Enzymes Flashcards
What catalyses 2ADP –> ATP + AMP
Adenylate kinase
Creatine Kinase
Creatine + ATP -> Creatine phosphate + ADP
What breaks down alpha 1-4 glycosidic bonds
Amylase
What breaks down alpha 1-6, 1-4 glycosidic bonds?
Amylopectin
What breaks down sucrose to glucose and fructose?
Sucrase
What breaks down lactose to galactose and glucose?
Lactase
What breaks down maltose to glucose and glucose?
Isomaltose (alpha 1-6)
What are the three enzymes regulated in glycolysis?
- Hexokinase/glucokinase
glucose to glucose-6-phosphate
allosteric (G6P) - Phosphofructokinase
Fructose-6-bisphosphate to fructose-1,6-bisphosphate
Allosteric (ATP down, insulin up)
inhibited: ATP, citrate, H+
Activated: AMP, fructose-2,6-bisphosphate
10: pyruvate kinase
Phosphoenolypyruvate to pyruvate
Covalent modification - high insulin dephosphorylation activates
All high energy signals, hormone regulation insulin:glucagon ratio
What enzymes catalyses pyruvate to lactate?
Lactate dehydrogenase
2pyruvate + 2NADH + 2H+ —-> 2lactate + 2NAD+
Reduces
What catalyses the oxidative carboxylation of glucose-6-phosphate to C5 sugar phosphates? In the pentose phosphate pathway
Glucose-6-phosphate dehydrogenase
6-phosphogluconate dehydrogenase
What breaks down fructose?
Fructose to fructose-1-phosphate, fructokinase
Fructose-1-phosphate to 2-glyceraldehyde-3-phosphate, aldolase
(Enters glycolysis)
What does pyruvate dehydrogenase catalyse?
Pyruvate to acetyl CoA
Allosterically: inhibited acetyl CoA, NADH, ATP
activated pyruvate, NAD+, ADP,
Covalent modification by insulin dephosphorylation activates
What enzymes is involved in the regulation of the TCA cycle?
Isocitrate dehydrogenase
What is the enzyme that generates ATP?
ATP synthetase
What enzyme breaks down lipids during digestion?
Pancreatic lipase
What enzyme is responsible for lipolysis of adipose tissue?
Hormone sensitive lipase
Stimulated by glucagon, adrenalin, GH, cortisol, t4
Inhibited by insulin
What enzyme catalyses the phosphorylation of glycerol to glycerol phosphate?
Glycerol kinase
Requires ATP
First step in glycerol metabolism
Glycerol phosphate can be produced from dihydroxyacetone phosphate using NADH to NAD+
What enzymes is involved in the activation of fatty acids/linking to coenzyme A via the S atom forming a high energy of hydrolysis bond
Fatty acyl CoA synthase
Produced fatty acyl~CoA
What does CAT stand for?
Carnitine acyl transferase
CAT 2: carnitine to acyl carnitine
CAT 1: acyl carnitine to fatty acyl CoA
What enzyme catalyses the reaction acetyl CoA to HMG CoA?
Synthase
What catalyses HMG CoA of acetoacetate?
Lyase
Insulin/glucagon ratio if ratio falls lyase is activated
And vice versa
What enzyme catalyses HMG CoA to Mevalonate and then cholesterol
HMG CoA reductase
Insulin/glucagon ratio if ratio increases reductase stimulated
And vice versa
Enzymes involved in glycogenesis
Glucose to glucose-6-phosphate, glucokinase
Glucose-6-phosphate to glucose-1-P, phosphoglucmutase
Then forms UDP glucose
Then forms glycogen n+1 residues, glycogen synthase, branching enzyme
Enzymes involved in glycogenolysis
Forming glucose-1-P, glycogen phosphorylase, de branching enzyme
Then goes to glucose-6-P
Then glycolysis or glucose, glucose-6-phosphatase
