Structural Proteins:
* Collagen: Found in skin, bones, tendons, and cartilage, provides strength and support.
* Keratin: Found in hair, nails, skin, and wool, provides protection and structure.
* Elastin: Found in skin, blood vessels, and lungs, provides elasticity and flexibility.
* Actin and Myosin: Found in muscles, responsible for muscle contraction.
Enzymes:
* Lactase: Breaks down lactose in milk.
* Amylase: Breaks down starch into sugars.
* Pepsin: Breaks down proteins in the stomach.
* DNA Polymerase: Replicates DNA during cell division.
Hormones:
* Insulin: Regulates blood sugar levels.
* Growth Hormone: Stimulates growth and development.
* Testosterone: Male sex hormone.
* Estrogen: Female sex hormone.
Antibodies:
* Immunoglobulin G (IgG): The most common type of antibody, helps fight infections.
* Immunoglobulin A (IgA): Found in saliva, tears, and breast milk, protects against infections.
* Immunoglobulin M (IgM): The first antibody produced during an infection.
Transport Proteins:
* Hemoglobin: Carries oxygen in red blood cells.
* Albumin: Carries fatty acids and other molecules in the blood.
* Transporters: Move specific molecules across cell membranes.
Other:
* Casein: A milk protein.
* Gluten: Found in wheat, barley, and rye.
* Lactoferrin: Found in milk, tears, and saliva, has antibacterial properties.
* Spider silk: Strong and flexible protein used by spiders for webs.
This is just a small selection of the many thousands of proteins found in living organisms. Each protein has a unique structure and function, making them essential for life.
