biochemistry important stuff Flashcards
which enzyme class transfer H in redox reaction?
oxidoreductase- uses NAD+ and FAD+
dehydrogenase and reductase
which enzyme class transfers a functional group (2 reactants and 2 products)?
transferases
*kinases, phosphatases, transaminases
which enzyme class rearranges reactant (1 reactant and 1 product)?
isomerase
which enzyme class has H2O as the reactant? (hydrolysis)
hydrolase
*digestive enzymes- proteases, lipases, amylases
which enzyme class breaks C-C, C-S, C-N bonds without hydrolysis or redox?
lyase
decarboxylases- remove CO2
which enzyme class joins bonds between C&O, S or N and uses ATP?
ligases- add CO2
carboxylases- biotin
what is the rate limiting enzyme in a pathway?
allosteric regulation
when there is a high level of substrate that pushes a reaction to completion this is positive or negative allosteric regulation?
positive
when there is a high level of product that slows down the reaction this is a positive or negative allosteric regulation?
negative- feedback inhibition
what type of enzyme regulation adds or removes a phosphate group?
covalent modification
kinases and phosphatases
what is the term for gene expression to control enzyme concentration?
enzyme induction- slow
which monosaccharides are anomeric on C1?
glucose and galatose
which monosaccharides are anomeric on C2?
fructose
which pathway is stimulated by short bursts of exercise and burns out quickly?
ATP-PC
phosphocreatine system
creatine phosphate system
which enzyme and cofactor are needed for the ATP-PC pathway?
creatine kinase
magnesium
what is the primary reaction and product of glycolysis?
reactant- glucose
product- pyruvate and ATP
what are the regulatory enzymes of glycolysis?
hexokinase/glucokinase
pyruvate kinase
what is the key rate limiting enzyme of glycolysis?
phosphofructokinase
what are the fates of pyruvate from glycolysis?
alanine- glucose alanine cycle
lactate- fast glycolysis; Cori cycle also increased NADH (alcohol metabolism)
acetyl-CoA- glycolysis and krebs link
where can you find hexokinase and what does it do?
present in most tissues; locks glucose into the cell- committed; HIGH affinity for glucose (low Km)
where can you find glucokinase and what does it do?
liver and pancreas; stimulated by fructose and insulin; LOW affinity for glucose (high Km)
which cycle has the greatest production of ATP?
aerobic respiration/ cellular respiration
what is described as producing ATP using energy created by electron flow down the ETS to final electron acceptor, O2?
oxidative phosphorylation
phosphorylation of ADP to ATP
what are the end products of aerobic metabolism?
CO2
H20
ATP
how do our macronutrients get into the TCA cycle?
carbs: glycolysis
fats: B-oxidation
proteins: AA oxidation
what catalyzes the prep step of Krebs?
pyruvate dehydrogenase complex
what are the 5 cofactors of the TCA cycle?
NAD CoA FAD TTP lipoate
what inhibits Krebs?
Acetyl-CoA
NADH
high energy
covalent modification
what stimulates Krebs?
low energy decreased product epinephrine Ca2+ insulin
what is the main purpose of Krebs?
produce high energy products NADH and FADH2 to send to ETS
where does glyolysis take place?
cytosol
how do you get electrons from NADH produced in the cytosol into the mitochondria to donate electrons to ETS?
malate aspartate shuttle- electrons as NADH
glycerophosphate shuttle- electrons as FADH2
what enzyme is needed in the malate aspartate shuttle?
malate dehydrogenase
what enzyme is needed in the glycerophosphate shuttle?
glycerophosphate dehydrogenase
where is gluconeogenesis located?
cytosol and mitochondrial matrix
what stimulates and inhibits gluconeogenesis?
stimulate- glucagon
inhibit- insulin
what is the rate limiting step of gluconeogenesis?
fructose 1, 6-bisphosphatase overcome the PFK obstacle
what inhibits fructose-1,6-bisphosphatase and stimulate PFK?
increased AMP and fructose-2,6-bisphosphate
what stimulates fructose-1,6-bisphosphatase?
increased ATP and citrate
glycogenolysis is faster or slower than GNG?
faster but also burns out faster
what breaks a(1-4) bonds?
glycogen phosphorylase
what forms a(1-4) bonds?
glycogen synthase
what forms a(1-6) bonds?
glycosyl-(4:6)-transferase
what protein is required to initiate a new glycogen granule? what AA does it need?
glycogenin and it needs tyrosine
what is the regulatory enzyme of glycogenesis?
glycogen synthase
what pathway neither uses nor produces ATP?
pentose phosphate pathway/ hexose monophosphate pathway
the oxidative phase of PPP produces?
NADPH
the non-oxidative phase of PPP produces?
interconversion of sugars- ribose-5-phosphate
link to glycolysis making G-6-P available
what is the rate limiting step of PPP?
G-6-P dehydrogenase
what does NADPH provide electrons for?
fatty acid synthesis cholesterol synthesis nucleotide synthesis detox respiratory bursts antioxidant regeneration
PPP makes toxins water soluble for excretion by adding electrons and oxygen in a process called?
cytochrome P450 monooxygenase system in the liver
what are the cofactors for SOD and what does it produce?
zinc, copper, manganese
produces hydrogen peroxide
glutathione peroxidase needs what and does what?
needs selenium
eliminates hydrogen peroxide
what does catalase need and what does it do?
needs iron
eliminates hydrogen peroxide
neutrophils
found in cell peroxisomes
interconversion of sugars require what enzymes?
transketolase and transaldolase
