Metabolism, Enzymes Flashcards
Metabolism in Mitochondria
- Fatty acid oxidation (β-oxidation)
- Acetyl-CoA production
- TCA
- Oxidative phosphorylation
- ketogenesis
Cytoplasm metalbolism
- Protein synthesis (RER)
- Glycolysis
- Fatty acid synthesis
- Steroid synthesis (SER)
- Cholesterol synthesis
- HMP shunt
Metabolism in both cytoplasm and mitochondria
- Urea cycle
- Heme synthesis
- Gluconeogenesis
Kinases
Enzyme that uses ATP to add high energy phosphate group onto substrate
Phosphorylase
Enzyme that adds inorganic phosphate onto substrate without ATP
Dehydrogenase
Catalyzes oxidation-reduction reactions (pyruvate dehydrogenase)
Phosphatese
Enzyme that removes phosphate group from substrate
Hydroxylase
Adds hydroxyl group (-OH) onto substrate
Carboxylase
Transfer CO2 groups with the help of biotin
Site of HMP shunt
Cytoplasma
Mutase
Relocates a functional group within a molecule (vit b12 dependent methylmalonyl coa mutase)
Site of heme synthesis
Both cytoplasm and mitochondria
Acetyl coa production site
Mitochondria
Urea cycle site
Both cytoplasm and mitochondria
Gluconeogenesis
Both mitochondria and cytoplasm
Rate-determining enzyme of glycolysis
Phosphofructokinase-1 (PFK-1)
Rate-determining enzyme of gluconeogenesis
Fructose-1,6-bisphosphate
Rate-determining enzyme oF TCA
Isocitrate dehydrogenase
Rate-determining enzyme of glycogenesis
Glycogen synthase
Rate-determining enzyme of glycogenolysis
Glycogen phosphorylase
Rate-determining enzyme of HMP shunt
Glucose 6 phosphate dehydrogenase (G6PD)
Rate-determining enzyme of De novo pyrimidine synthesis
Carbamoyl phosphate synthetase II
Rate-determining enzyme of De novo purine synthesis
Glutamine - PRPP - amidotransferase
Rate-determining enzyme of Urea cycle
Carbamoyl phosphate synthetase I
Rate-determining enzyme of fatty acid synthesis
Acetyl coa carboxylase
Rate-determining enzyme of fatty acid oxidation
Carnitine acyltransferase I
Rate-determining enzyme of ketogenesis
HMG-Coa synthase
Rate-determining enzyme of Cholesterol synthesis
HMG-Coa reductase
Rte-determining enzymes of metabolic processes - means
Irreversible
Phosphorofructokinase regulators
AMP+ ATP- Citrate- Fructose-2,6-biphosphate +
Fructose 1.6 biphosphatase regulators
ATP+ AMP - citrate + Fructose 2.6 biphosphatate -
Isocitrate dehydrogenase reaction
Isocitrate to a-ketoglutarate
Fructose 1.6 biphosphatase reaction
Fructose 1.6 biphosphate to fructose 6 phosphate
Isocitrate dehydrogenase regulators
ADP+ ATP- NADH -
Glycogen phosphorylase regulators
- Epinephrin + 2. ATP - 3. Glucagon + 4. ADP+
- Insulin - 6. Glucose -6-phosphate -
Glycogen synthase regulators
- Glucose - phosphate +
- Insulin +
- Epinephrin -
- Glucagon -
- CORTISOL +
G6PD reaction
Glucose-6-phosphate to 6-phosphogluconolactone
G6PD regulators
NADP(+) +
NADPH -
Rate determining enzyme of De novo pyrimidine synthesis
Carbamoyl phosphate synthetase type II
Rate-determining enzyme of De novo purine synthesis
Glutamine - PRPP - amidotransferase
Glutamine - PRPP - amidotransferase regulators
AMP-
IMP-
GMP-
Carbamoyl phosphate synthetase I regulators
N-acetylgutamate +
HMG - coa reductase (cholesterol synthesis)
Insulin +
T4 +
Glucagon -
Cholesterol -
HMG reductase reaction
HMG-coa to mevalonate
Acetyl coa carboxylase regulators
Insulin +
Citrate +
Glicagon-
PALMITOYL - COA -
Carnitine acyltranserase I (fatty acid oxidation) regulator
Malonyl - coa -
ATP production
Malate-aspartate shuttle - 32 ATP
Glycerol-3-P shuttle - 30 ATP
Anaerobic glycolysis - 2 ATP
Arsenic/ATP production
Arsenic causes glycolysis to produce zero net ATP/replace Pi
ATP function
ATP hydrolysis can be couples to energetically unfavorable reactions
Malate-aspartate shuttle - tissue and ATP number
Heart and liver (32ATP)
Nicotinamides:
NAD+ (vitamin B3)
NADP+
Glycerol-3-phosphate shuttle - tissue and ATP number
Muscle (30ATP)
Flavin nucleotides
FAD+ (vitamin B2)
NAD+ is generally used in
Catabolic process to carry reducing equivalents away as NADH
NADPH is a product of
HMP shunt
NADPH is used in
- Anabolic process (steroids and fatty acid synthesis) as a supply of reducing equivalents
- Respiratory burst
- Cytochrome P-450
- Glutathiome reductase
ATP carries
Phosphorl groups
Coa , lipoamide carry
Acyl groups
NADH, NADPH, FADH2 carry
Electrons
Biotin carries
CO2
SAM carries
CH3 groups
Tetrahydrofolate carries
1-carbon unit
TPP carries
Aldehydes
First step of glycolysis
Phosphorylation of glucose (glucose -6-P)
First step for glycogen synthesis
Phosphorylation of glucose (glucose -6-P)
Glucose to glucose-6-P (enzyme)
Hexokinase or glucokinase depending on tissue.
Low glucose concentration - hexokinase
High glucose concentration - glucokinase
Hexokinase differ to glucokinase in
- Location 2. Km. 3. Vm. 4. Induction by insulin 5. Feedback inhibited by glucose-6-P 6. Gene mutation associated with maturity - onset diabetes of young
Hexokinase vs Glucokinase according to location
Hexokinase –> Most tissues bit not liver and cell pancreas
Glucokinase –> Liver and β cells of pancreas
Hexokinase vs Glucokinase according to Km
Lower –> hexokinase
Glucokinase –> higher
Hexokinase or glucokinase is induced by insulin
Glucokinase
Hexokinase vs Glucokinase according to Vmax
hexokinase –> Lower
Glucokinase –> higher
Hexokinase or glucokinase is feedback inhibited by glucose -6-P
Hexokinase
Hexokinase or glucokinase is associated with gene mutation of MODY
Glucokinase
Hexokinase or glucokinase is associated fructose -6-P negative regulation
Glucokinase
Hexokinase regulation
Glucose 6-P -
Glucokinase regulation
Fructose-6-P -