What are Proteins?

Proteins Video

Proteins. You hear about them anytime you read about nutrition and exercise. Any trainer will tell you that if you want to build muscle, you need protein. Everywhere you look you see advertisements and sales for protein products. Protein shakes, protein powder, protein ice cream, protein bars—the list goes on!

What is the reason behind all of these protein products? As one of the 4 major macromolecules in our bodies they are essential to our survival and basic functions. But what does that mean? Why are they important? Why the obsession?

In this video, we will start with the basics: what are they, why are they important, and where can we get them.

What are Proteins?

Proteins are macromolecules made up of chains of amino acids that play vital roles in organisms. These macromolecules are made by the process called protein synthesis. This process occurs in 2 phases: transcription and translation.

The National Cancer Institute describes transcription as the process by which a cell makes an RNA copy of a piece of DNA. This RNA copy, called messenger RNA (mRNA), carries the genetic information needed to make proteins in a cell. It carries the information from the DNA in the nucleus of the cell to the cytoplasm, where proteins are made. Individual mRNA nucleotides come and link together over their corresponding DNA nucleotides.

DNA Base-Pairing Rules

DNA base-pairing rules are as follows:

  • Adenine binds with thymine
  • Cytosine binds with guanine

(Apples in Trees and Cars in the Garage)

RNA base pairing rules are very similar but have one major difference. In RNA there is no thymine. Instead, there is uracil. So, anytime a DNA sequence has adenine, the mRNA sequence would have uracil, not thymine

  • Adenine binds with uracil
  • Cytosine binds with guanine

(Apples Under a tree and Cars in the Garage)

Then, that mRNA molecule leaves the nucleus to go to a ribosome, where the protein is actually put together. During translation, the mRNA is read and used to bring the correct amino acids together. Each amino acid corresponds to a section of three mRNA nucleotides and uses the mRNA template to make sure they link together in the correct order.

The chain is then folded into a particular shape based off of the polarity of the amino acids. And there you have it—a protein!

Protein Sources

There are about 20,000 different types of proteins in the human body, and each one is assembled from a pool of 20 different amino acids. The order, length, and folding of the amino acid chain is what determines a protein’s function. If there is an error in the order of amino acids or the folding of the chain, the protein will not function.

How do we get those amino acids to make the 20,000 proteins our body has? Well, they are in all those protein products I mentioned earlier, along with other meat, dairy, bean, fish, and egg products. These foods and drinks all have a variety of the 20 amino acids needed to build proteins. When you eat these foods, your body breaks them apart and rearranges the amino acids into the order of the protein your body needs. It’s like taking apart a block tower and using the pieces to build another structure.

It’s usually meat products that are advertised as being high in protein, but what if you don’t eat meat? There are plenty of other foods, including dairy, eggs, and beans, that contain high amounts of protein, and, therefore, amino acids, that can be digested and reassembled in the body. This means you can still have protein in your diet from whole foods without eating meat!

Protein Functions in the Body

Once we have eaten food, broken it down into amino acids, and made our proteins, they can be used all throughout the body in a wide variety of functions; they are not limited to one area or job. A few of the main functions of proteins include:

  • Forming the cell membrane in every cell
  • Aiding in the growth and development of the body
  • Sending messages throughout the body
  • Transporting oxygen
  • Catalyzing chemical reactions
  • Signaling cell growth and death

All of these jobs and more keep the body at homeostasis and functioning properly.

With the variety of functions comes the abundance of locations. When your body digests food, the nutrients go into your bloodstream and go all over the body. In this case, the amino acids travel through the bloodstream and into the cells of different systems to be made into proteins.

One of the main systems talked about in regard to proteins is the muscular system. When you exercise, your muscles tear slightly, and when that happens, proteins come in and fill the gaps to repair them. The more tears, the more proteins come and fill them. This is the main reason why athletes, body builders, and people with a goal of building muscle may take protein supplements. They are tearing their muscles up more and need more protein to fill in the gaps and help them build muscle.

They also are in need of proteins in other areas of the body too, like in the cardiovascular system. One of the main jobs of this system is to move oxygen from your lungs to the rest of your organs. How does it do this? Well, you need a special protein that allows those oxygen molecules to travel through the bloodstream – hemoglobin!

From organs to vessels, proteins are there on even the smallest level – cells themselves. Every cell has a membrane, and every one of those membranes contains proteins. These proteins allow certain molecules to enter the cells and keep the rest out.

Different Types of Proteins in the Body

Working our way from top to bottom, you can find all sorts of other proteins in the body.

  • Hormones being released from the pituitary gland in your brain
  • Amylase breaking down carbohydrates in your mouth
  • Hemoglobin transporting oxygen from your lungs
  • Antibodies being released in your lymphatic system
  • Collagen in your skin and muscles
  • Lactase breaking down lactose in your digestive system
  • Keratin in your fingernails and toes
  • And thousands more!

With all of these examples, you can see how important proteins are to our body and why it’s important that we consume enough in our diets. Our lifestyle, age, and weight all play a factor in how much protein is needed for our individual bodies.

To wrap up, proteins are crucial for our body’s health and function. They help fix muscles, carry oxygen, and much more. That’s why eating enough protein from various foods is key, whether you’re working out or just staying healthy.

That’s all for this review. Thanks for watching, and happy studying!

Frequently Asked Questions


What are proteins made of?


Proteins are made of carbon, hydrogen, oxygen, nitrogen, and sometimes phosphorus, sulphur, and/or iron.


What are the monomers of proteins?


The monomers of proteins are amino acids. Proteins are made up of chains of amino acids.


What is the function of proteins?


Proteins provide support and structure for cells. Other functions of proteins include transporting molecules, such as oxygen, throughout our body, communicating messages between cells, and working with our immune system to keep us healthy.


What are some examples of proteins?


Some examples of proteins are actin, tubulin, hemoglobin, insulin, and immunoglobulins.



by Mometrix Test Preparation | This Page Last Updated: March 29, 2024