Question

proteins are often called the building blocks of life because they: store sugar in the body provide structure and perform many cell functions form cell walls contain phosphates

Explanation:

Proteins are large, complex molecules that play many critical roles in the body. They are made up of amino acids and are involved in almost every process within cells. One of their main functions is to provide structure to cells and tissues (such as collagen in connective tissues). Additionally, proteins perform numerous cell functions like acting as enzymes (catalyzing biochemical reactions), being transporters (moving molecules across cell membranes), and serving as antibodies (defending the body against pathogens). Storing sugar in the body is mainly done by carbohydrates (e.g., glycogen). Cell walls in plants are formed by cellulose (a carbohydrate), and while some molecules related to proteins might have phosphate groups in certain modifications, it's not the defining characteristic of why proteins are called building blocks of life.

Answer:

Provide structure and perform many cell functions