Final answer:
Keratin-containing intermediate filaments are anchored by desmosomes within cells, and they are integral to the structure and function of tissues by providing strength and resilience. Additionally, keratin synthesis begins in the keratinocytes, contributing to the tough, impermeable barrier in the integumentary system including our skin, hair, and nails.
Step-by-step explanation:
Keratin-containing intermediate filaments (IFs) are a critical component of the cytoskeleton in cells. These IFs are anchored by several shpecialized structures depending on their location. Within cells, IFs including keratin, are anchored by desmosomes to confer tensile strength to tissues. In muscle cells, IFs are anchored to Z-disks or plasma membrane plaques to facilitate the transmission of the forces of contraction. Keratin can also be found in its extracellular form as part of the air, nails, and skin where it adds strength and resilience due to its extensive cross-linking with disulfide bonds.
The synthesis of keratin begins in the keratinocytes in the stratum spinosum, where it also releases a water-repelling glycolipid. As part of the integumentary system, keratinized cells contribute to creating a tough, impermeable barrier in our skin, mouth, and nose. This versatile protein plays a significant role in the structure and function of various tissues and cells throughout the body.