The two main types of proteins are fibrous proteins and globular proteins. Fibrous proteins are elongated, structural proteins that provide support and strength to tissues. Examples of fibrous proteins include collagen, found in connective tissues, and keratin, which forms hair, nails, and skin. In contrast, globular proteins are more compact and rounded, functioning primarily as enzymes, hormones, or antibodies. Hemoglobin, which carries oxygen in the blood, is a well-known globular protein. The distinct structures of these proteins influence their roles in biological processes, with fibrous proteins mainly providing structural support and globular proteins participating in various metabolic functions.