All of the following methods are used to culture viruses in a lab, except

A. viral infections: Cytopathic effects (CPEs) are structural and functional changes in host cells resulting from viral infections. Examples include cell rounding, syncytia formation, inclusion bodies, and cell lysis, all due to viral replication and interference with normal cellular processes.

B. protozoal infections: Protozoa can damage host tissues through invasion and toxin production, but they do not typically cause cytopathic effects as defined in virology.

C. fungal infections: Fungi may cause tissue destruction through enzymes and inflammation, yet they do not lead to the characteristic cytopathic effects seen with viral infections.

D. bacterial infections: Bacteria can produce toxins and cause tissue damage, but cytopathic effects specifically refer to viral-induced cellular alterations, not bacterial activity.

A. Enzymes are made of protein: Enzymes are primarily composed of protein molecules that fold into specific three-dimensional shapes, enabling them to catalyze biochemical reactions efficiently.

B. Enzymes can be denatured: Enzymes can lose their functional shape, or become denatured, when exposed to extreme temperatures, pH levels, or chemical agents, which impairs their catalytic activity.

C. Enzymes can only work one time: Enzymes are not used up in reactions; they can catalyze the same type of reaction repeatedly without being consumed.

D. Enzymes can be found in biological organisms: Enzymes are naturally present in all living organisms, where they facilitate essential metabolic and physiological processes.