ENZMES : DAILY PRACTICE PAPER (DPP) BY TEACHINGCARE.COM
- Choose the incorrect statement w.r.t. enzymes
- Almost all enzymes are proteins.
- Some RNA molecules that behave
like enzymes are called ribozymes.
- An enzyme like any protein has a primary structure
- An enzyme is consumed during the catalysis of its reaction
- When you look at a tertiary structure, the backbone of the protein chain folds
upon itself, the chain criss-crosses itself and hence, many crevices or
pockets are made. One such pocket where the actual catalytic reaction takes place is called the
- active site.
- Reactive site
- Responsive sites
- Carrier site
3.Choose the incorrect statement w.r.t. enzymes and inorganic catalysts
- Inorganic catalysts work efficiently at high temperatures
and high pressures,
- enzymes usually get damaged at high temperatures
(say above 40°C).
- enzymes isolated from organisms who normally
live under extremely high temperatures (e.g., hot vents and sulphur
springs) are unstable
- enzymes isolated from thermophilic organisms retain their catalytic power even at high
temperatures (upto 80°-90°C).
4.Choose the correct statements w.r.t. rates of chemical reactions
a.Rates of physical and chemical processes are influenced by temperature among other
b.A general rule of thumb is that rate doubles or decreases by half for every 10°C change in either direction.
c.Catalysed reactions proceed at
rates vastly higher than that of uncatalysed ones.
d.When enzyme catalysed reactions are observed, the rate would be vastly higher than the same but
- a and b only
- a, b and c only
- b, c and d only
- a, b, c and d
5.The activity of an enzyme can be affected by a change in the conditions
which can alter the tertiary structure of the protein. These include
- change in substrate concentration or binding of specific
chemicals that regulate its activity.
- a only
- b only
- c only
- a,b, c
- Effect of change in concentration of substrate on enzyme activity is best shown by the graph
7.Choose the incorrect statement w.r.t. temperature and its effects on enzymes
- Enzymes generally function in a narrow range of temperature.
- Each enzyme shows its highest activity at a particular temperature called the optimum temperature .
- Low temperature makes the enzyme to remain in a permanently inactive state
- high temperature destroys enzymatic activity because proteins are
denatured by heat.