WorksheetsAspartate Transcarbamoylase
Total questions: 23
Worksheet time: 13mins
Where does a non-substrate ,non-competitive regulatory molecule binds to an enzyme?
At active site
At allosteric site
Offsite
None of the above
Which of these is an allosteric enzyme?
Glutamine synthetase
Aspartate transcarbamoylase
All of the above
None of the above
Enzyme allosterically regulated often have two states known as which of the following combination of states?
The R and R states
The T and R states
The R and P states
The P and T states
Which forms do the relaxed and tense state takes
Inactive and active
Closed and open
Open and closed
Active and inactive
The catalysis of ATCase serve as the rate limiting step in
Purine biosynthesis
Lipid biosynthesis
Fattyacid biosynthesis
Pyrimidine biosynthesis
Do ATCase follow MM kinetics?
Strictly follows
Donot follow
Sometimes follows
None of the above
Binding of substrate to the catalytic subunit results in an equilibrium shift towards the
T state
R state
As the concentration of CTP increases ,rate of formation of N-carbamoyl aspartate will get
Doubled
Decreased
Constant
First increase then decrease
Binding of CTP to the regulatory subunit results in an equilibrium shift towards the
R state
T state
Tensed state
Relaxed state
The site to which the effector binds is termed as
Allosteric site
Regulatory site
Catalytic site
None of the above
As the active sites are occupied ,this shifts the equilibrium from
R state to T state
T state to R state
According to concerted model, the activity of ATCase is all or nothing; which means
It can only exist in T state
It can either exist in T state or R state
It can only exist in R state
It cannot exist in both T and R states
ATCase exist in two confirmations
Tense state and relaxed state
Taut state and relaxed state
Tense state and released state
Taut state and released state
Plotting rate of N - carbamoyl aspartate verses aspartate yields a
Closed curve
Sigmoidal curve
Hyperbolic curve
Transcendental curve
At low concentration of CTP, ATCase activity and rate of N-carbamoyl aspartate formation is
Low
High
Constant
Average
Cooperativity means
Two substrate binding to same active site
Binding to one site affects the binding affinity of other sites
Binding to one site donot affects other sites
None of the above
Cooperative behaviour implies that ATCase must consist of
Multiple subunit
Multiple activesites
Single subunit
Single active site
Which are the two types of multi- subunit structure in ATCase?
Catalytic dimer and regulatory trimer
Catalytic trimer and regulatory dimer
Catalytic tetramer and regulatory dimer
None of these
Inorder to probe the active site of ATCase ,which of the following was used?
Ciprofloxacin
Isoniazid
PALA
Cimetidin
In T state ,the enzyme has
Low affinity for substrate
Hight affinity for substrate
Which of these is a positive regulator of ATCase?
Acetyl CoA
CAP
ATP
UTP
Which of the following is a allosteric inhibitor of ATC?
ATP
CTP
UTP
Malonate
Which of these is not a property of allosteric enzymes?
There can be more than one allosteric site present in an enzyme molecule
They have a ability to respond to multiple condition, that influences the biological reaction
Velocity verses substrate concentration graph of allosteric enzyme is hyperbolic
Allosteric enzymes have a additional site other than active site
