The answer is d because i had the same problem yesterday in biology
Ans.
Tuberculosis (TB) is a bacterial infection that affects mainly respiratory tract and can be transmitted from one to another person through contaminated air. The causative agent of tuberculosis, <em>Mycobacterium tuberculosis</em> has developed resistance against many antibiotics, such as rifampin and isoniazid, which is known as tuberculosis drug resistance.
If a person infected with TB shows drug resistance against some TB drugs, 'doctors should give other TB drugs to that person, even if these drugs show less effect than common drugs'. This is because these drugs can prevent or kill the bacterium more effectively than the common drugs for which, bacterium is resistance.
Answer: a) substrate and cofactors b) covalent modification
Explanation:
Metabolic pathways involve all the chemical processes takes place in the enviornment or in an organisms.The metabolic pathways are controlled through the catalytic activities of enzymes.
The availability of enzyme is regulated by substrate and cofactors present in enzyme and enzyme activity is commonly regulated via covalent modification.
Enzymes are highly selective in nature and bind to a specific substarte only. The active site in enzyme binds with the substrate to form enzyme substrate complex. Coactors assist the enzyme activity, without cofactor enzyme can not perform its activity.
Hence enzyme availibility is regulated by substrate and cofactors regulates.
Covalent modifications regulates activity of enzyme as it involves addition and removal of chemical group to synthesis required protein. It can change the chemical properties of the site by targeting one or multiple amino acid.
Thus the correct answer is a) substrate and cofactors b) covalent modification
