What is a Protein?
Articles Blog

What is a Protein?

August 31, 2019

Proteins play countless roles throughout the
biological world. Some transport nutrients throughout the body. Some help the chemical reactions happen at
a faster rate. Others build the structures of the living
things. Despite this wide range of functions, all
proteins are made out of the same 21 building blocks, called amino acids. Amino acids are made of carbon, oxygen, nitrogen,
and hydrogen, and some contain sulfur atoms. Selenocysteine is the only standard amino
acid that contains a selenium atom. These atoms form an amino group, a carboxyl
group, and a side chain attached to a central carbon atom. The side chain is the only part that varies
from amino acid to amino acid and determines its properties. Hydrophobic amino acids have carbon-rich side
chains, which don’t interact well with water. Hydrophilic or polar amino acids interact
well with water. Charged amino acids interact with oppositely
charged amino acids or other molecules. Primary Structure
The primary structure of a protein is the linear sequence of amino acids as encoded
by DNA. The amino acids in a protein are joined by
peptide bonds, which link the amino group of one amino acid to the carboxyl group of
another. A water molecule is released each time a bond
is formed. The linked series of carbon, nitrogen, and
oxygen atoms make up the protein backbone. These protein chains often fold into two types
of secondary structures: alpha helices, or beta sheets. An alpha helix is a right-handed coil stabilized
by hydrogen bonds between the amine and carboxyl groups of nearby amino acids. Beta-sheets are formed when hydrogen bonds
stabilize two or more adjacent strands. The tertiary structure of a protein is the
three-dimensional shape of the protein chain. This shape is determined by the characteristics
of the amino acids making up the chain. Many proteins form globular shapes with hydrophobic
side chains sheltered inside, away from the surrounding water. Membrane-bound proteins have hydrophobic residues
clustered together on the outside, so that they can interact with the lipids in the membrane. Charged amino acids allow proteins to interact
with molecules that have complementary charges. The functions of many proteins rely on their
three-dimensional shapes. For example, hemoglobin forms a pocket to
hold heme, a small molecule with an iron atom in the center that binds oxygen. Two or more polypeptide chains can come together
to form one functional molecule with several subunits. The four subunits of hemoglobin cooperate
so that the complex can pick up more oxygen in the lungs and release it in the body. Different visual representations of proteins
can give us visual clues about the protein structure and function. This space filling diagram shows all atoms
that are making up this protein. This representation, called ribbon or cartoon
diagram shows the organization of the protein backbone and highlights the alpha helices. This surface representation shows the areas
that are accessible to water molecules. Most proteins are smaller than the wavelength
of light. For example, the hemoglobin molecule is about
6.5 nanometers in size. Hemoglobin is found in high concentration
in red blood cells. A typical red blood cell contains about 280
million hemoglobin molecules. The three-dimensional shapes of proteins determine
their function. The flexible arms of antibodies protect us
from disease by recognizing and binding to pathogens and targeting them for destruction
by the immune system. The hormone insulin is a small, stable protein
that can easily maintain its shape while traveling through the blood to regulate the blood glucose
level. Alpha Amylase is an enzyme that begins digestion
of starches in our saliva. The calcium pump is aided by magnesium and powered by ATP to move calcium ions back to the sarcoplasmic reticulum after each muscle contraction. Ferritin is a spherical protein with channels
that allow the iron atoms to enter and exit depending upon organism’s needs. On the inside ferritin forms a hollow space
interior with atoms attached to the inner wall. Ferritin stores iron in the non-toxic form. Collagen forms a strong triple helix that
is used throughout the body for structural support Collagen molecules can form elongated fibrils
which aggregate to form collagen fibers. This type of collagen is found in skin and
tendons. Learn more about the functions and 3D structures
of proteins and other molecular machines at the RCSB Protein Data Bank.

Only registered users can comment.

  1. To contribute closed captions for this video in your language, use this link http://www.youtube.com/timedtext_video?v=wvTv8TqWC48&ref=share

  2. Okay. Way cool info. But the cheesy department store phone call on hold music turning up and down and coming back in and out was really distracting. As cheesy as it is either let it play or leave it out altogether.

    Good video otherwise and thanks

  3. Thank you so much. Life, all kinds, is a poem written with atoms and energy and feelings and ratio, and I don't know what else. Life is beauty. 21022019

  4. The low frequency sounds during the animated segments are very distracting, sometimes overwhelming the announcer's voice.

  5. That these little things arranged themselves in a structure so complex it could become conscious of its own existence and question it's own origin is so mind-blowing it's no wonder people believe in God.

  6. This explaination if perfect! students needs this before they start going in details in their studies! it gives them a real understanding the way the subject is here explained how reality is. not like the simplified pictures that we see everyday which does not really represent the reality.

  7. I was going to rave about cool this video is.. but I see by the comments below that everyone else has already done so. Anyhow, WOW! I wish this sort of thing was around when I was in college so many years ago. Maybe I would have learned something?

  8. This is such an informative video and I love it. The animations are incredible and extremely helpful.

  9. Carbon is hard to burn, sticks around. After softer tissue/aminos accumulated. Then bloat, water retention. Bounds to carbon.

  10. Your animation is too good but i m from other country and u should give in the below that what r u saying
    I am not understanding what r u saying

  11. …… and this all came about from an electrical charge into a pool of inanimate chemicals. Riiiiiiight. I wonder if Evolutionists ever REALLY stop and think about what they're saying?

  12. 02:31 pump..
    02:57 hemoglobin (molecule) 03:53


  13. Outstanding. Superb. Excellent. Thank you so much for making this. So dense, yet so easy to understand. Loved every second of it.

  14. so are proteins consider living things? what programed / set them up to behave so intelligently and intricately? surely trial and error / natural selection can not explain their apparent complex, intelligent-like behavior. I'm agnostic when it comes to things we cant know for sure such as the existence of some kind of intelligent creator / simulation designer but the more I learn about the details of the universe the more im convinced none of this just could've possibly just happened by accident….sure its possible we just happen to live in one of an infinite amount of varying universes that just happen to support life, but if thats the answer you need to explain all this than ask yourself why were an infinite amount of universes created in the first place.

  15. I’ve been studying nutrition/exercise science for the last decade and this beautiful video helped me conceptualize it all in a mind blowing way. I love you

  16. Thanks for relaying this information to the public. It's telling us about the magic of the world, more than we could have dreamed in our wildest dreams. That has to be good.

  17. Watch this, then follow it up with this https://youtu.be/r4sP1E1Jd_Y and for desert https://www.youtube.com/watch?v=W1_KEVaCyaA

  18. Protein is very essential for the growth of the body, to repair damaged tissue, maintaining body functions and also mainly for the immunity system to protect you. Proteins are antibodies that kill bacteria, viruses, and fungi that enter the body. They need to produce hormones that need to the function of the body. Almost all the enzymes used to digest foods are produced from them. They also help to transport various substances and compounds through the blood. As an example, Hemoglobin is a protein that transports oxygen from the lungs to other cells. Therefore it is very important to take a necessary amount of protein from foods daily.

  19. How can we know so much about all this shit and still suffer the pitifully short lifespans that we do!? Some peeps believe in voodo magic. I believe in science so hurry the f up people!!!

  20. if the ocean was filled with amino acids and goven 4.6 billion years to rub together the odds of 1 randonmly coming together in the correct order is 10 to the 104 th power agaist it happening.
    thats just one lol.
    then its just as hi that they will randomly form 1 single protein this way.
    from the big bang all the way to the creation of life there is these millions of steps that each have these type of odds against each step taking place.
    so mathmatically improbable that these odds would force any theory or idea to ve concidered false.

Leave a Reply

Your email address will not be published. Required fields are marked *