BIOC192 Lecture 31 - Oxidation of Amino Acids Flashcards
what 2 things does deamination generate?
1) a carbon skeleton
2) a free amino group
what can a carbon skeleton be used for?
can be used for energy capture in catabolic reactions
what is the result of the production of a free amino group?
the free amino group is generally excreted
what ways can deamination occur?
- some amino acids can be deaminated by releasing their amino groups to solution
- transamination. reaction where the amino acid is deaminated by transferring their amino acid to a keto acid
what are transamination reactions catalysed by?
catalysed by aminotransferase enzymes (transaminases)
what is required for transamination reactions?
a co-enzyme called pyridoxal phosphate
what is pyridoxal phosphate derived from?
derived from vitamin B6
what does pyridoxal phosphate carry?
carries the amino group (from the amino acid to the keto acid)
what are the forms of pyridoxal phosphate and how do they differ in amino acid groups?
1) pyridoxal phosphate (no amino group)
2) pyridoxamine phosphate (with amino group)
how many steps are there in there in the transamination reaction?
involves 2 steps
what occurs in the 1st step of transamination?
amino group is transferred from the amino acid to the pyridoxal phosphate to create pyridoxamine phosphate
what occurs in the 2nd step of transamination?
amino group is transferred from pyridoxamine phosphate to the keto acid
what are the amino acid/keto acid pairs in metabolism?
glutamate –> alpha-ketoglutarate
aspartate –> oxaloacetate
alanine –> pyruvate
can keto acids feed into the metabolic pathways?
yes either directly into pyruvate and actyl-CoA or in the citric acid cycle
what are the 2 ways keto acids can enter metabolic pathways?
1) some keto acids can enter directly
2) some keto acids require modification first
what is the relationship between transamination reactions and nitrogen?
transamination reactions are also required to remove excess nitrogen via the liver
what is oxidative phosphorylation?
the coupled process of electron transport through the electron transport chain (ETC) and the phosphorylation of ADP to ATP by ATP-synthase
how are the processes of oxidative phosphorylation coupled?
coupled by a proton gradient made by the electron transport chain
what uses the proton gradient?
ATP-synthase
where is the electron transport transport chain located?
located in the inner membrane of the mitochondria
