feedback inhibition, transcription inhibition) • Degradation of aa often distinct from synthesis path

  2. Overview synthesis of nonessential amino acids • Overview synthesis of nonessential amino acids: • Met donates the S to Cys • C skeletons come from glucose, glycolysis, TCA compounds • Aa that can be synthesized are often used for other N cmpds: • Gly → purine, pyrimidine • Asp → purine, pyrimidine • Gln → neurotransmitter Fig. 39.1*

  3. Overview Degradation of amino acids • Overview: degradation of amino acids: • Gluconeogenic: Pyruvate, TCA intermediates • B. Ketogenic: Acetyl CoA, ketone bodies Fig. 2

  4. Some genetic disorders of amino acid metabolism • Degradation • path enzyme disease symptoms • Phe phe hydroxylase (PAH) PKU classic mental retardation • homogentisate oxidase alcaptonuria black urine, arthritis • Tyr fumarylacetoacetate hydrolase tyrosinemia I liver failure, death • tyrosine aminotransferase tyrosinemia II neurological • Met cystathionase cystathionuria benign • cystathionine b-synthase homocystinemia cardiovascular, • neurological • Gly glycine transaminase oxaluria type 1 renal failure • (Gly → oxalate) Ca-oxalate stones

  5. Metabolism of Phe/Tyr • Phe and Tyr: • PKU from absence PAH (autosomal recessive); 1/104 births; all babies tested; • give special diet of low Phe (essential aa) • High Phe in blood → neurological • Tyr is made from Phe • various defects in degradation • neurological, liver failure Fig. 39.15

  6. Cysteine metabolism • Cysteine metabolism: • C, N from Ser, S from Met • Met donates S to Cys via Homocys • Removal of –CH3 • Cystathionine precursor of Cys • Feedback regulation of synthase • Adjust for dietary Cys • Lack of synthase → homocyst(e)inemia Figs. 39.6 Cys

More Related