Chapter 18 Flashcards
Most amino acids are metabolize in the __________
Liver
_____________ participates in the transfer of alpha-amino groups to alpha-ketoglutarate
Pyridoxal phosphate
In the first step of catabolism of an L amino acids is the removal of the amino group which is catalyzed by enzyme called ______________
Aminotransferase
In the ______________ reaction of the removal of the amino acid, the alpha amino group is transferred to the alpha carbon atom of alpha-ketoglutarate, which formed an alpha alpha keto acid in the process
Transamination
The purpose of the transamination reactioon is to collect the amino group from many different amino acid in the form of ______________ which then acts as an amino group donor for other pathways or exertion pathways that eliminate amine (NH3+)
Glutamate
When an amino acid & ketoglutarate react they exchange the amino group & the_____________ (so the amino acid becomes the keto acid & ketoglutarate turns into glutamate (transamination reaction)
keto group
In many aminotransferase reactions, alpha ketoglutarate is the amino group __________ (all aminotransferase pyridoxal phosphate (PLP) as a cofactor) (or prosthetic group)
Pyridoxal phosphate
The enzyme are named for the aminotransferase based on the ____________ amino acid being used
Specific (alanine aminotransferase)
____________ releases its amino group ammonia in the liver
Glutamate
In an a transamination reaction the amino group & keto group ___________
Switches
Glutamate is transported from the cytosol into mitochondria where it undergoes oxidative deamination which is catalyzed by__________________
L-glutamate dehydrogenase (Glu-dHase) (uses NAD+ or NADP+ as a cofactor)
The combined action of an aminotransferase & glutamate dehydrogenase is referred to as __________________
Transdeamination
Glutamine transport _______________ in the bloodstream
ammonia
___________ is critical to intracellular amino group metabolism because its converted to glutamine
Glutamate
The free amino produced with glutamate to yield glutamine is catalyzed by ___________________
Glutamine synthase
Excess ammonia in tissues is added to glutamate to form glutamine a process catalyzed by________________ & after transport in the bloodstream enters the liver & NH4+ is released in mitochondria by the enzyme ____________
glutamine synthase, glutaminase
The NH4+ is released in the mitochondria where the enzyme glutamine synthase converts glutamine to glutamate & NH4+ is transported in the blood to the liver where it’ll be disposed of by ____________
Urea synthesis
______________ transports am onia from skeletal muscles to the liver
Alanine
Alanine transports amino group to the liver via the ________________
glucose alanine cycle
The glucose alanine cycle allows the energetic burden of _________________ to be imposed on the liver rather than the muscle & all available ATP in the muscle is devoted to muscle contraction
gluconeogenesis
All the __________ in our body gets trapped by ketoglutarate & ketoglutarate is converted to glutamate with the amine
amine (NH3)
The cycle between ketoglutarate turning into _________________ & glutamate going through its reaction to release the amine & convert back to ketoglutarate is constant
glutamate
Asperate will react to form ______________ as its keto acid
Oxalacetate
Glu, Gln will react to form _________________ as its keto acid
alpha-ketoglutarate
Alanine will react to form _______________ as its keto acid
Pyruvate
The enzyme responsible for removing the amino off the glutamate to form ketoglutarate is _________________
Glu-dHase (glutamate dehydrogenase)
In the cycle reaction between _______ _________& glutamate the glutamate turns back into ketoglutarate by reacting with NADP+ to make NAPH which then make an intermediate & that intermediate reacts with water to release the amine (NH4-) to form ketoglutarate (This reaction is catalyzed by the Glu-dHase enzyme)
ketoglutarate
