I'd say, ina general way, that the most imporant cells in defense against parasitic organisms are definitely white blood cels, the cells responsible for defeating antigens, pathogens and deseases.
Although these might be the most important ones in that specific task (defending against parasitic organisms), all the cells in the immune system, along with other non-cell things are important, since they all play a specific role indispensable in our immune system.
Hope it helped,
BioTeacher101
Autotrophs, by definition, are organisms that are able to internally manufacture their own food. Autotrophs, also known as producers, are organisms that obtain their energy by converting light energy into chemical energy, via photosynthesis. Photosynthesizing plants are an example of autotrophs.
Heterotrophs, by definition, are organisms that are unable to internally manufacture their own food. Heterotrophs, also known as consumers, are organisms that obtain their energy by consuming other organisms. Humans are an example of heterotrophs.
Enzymes as they are biological catalysts