Keratin Protein & the Epidermis

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: The Three Processes of Urine Formation

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:01 What Is the Epidermis?
  • 0:53 What Is Keratin?
  • 1:17 Keratin in Skin
  • 2:57 Keratin Diseases
  • 3:23 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Amanda Robb
This lesson is about keratin and its role in the epidermis, or the skin. We will talk about what the skin is made of, what keratin protein looks like, how it works inside the skin, and what happens when keratin creates disease in the skin.

What is the Epidermis?

Ever wonder what's underneath your skin? What would happen if your skin couldn't hold itself together? That's what we're going to cover here (pun intended)! You'll learn all about the protein, keratin, and how it holds our skin together. Our skin is actually made of three layers; the epidermis, dermis, and hypodermis. They form a skin sandwich with the epidermis and hypodermis being the bread, and the dermis being the middle.

The epidermis is the layer we're interested in for this lesson. The epidermis is the outer layer of cells in the skin. It is made of flat, scale-like, cells called epithelial cells and specialized cells known as keratinocytes. These cells protect our body and prevent pathogens from penetrating the skin. An important protein called keratin, anchors the cells together and to the layer beneath it, the dermis.

What is Keratin?

Keratin is a protein inside cells. It exists in many types of cells but it is very important for epithelial cells, which make up the skin. Keratin is a type of filament protein, called an intermediate filament. These proteins form long strands inside the cell, hence the name filament. The filaments anchor the cells to each other, which prevents the cells from pulling apart.

Keratin in Skin

Keratin has two main functions in the skin:

1. To hold skin cells together to form a barrier

2. To form the outermost layer of our skin, that protects us from the environment.

To form a barrier, epithelial cells anchor together through proteins called desmosomes. Two epithelial cells line up next to each other and attach using desmosomes. The desmosomes are like glue holding the two cells together. Inside the cell are the keratin fibers, holding the desmosomes to the cell. Without the keratin fibers, the desmosomes would just pull the membrane of the cell away from the center. The keratin anchors the desmosomes to the cell and the desmosomes anchor the cells to each other. See the desmosome junction? The cells attach to each other, and the long filaments within the junction are keratin proteins.

Desmosome junctions in epithelial cells

The second function of keratin is to form the outer layer of the skin. This happens through keratinocytes in a process called cornification. The keratinocytes in the middle of the epithelium start to make more and more keratin. As they do, they move upwards in the epithelium towards the top. The keratinocytes slowly die, leaving a thick shell of filaments inside the keratin protein. These keratin shells form the outer layer of our skin. This skin is dead and constantly flakes off throughout the day. Because the outer layer of skin is dead, it protects us against assaults from the environment like heat, pressure, or physical damage. The dead layer of keratinocytes is shown at the top. Note how the cells are not pink and enlarged, unlike the living keratinocytes below in the epidermis.

To unlock this lesson you must be a Study.com Member.
Create your account

Register for a free trial

Are you a student or a teacher?
I am a teacher

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it free for 5 days!
Create An Account