Flashcards in Lecture 33 Deck (21):
1
What is the necessary cofactor of amino transferases?
pyridoxal phosphate (active form of B6)
2
What is the most commonly used pair in Amino Transferase reactions?
glutamate/alpha keto-glutarate
3
What does alanine become in a transaminase rxn? aspartate?
pyruvate, oxaloacetate
4
aminotransferases are found in practically all tissues - which two are the most and why?
muscle (glucoalanine cycle - for gluconeogenesis) and liver (urea cycle)
5
What enzyme is used to liberate NH4 from glutamine?
glutaminase
6
What enzyme is used to synthesize glutamine using NH4?
glutamine synthetase
7
What enzyme is used to tear NH4 off of glutamate (and possibly put it back on...)?
glutamate dehyrdogenase
8
Does intestinal bacteria produce NH4?
yes
9
What enzyme is used to convert other amino acids to glutamate?
aminotransferases
10
What enzyme is used to liberate NH4 from other amino acids?
amino acid oxidases
11
What type of reaction is the glutamate dehydrogenase reaction? What is utilized in formation of glutamate? What is utilized and released in opposite reaction (formation of alpha-ketoglutarate)?
- oxidation-reduction
- NH4 and NADPH
- NAD+ (NH4 released)
12
What is utilized in the glutamine synthetase reaction?
glutamate + ATP + NH4 = glutamine + ADP + Pi
13
What happens in the glutaminase rxn?
glutamine + H2O = glutamate + NH3
14
What must happen to amino acids if they are going to be used by anything but protein synthesis?
The amino group must be removed
15
What enzyme couples amino acids onto their specific tRNAs for protein synthesis?
-Amino acyl tRNA synthetase
16
What combines with the amino acids to produce Aminoacyl-AMP? What then replaces the AMP?
- ATP
- tRNA
17
What are the "sinks" for non-essential AA?
What are they used for? Arrows double or single sided?
- 3-phosphoglycerate, pyruvate, a-ketoglutarate, OAA
- glycolysis, gluconeogenesis, TCA cycle
- double
18
What are the sinks for Essential AA? Are arrows double or single?
- 3-phosphoglycerate, pyruvate, acetoacetate>acetyl CoA, a-ketobutyrate>propionyl CoA>succinyl CoA, fumarate
- single
19
What swaps amino groups from alpha-keto acids to amino acids? What carbons are the groups found on?
aminotransferases, C2
20
How many aminotransferases are there?
18
21