What substance primarily helps transport nutrients throughout the body?

Blood plasma is the liquid component of blood that serves as the primary medium for transporting nutrients, hormones, waste products, and other substances throughout the body. It contains water, proteins, electrolytes, and various molecules that facilitate the movement of these essential nutrients to cells and tissues. The proteins found in plasma, such as albumin and globulins, play important roles in maintaining osmotic pressure and transporting different substances, including lipids and fat-soluble vitamins.

In contrast, platelets are involved in blood clotting and are not directly responsible for nutrient transport. Lysozymes are enzymes that help in breaking down bacterial cell walls, playing a role in the immune response but not in nutrient transport. Serum is essentially blood plasma without the clotting factors, limiting its role in transport when compared to the complete plasma, which contains important components for nutrient distribution.