Are responsible for the structures and functions of organisms.

The right answer is proteins.

Protein functions are very varied and are used as a basis for classification.

There are several groups:

* Enzymatic proteins: any protein catalyzing biological reactions Antibodies: defense proteins

* Transport proteins (molecules, or various ions): we can mention myoglobin and hemoglobin, which are capable of binding reversibly oxygen, but also blood lipid transporters, membrane transporters ( pump type, channels ...)

* Regulatory proteins: they participate in the regulation of extremely diverse cellular or physiological processes. We can mention: protein hormones, all the receptors and proteins associated with these receptors, the proteins involved in cellular transduction phenomena, all the proteins involved in the control of gene expression ...

* Contractile proteins: involved in cell motions. We can mention: actin, myosin, tubulin

* Reserve proteins: serve as reserve amino acids, stored massively at a period of development then are used and hydrolyzed massively at another stage of development: ovalbumin of eggs, grains of aleurones in the albumen seeds (which contain gluten in wheat ...)

* Architectural proteins, which participate in the construction and maintenance of cell and tissue structures, but also participate in the protection of certain types of cells: keratin, collagen, fibroin (spider webs) ...

an adaptation is a change or process by which an organism takes to be better suited for its environment. for example; migration is a behavioral adaptation, this is needed because birds are not built to last extremely cold climates. there are different adaptations because there are different species needing to adjust to different things, bears don't migrate; they hibernate.