Different Compounds Flashcards
Synthase vs synthetase
Synthetase must cleave ATP to function
Synthase does not have to cleave ATP
Kinase
Plays a role in phosphorylation reactions
Porphyrins
Synthesized from succinyl-CoA and glycine
N and C atoms derived from glycine and acetate
Reaction catalysed by §-aminolevulinic acid synthase
- decarboxylation calalysed by PryP
condensation of §-aminolevulinate
catalysed by porphobilinogen synthase
Produces porphobilogen
Condensation of 4 porphobilogen molecules
Catalysed by porphobilogen deaminase
-eliminates amino group
Produces heme
Creatine
Nitrogenous organic acid that occurs naturally in vertebrates
Helps supply energy to cells (muscle) by forming ATP
-ergo essential nutrient
Human Blood contains 1% creatine
Biosynthesis of creatine
From arginine and glycine
1: condensation of arginine and glycine
- (arginine:glycine amidotransferase)
2: methylation of guanidoacetate
- (guanidoacetate-N-methyltransferase)—> SAM = methyl donor
Biosynthesis of creatine location
Liver and kidney
-transported to muscles through blood
Biosynthesis of SAM
Synthesised from ATP and methionine
-> methionine adenosyltransferase
Methyl carrier
Assists in transsulfuration
SAM ethylene synthesis enzymes
ACC synthase then ACC-oxidase
Volatile plant hormone that functions for seed germination and fruit ripening
SAM in polyamine synthesis
1: SAM decarboxylated by adenosylmethionine decarboxylase
- results in S-adenosylmethioninamine
2: S-adenosylmethionamine donates n-propylamine group
- results in polyamine
Bile salts
Steroids in bile with detergent properties
Oxidation of cholesterol by cytochrome P-450 enzymes in liver
Primary bile acids
Synthesised by liver
- cholic acids
- chenodeoxycholic acid
Secondary bile acids
Bacterial action in colon
- Lithocholic acid
- Dexycholic acid
Major bile salts in humans
Taurocholic acid
Glycocholic acid
Glycochenodeoxycholic acid
Taurochenodeoxycholic acid
Bile salt biosynthesis
Before acid secreted they are conjugated to glycine or taurine
-forms 8 possible conjugated bile acids
Lots of reactions, with a total of 14 enzymes in all that are involved in synthesis of bile salts
Pigments
Melanin - broad term for naturally occurring pigments
Produced in melanocytes
Tyrosinase is inhibited at normal body temp but active in cooler areas of skin at extremities (paws, tail, ears) and head
Pigment biosynthesis
Conversion of tyrosine to L-DOPA by tyrosinase
Inhibition of enzyme results in albinism
Oxidation of tyrosine followed by polymerization
Thyroid hormone
Iodine is condensed to tyrosine residues -takes place on thyroglobulin (MIT and DIT) Iodotyrosine molecules couple together -2 DIT = thyroxin (T4) - 1 MIT + 1 DIT = tri-iodothyronine (T3)
Catecholamines
Hormones (epinephrine, dopamine, norepinephrine)
Derived from tyrosine and phenylalanine
-phenylalanine hydroxylase
Catechol
Benzene ring with 2 hydroxyl side groups at C1 and C2
Creatine enzymes
Arginine:glycine amidotransferase
Creatine phosphokinase
Guanidinoacetate-N-methyltransferase (SAM IS DONOR)
SAM
S-adenosylmethionine
Polyamine function
Regulation in replication, transcription and translation
Leading to cell proliferation, differentiation and cell death
