UNIT 1 UNE CHEM 1005 Test
Questions with Actual Complete
Answers 2026 Updated.
Hemoglobin binds oxygen with a greater affinity in the: - Answer R state
Hemoglobin bound to heme is termed a holoprotein. The heme or porphoryin ring is required
for oxygen binding and it is termed a: - Answer prosthetic group
Alpha helices and beta sheets are primarily stabilized by: - Answer H bonding
Ligases are a class of enzymes characterized by their ability to: - Answer synthesize bonds
between carbon atoms and an additional atom that is involved in the cleavage of a high energy
bond.
An enzyme inhibitor that increases the Km but does not change the Vmax is classified as: -
Answer competitive inhibitor
Cleavage of fructose 1, 6 bisphosphate to dihydroxyacetone and glyceraldehyde 3-phosphate is
achieved by what class of enzymes: - Answer lyase
Enzymes reduce the activation energy for a reaction. All enzymes do this by: - Answer
providing an active site most complementary the transition state, Enzymes help to reduce the
activation energy of a reaction by stabilizing high energy intermediates. By have a flexible active
site that is highly complementary to the transition state of a substrate this is most readily
achieved.
The activity of an enzyme is increased when the enzyme is phosphorylated on an exposed
tyrosine residue. Phosphorylation of this amino acid is classified as which of the following? -
Answer covalent modification, Phosphorylation is a covlanet modification to an enzyme that
can increase or decrease the activity of an enzyme.
Under low energy conditions, AMP will bind to phosphofructokinase I and glycogen
phosphorylase. This is an example of which of the follow types of enzyme regulation? - Answer
allosteric activation
Which of the following is an example of enzyme regulation through covalent modification? -
Answer Phosphorylation of muscle glycogen phosphorylase
, Movement of ammonia from an amino acid to an alpha-keto acid involves a family of enzymes
best categorized as: - Answer Transferases
An alpha-helical arrangement of amino acids is considered to be part of what level of protein
structure? - Answer secondary structure of the protein
An example of enzyme activation by cleavage is best illustrated by which of the following? -
Answer activation of chymotrypsinogen to chymotrypsin
Coenzymes are complex nonprotein molecules that participate in catalysis by providing
functional groups that form a covalent intermediate between the enzyme and the substrate.
Which of the following is an example of a coenzyme that participates in an activation-transfer
reaction? - Answer Thiamaine pyrophosphate (TPP)
Motifs are common structural elements that retain a particular function within the protien.
Which of the following is an example of a protein motif? - Answer An arrangment of β-
strands connected by α - helicies (βαβαβ)
What is an allosteric activator? - Answer a. binds and puts active site in optimal configuration
which
favors substrate binding, higher efficiency
b. noncovalent, so reversible
c. also dependent on enzyme concentration
What is an allosteric inhibitor? - Answer a. binds to enzyme and changes shape of active site
so substrate cannot bind and enzyme is turned off
b. binding through noncovalent interactions so are reversible
c. whether or not they bind to enzyme depends on concentration
d. the mechanism behind feedback inhibition
Competitive inhibitors? - Answer Compete with substrate for binding at enzyme's substrate
recognition site. This increases Km because it increases the concentration of substrate needed
to saturate the enzyme, but no change to Vmax.
Noncompetitive inhibitor - Answer Does not compete with substrate for binding at the
enzyme's substrate recognition site. Lowers concentration of active enzyme so Vmax decreases,
but no change to Km.
Protein kinases phosphorylate proteins only at a certain hydroxyl groups on amino acid side
chains. All contain side chain hydroxyl groups: - Answer Serine, Threonine, Tyrosine
Questions with Actual Complete
Answers 2026 Updated.
Hemoglobin binds oxygen with a greater affinity in the: - Answer R state
Hemoglobin bound to heme is termed a holoprotein. The heme or porphoryin ring is required
for oxygen binding and it is termed a: - Answer prosthetic group
Alpha helices and beta sheets are primarily stabilized by: - Answer H bonding
Ligases are a class of enzymes characterized by their ability to: - Answer synthesize bonds
between carbon atoms and an additional atom that is involved in the cleavage of a high energy
bond.
An enzyme inhibitor that increases the Km but does not change the Vmax is classified as: -
Answer competitive inhibitor
Cleavage of fructose 1, 6 bisphosphate to dihydroxyacetone and glyceraldehyde 3-phosphate is
achieved by what class of enzymes: - Answer lyase
Enzymes reduce the activation energy for a reaction. All enzymes do this by: - Answer
providing an active site most complementary the transition state, Enzymes help to reduce the
activation energy of a reaction by stabilizing high energy intermediates. By have a flexible active
site that is highly complementary to the transition state of a substrate this is most readily
achieved.
The activity of an enzyme is increased when the enzyme is phosphorylated on an exposed
tyrosine residue. Phosphorylation of this amino acid is classified as which of the following? -
Answer covalent modification, Phosphorylation is a covlanet modification to an enzyme that
can increase or decrease the activity of an enzyme.
Under low energy conditions, AMP will bind to phosphofructokinase I and glycogen
phosphorylase. This is an example of which of the follow types of enzyme regulation? - Answer
allosteric activation
Which of the following is an example of enzyme regulation through covalent modification? -
Answer Phosphorylation of muscle glycogen phosphorylase
, Movement of ammonia from an amino acid to an alpha-keto acid involves a family of enzymes
best categorized as: - Answer Transferases
An alpha-helical arrangement of amino acids is considered to be part of what level of protein
structure? - Answer secondary structure of the protein
An example of enzyme activation by cleavage is best illustrated by which of the following? -
Answer activation of chymotrypsinogen to chymotrypsin
Coenzymes are complex nonprotein molecules that participate in catalysis by providing
functional groups that form a covalent intermediate between the enzyme and the substrate.
Which of the following is an example of a coenzyme that participates in an activation-transfer
reaction? - Answer Thiamaine pyrophosphate (TPP)
Motifs are common structural elements that retain a particular function within the protien.
Which of the following is an example of a protein motif? - Answer An arrangment of β-
strands connected by α - helicies (βαβαβ)
What is an allosteric activator? - Answer a. binds and puts active site in optimal configuration
which
favors substrate binding, higher efficiency
b. noncovalent, so reversible
c. also dependent on enzyme concentration
What is an allosteric inhibitor? - Answer a. binds to enzyme and changes shape of active site
so substrate cannot bind and enzyme is turned off
b. binding through noncovalent interactions so are reversible
c. whether or not they bind to enzyme depends on concentration
d. the mechanism behind feedback inhibition
Competitive inhibitors? - Answer Compete with substrate for binding at enzyme's substrate
recognition site. This increases Km because it increases the concentration of substrate needed
to saturate the enzyme, but no change to Vmax.
Noncompetitive inhibitor - Answer Does not compete with substrate for binding at the
enzyme's substrate recognition site. Lowers concentration of active enzyme so Vmax decreases,
but no change to Km.
Protein kinases phosphorylate proteins only at a certain hydroxyl groups on amino acid side
chains. All contain side chain hydroxyl groups: - Answer Serine, Threonine, Tyrosine
