Login

What Are Antibodies? - Definition, Function & Types

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: What is a Gene Pool? - Definition & Example

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

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:00 What are Antibodies?
  • 0:25 Function
  • 0:55 How Antibodies Fight Antigens
  • 1:45 Immunizations
  • 2:40 Types of Antibodies
  • 4:35 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

Timeline
Autoplay
Autoplay
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: Kelly Robson

Kelly has taught High School Science and Applied Communications. She holds an Education Specialist Degree in Ed. Leadership.

Antibodies play a key role in the immune system. They begin the process of getting rid of the invaders that may cause harm or infection. This lesson covers how antibodies work and the different kinds of antibodies.

What Are Antibodies?

Antibodies, also known as immunoglobulins, are Y-shaped proteins that are produced by the immune system to help stop intruders from harming the body. When an intruder enters the body, the immune system springs into action. These invaders, which are called antigens, can be viruses, bacteria, or other chemicals. When an antigen is found in the body, the immune system will create antibodies to mark the antigen for the body to destroy.

Function

The antibodies act sort of like the immune system's scouts. They find antigens, stick to them, and identify for the immune system the exact type of antigen so that it can be destroyed. Each antibody is made for one and only one antigen, and it's fitted with special receptors that will only bind to that antigen. For instance, a specific antibody is created to help destroy the chickenpox virus. Only that particular antibody will attack a chickenpox virus.

How Antibodies Fight Antigens

So what happens when an antigen tries to enter the body? When it does, the immune system is triggered. Chemical signals are sent to alert all the different parts of the immune system into action.

First, the virus is met by a type of cell called B cells. The B cells are responsible for creating antibodies to match the antigen. Remember, each type of antibody matches to only one antigen. After the B cells have created their antibodies, the antibodies stick to the virus, marking it for the next round of attack. T cells are then ordered to attack the antigen that the antibodies have marked for it.

After the antigen has destroyed, the cleanup crew comes along. A wave of phagocytes, large cells that can consume foreign matter, eats the remains of the infection.

Immunizations

After an infection is defeated, the antibodies still remain in the body. They are left there to wait in case that particular antigen returns. For example, after a person gets chickenpox, the antibody that was created by the immune system to get rid of the chickenpox will remain in the body. The next time the chickenpox virus tries to invade the patient, the antibody will be ready. It will instantly attach to the virus, calling the T cells and phagocytes much quicker, and stopping the infection much earlier.

Immunizations take advantage of the fact that antibodies remain in the body after an infection is eradicated. Most immunizations consist of a weak or diluted form of an antigen - not enough of the antigen to make the patient sick, but just enough to trigger the creation of antibodies. This way, the body can instantly attack any form of the infection it encounters, stopping the infections before they begin.

Types Of Antibodies

In total, there are five types of antibodies. Each type is found in a different part of the body and has a different set of duties. Each one of them is referred to by a letter following the abbreviation Ig for immunoglobulin.

The most common antibody we have is the IgG antibody. IgG is found in all of the body's fluids. It makes up about 75-80% of all of our antibodies. These antibodies help to fight off bacteria and viruses. To go with the flow of the fluids, IgG antibodies are the smallest antibodies in size.

The biggest in size are the IgM group, found in the lymphatic and circulatory systems. The IgMs are the first responders, the first type of antibodies to confront invaders to these two systems.

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
What is your educational goal?
 Back

Unlock Your Education

See for yourself why 10 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
Support