Biochemistry Test 3 Sapling Review

epimers, diastereomers, anomers
What terms describe the relationship between a-D-glucose and B-D-glucose
epimers, diastereomers
What terms describe the relationship between a-D-glucose and a-D-mannose?
enantiomers
What terms describe the relationship between a-D-glucose and a-L-glucose
mannose, maltose, fructose
Which of the following sugars show mutarotation?
uronic acid
Oxidation of carbon 6 of a hexose to the level of a carboxylic acid
aldonic acid
oxidation of the aldehyde carbon of a sugar to the level of a carboxylic acid
aldonic acid
Gluconic acid is an example of this type of sugar derivative
amino sugar
Muramic acid is an example of this type of sugar derivative
deoxy sugar
fucose is an example of this type of sugar derivative
disaccharides
lactose and trehalose are ________
non-reducing
trehalose is a _____ sugar
O-glycosidic bond
lactose and trehalose are joined by a ______
free anomeric carbon
A reducing sugar must have a
chitin
consists of N-acetylglucosamine residues
starch
a storage form of fuel for plant cells
glycogen
functions in fuel storage in animal cells
chitin
provides structural support for animals, most conspicuously in the exoskeletons of arthropods
glycogen
the storage form of glucose in animals
cellulose
provides structural support for plants
starch
made up of two glucose polysaccharides – amylose and amylopectin
homoglycans
starch, glycogen, cellulose, and chitin are examples of
starch
plant polysaccharide that is easily digested by humans
N-acetylglucosamine and uronic acid
Possible components of glycosaminoglycans
heteroglycans
Glycosaminoglycans are _______
glycosaminoglycans
chondroitin sulfate and keratan sulfate are examples of
recognition of specific oligosaccharide structures
function of lectins
sugar code
Structural variability in oligosaccharides specifying interactions at cell surfaces.
chondroitin sulfate
Polymer of D-Glucuronic acid (GlcA) and N-acetylgalactosamine (GalNAc4S)with β(1 3) linkages, found in ligaments and the walls of the aorta.
sialic acid
Lectin molecules specifically bind to oligosaccharide molecules in absence of this terminal residue.
peptidoglycan
Contains β(1 4) glycosidic bond between N-acetylglucosamine and N-acetylmuramic acid.
heparin sulfate
L-iduronic acid (IdoA2S) and glucosamine (GlcNS3S6S) α(1 4), found in mast cells.
keratan sulfate
Polymer of galactose and N-acetylglucosamine with β(1 4) linkages, found in nails and hooves.
glucose+2ADP+2Pi+2NAD+ -> 2pyruvate+2ATP+2NADH
net equation of glycolysis
nonspontaneous
reaction 1 of the first step of glycolysis is :
glucose+ATP -> glucose-6-phosphate+ADP
Net chemical equation of Step 1 of glycolysis
step 6
which step of glycolysis is a redox reaction?
1,3,7,10
these steps are catalyzed by a transferase
2,5,8
these steps are catalyzed by an isomerase
4,9
these steps are catalyzed by a lyase
hexokinase, phosphohexose isomerase, phosphofructokinase, aldolase, triosephosphate isomerase, triose phosphate dehydrogenase, phosphoglycerate kinase, phosphoglycerate mutase, enolase, pyruvate kinase
10 enzymes of glycolysis
G6P
in the first reaction of glycolysis, glucose is converted to _______. The phosphate comes from ATP
3
the main control point of glycolysis
ATP, citrate
negative inhibitors of step 3 of glycolysis
ADP, AMP
positive effectors that activate phosphofructokinase-1
increase
loss of allosteric binding site for ATP in pyruvate kinase would _____ the rate of glycolysis
increase
loss of regulatory binding site for ATP in phosphofructokinase would ______ the rate of glycolysis
decrease
loss of allosteric binding site for AMP in phosphofructokinase would _____ the rate of glycolysis
decrease
loss of binding site for fructose, 1,6- bisphosphate in pyruvate kinase would _____ the rate of glycolysis
glucokinase
plays an important role in liver regulation of blood glucose level, not sensitive to inhibition by G6P
hexokinase
when blood glucose is low, will cause cells to trap glucose by phosphorylation
oxaloacetate
pyruvate is dephosphorylated by pyruvate carboxylase to become
2pyruvate+2NADH+4ATP+2GTP -> glucose+2NAD++4ADP+2GDP+6Pi
net equation of gluconeogenesis
8
Which step of gluconeogenesis is the main negative control point?
insulin, AMP, fructose-2,6-bisphosphate
Which inhibits the enzyme for step 8 in gluconeogenesis
glycolysis
activation of PFK-2 activates ______
gluconeogenesis
inhibition of PFK-2 activates
gluconeogenesis
increased levels of cAMP activates ______
gluconeogenesis
increased glucagon levels activates ______
glycolysis
Increased levels of fructose 2,6-bisphosphate activates
G6P
the substrate for the pentose phosphate pathway
NADP+/NADPH
Which molecule controls the rate of the pentose phosphate pathway
glucose-6-phosphate dehydrogenase
Enxyme that catalyzes the reaction influenced by NADP+/NADPH
G6P
Galactose derivative that can enter glycolysis
DHAP and G3P
Fructose derivative that can enter glycolysis
acid-base catalysis
a proton is transferred between enzyme and substrate
acid-base catalysis
may use amino acids such as aspartate or lysine for protonation or proton abstraction
covalent catalysis
a covalent bond forms between enzyme and substrate
covalent catalysis
uses a nucleophilic functional group
covalent catalysis
two-part catalytic process
metal ion catalysis
catalyst may participate in redox reactions by changes in the oxidation state
catalyst
retains its original form after reaction occurs
allosteric enzymes
interconvert between a more active form and less active form
reversible competitive
inhibitor structure resembles substrate structure
reversible competitive
inhibitor binds noncovalently at active site
reversible noncompetitive
inhibitor binds noncovalently at site other than active site
irreversible
inhibitor binds covlaenty and permanentyl at site other than active site
competitive inhibitor
structurally similar to substrate
competitive inhibitor
when present, vMAX of enzyme is unaffected
competitive inhibitor
prevents substrate from binding enzyme
uncompetitive inhibitor
when present, Km of enzyme will decrease
uncompetitive inhibitor
binds enzyme-substrate complex only
mixed inhibitor
binds either enzyme or enzyme-substrate complex
mixed inhibitor
when present, Km of enzyme will either increase or decrease
irreversible inhibition
inhibitor may permanently modify an enzyme
irreversible inhibition
DIPF permanently modifies the hydroxyl group of a Ser residue at the active site
competitive inhibition
binding by the inhibitor increases Km but not Vmax
mixed inhibition
binding by the inhibitor increases Km but decreases Vmax
coenzyme A
forms part of the acetyl-SCoA, which is part of the citric acid cycle
coenzyme A
derived from the vitamin pantothenic acid
NAD+
derived from the vitamin nicotinamide
NAD+
accepts two electrons and one proton when it is reduced
FAD
derived from the vitamin riboflavin
FAD
accepts two hydrogen atoms when it is reduced

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