Biochem- AA metabolism
Terms
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- in order to make protein you need ALL amino acids T/F
- T
- what are essential amino acids
- aa we can't synthesize
- negative nitrogen balance
- excreting more nitrogen than taking in (e.g., Kwashikor's disease)
- positive nitrogen balance
- taking in more nitrogen than excreting
- this amino acid is essential only in growth phases
- histadine
-
name the tca cycle intermediate that produces:
1)FA
2)AA synthesis (neurotransmitters)
3)heme synthesis
4)gluconeogenesis
5)amino acids -
1)citrate
2)alpha ketogluterate
3)succinyl coA
4)malate
5)oxaloacetate - glycogenic
- can become glucose or glycogen
- ketogenic
- can become ketone bodies
- leucine is the only strictly ___________ amino acid.
- ketogenic. All others are glycogenic or both
-
Alanine is converted to pyruvate via what enzyme?
How is this reaction classified? -
ALANINE TRANSAMINASE ENZYME(serum glutamate pyruvate transaminase)
Transaminase rxn -
Aspartate is converted to oxaloacetate by using what?
How is this reaction classified? -
alpha ketogluterate
glutamate
Transaminase rxn -
Glutamate is converted to glutamine via what enzyme
The reverse happens with what enzyme? -
glutamine synthase enzyme
glutaminase - how do you diagnosse cystinurea?
- assay urine for lycine, ornithine, arginine
- ______ bonds in homocystein molecules can lead to DVT, thrombosis, & hypercoagulation in homocystein urea
- disulfide
- what enzyme is involved in homosystein urea
- cystathione synthase
- cystathione synthase is a _____ containing enzyme, meaning _____ vitamen deficiencis may effect it.
- PLP, vB6
- describe enzyme and cofactors involved in cystathionin urea
- Cystathionin urea involves the cystathion lyase enzyme it is a PLP containing enzyme (B6)
- What enzymes are fed into the proprionic acid pathway
-
Valine
or
Methionine
Isoleucine
Threonine
(VoMIT) - in PAP, Homosystein comes from _______
- methionine (homosystein + methyl)
-
Maple Syrup Urine Disease
1)enzyme
2)AA metabolism affected -
1)Branch chain alpha ketoacid dehydrogenase
2)leucine, isoleucine, valine -
PKU
1)enzyme
2)problem
3)sweetener to avoid -
1)phenalalanine hydroxylase
2)phenyl ketones build up in blood stream
3) aspartame - phenyl alanine is transaminated to produce which phenyl ketones in PKU?
- phenyllactate & phenyl pyruvate
-
Alkaptonuria
1)enzyme
2)AA metabolism involved
3)clinical signs & symptoms -
1)homogentisate dioxygenase
2)phenylalanine & tyrosine
3)Dark urine, ocronosis (darkening of jts), & arthritis -
Alkaptonurea
1)enzyme
2)pathway
2)clinical signs -
1)homogentisate oxidase
2)AA metabolism
3)Dark Urine, Ochronosis:Darkening of the joints & Arthritis - nongenetic causes of homocysteine urea
- deficiency of B6 (folate) & B12
- enzymes that use B12 as cofactor (give pathway as well)
-
1)Homocysteine Methyltransferase (methionine synthase)
2)Methmalonyl-CoA Mutase (proponyl CoA pathway) - what is build-up of methmalonyl CoA is called and what is diagnostic for
-
methmalonyl urea
B12 deficiency - Dihydrofolate reductase-
- converts Folate(F)to Dihydrofolate(FH2)to etrahydrofolate(FH4) by methyl transferase. Important in making DNA from RNA
- thymadylate synthase
-
takes dUMP to dTMP, N5,N10 methylene FH4 is carrier of methyl group
-inhibited by 5-FU (chemotherapy) - dihydrofolate reductase
-
takes FH2 to FH4
-inhibited by methotrexate (chemotherapy) - sx of methotrexate similar to _______
- folate
- SAM-- what does it do and give example
-
used directly for methyllations
(e.g., Norepinephrine -- epinephrine;Nucleotides -- methalinated Rxns) - Homocysteine Methyltransferase (methionine synthase)
- key enzyme in methylation cycle. Converts homocystein to methionine. Uses B12 as a cofactor and ALSO B6 which interacts w/ B12
-
Maple syrup Urine disease
1)enzyme
2)clinical symptoms -
1)branched chain keto acid dihydrogenase
2)urine has oder of maple syrup,mental retardation,abnormal mm tone,ketosis, coma, death -
PKU
1)enzyme
2)clinical symptoms -
1)phenylalenine hydroxylase
2)mental retardation, microcephaly, diet important, musty odor, - causes of homocystein urea
-
Vit B12 blockage
Vit B6
Genetic disorder - differential diagnosis of homocystein urea
-
B12 deficiency you will also see associated methomalonic acid urea.
If not B12 give B6 if doesn't recover then genetic - How does B12 deficiency induce B6 deficiency
- Folate trap. We need B12 as a cofactor for homocystein methyl transferase. HMT is necessary to recylce folate from it's inactivated reduced methylated form (methylated THF) to it's active form THF.
- megablastic anemia check for
- homoceistein urea
- Megablastic anemia due to folate deficiency:
-
Homocystinurea
Developes 3-4 months
Risk factors for deficiency:
-pregnancy
-alcoholism
-severe malnutrition - Megaloblastic anemia due to Vit B12 (Cobalamin) deficiency
-
Progressive peripheral neuropathy*
Homocystinemia w/ risk for cardiovascular disease
Methylmalonic aciduria*
Deficiency develops in years
Risk factors:
-Pernicious anemia
-gastric resection
-chronic pancreatitis
-severe malnutrition
-vegan
-infection w/ D. latum - Pernicious anemia
- Subset of Megaloblastic anemia. Due to lack of intrinsic factor inhibiting B12. Will have w/ vit B12 deficiency.