Which plasma protein is the most abundant in the human body?

Albumin is the most abundant plasma protein in the human body, constituting approximately 60% of the total plasma protein content. It plays a crucial role in maintaining osmotic pressure, which is essential for proper fluid balance between the bloodstream and surrounding tissues. Additionally, albumin serves as a carrier protein for various substances including hormones, fatty acids, and drugs, facilitating their transport in the bloodstream. This multifunctionality is vital for many physiological processes, such as nutrient transport and the regulation of blood volume.

In contrast, other plasma proteins have specific functions but are present in lesser amounts. Globulins, for instance, are a diverse group of proteins involved in immune function and transport, but they do not match the abundance of albumin. Fibrinogen is primarily involved in blood clotting and is significant in the hemostatic process, yet it accounts for a smaller percentage of plasma proteins compared to albumin. Transferrin, which is responsible for iron transport, is also less abundant and has a more specialized function. Hence, while each of these proteins has important roles in the body, albumin's predominance and versatility highlight its critical status as the most abundant plasma protein.