True or False
Enzymes act by lowering the activation energy.

True or False : Higher the activation energy of a reaction, faster is the reaction.

Enzyme pepsin acts in:

Assertion : The enthalpy of reaction remains constant in the presence of a catalyst. Reason : A catalyst participating in the reaction, forms different activated complex and lowers down the activation energy but the difference in energy of reactant and product remains the same.

True or False The lower the frequency of vibration, the higher is the pitch.

Activation energy for the acid catalysed hydrolysis of sucrose is 6.22 kJ mol^-1 , while the activation energy is only 2.15 kJ mol^-1 when hydrolysis is catalysed by the enzyme sucrase. Explain.

True or False : Phenol acts both as antiseptic and disinfectant.

Write True or False Nicotine is a the active chemical found in tobacco smoke which causes cancer.

True or False Leghaemoglobin has the ability to combine very rapidly with oxygen and thus act as oxygen carrier.

Write 'True' or 'False'. In quiescent centre cells are active.