22- Power Sources and Metabolism Flashcards
What are the three major uses of Amino Acids?
To prodce metabolic energy
To make protein
To make other molecules
What is meant by glucogenic amino acid?
The carbon skeletons are degraded to pyruvate or TCA cycle intermediates, which are precursors for glucose synthesis
What is meant by ketogenic amino acid?
Carbon skeleton degraded to acetyl-CoA or acetoacetate.
Ketogenic AA can be catabolised for energy in the TCA cycle or converted to ketone or fatty acids
CANNOT be converted to gluscose
What is phenylketonuria (PKU)?
Caused by problems with phenylalanine metabolism
What is the role of the enzyme glutamate dehdrogensae?
Facilitates the conversion of nitrogen to ammonium
What is step 1 of the urea cycle? and where does it occur?
check if we need to know the equations
Ammonium is used to synthesise carbamoyl phosphate
Occurs in the mitochondria
Where does the urea cycle occur?
Mainly in the liver and to a lesser extend the kidneys
What are the reactants of step 1?
NH4+ +CO2 +2ATP
What enzyme is used in step 1 of the urea cycle?
Carbamoyl phosphate synthase
CPS
What are the products of step 1 of urea cycle?
Carbamoyl Phosphate + 2 ADP + Pi
What are the reactants of step 2 of the urea cycle?
Carbamoyl phosphate and ornithine
What are the products of step 2 of the urea cycle
Citrulline and Pi
What enzyme is used in step 2 of the urea cycle?
Ornithine Transcarbamoylase
Where does step 2 of the urea cycle occur?
Mitochondria
What are the reactants of step 3?
Citrulline + Aspartate + ATP
What enzyme is used in step 3 of the urea cycle?
Argininosuccinate Synthetase
What are the products of step 3 of the urea cycle?
Argininosuccinate
+ AMP + PPi
Where does step 3 of the urea cycle occur?
Cytosol
What are the reactants of step 4?
Argininosuccinate
What enzyme is used in step 4 of the urea cycle?
Argininosuccinate Lyase
What are the products of step 4 of the urea cycle?
Arginine + Fumarate
Where does step 4 of the urea cycle occur?
Cytosol
What are the reactants of step 5?
Arginine + H2O
What enzyme is used in step 5 of the urea cycle?
Arginase
What are the products of step 5 of the urea cycle?
Ornithine + Urea
Where does step 5 of the urea cycle occur?
Cytosol
What happens if there is a disorder in the urea cycle?
Results in very high circulating ammonium levels
What type of bases are A & G and what structure do they have?
Purines with a 2 ring structure
What type of bases are C & T and what structure do they have?
Pyramidines with a single ring structure
What is a nucleotide?
Base and 5 carbon sugar and a phosphate group
What is a clinical condition caused by increased levels of uric acid?
Gout due to diet
Describe purine metabolism?
Adenosine and guanosine becomes adenine and guanine which combine to form xanthine xanthine oxidase will then make in form uric acid
