What is a Protein? Learn about the 3D shape and function of macromolecules


Proteins play countless roles throughout the
biological world, from catalyzing chemical reactions to building the structures of all
living things. Despite this wide range of functions, all
proteins are made out of the same twenty building blocks, called amino acids.
The way these twenty amino acids are arranged dictates the folding of the protein into its
unique final shape and its function. Amino acids are made of carbon, oxygen, nitrogen,
hydrogen, and sulfur atoms. 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 such as leucine and isoleucine have carbon rich side chains, which
don’t interact well with water. Hydrophilic amino acids such as serine, or threonine interact
well with water. Charged amino acids like glutamic acid or arginine interact with oppositely
charged amino acids or with water. The primary structure of the protein is the
linear sequence of amino acids as encoded by DNA.
The amino acids are joined by peptide bonds, which link an amino group and a carboxyl group.
A water molecule is released each time a bond is formed.
Specific amino acid sequences give proteins their distinct shapes and chemical characteristics.
These protein chains often folds into two types of secondary structures stabilized by
hydrogen bonds. A protein chain can fold into a rigid alpha
helix, forming regular patterns of hydrogen bonds between the backbone atoms of nearby
amino acids. Backbone atoms of the chain can interact side-by-side
to form beta sheets. Many proteins fold into a compact globular
shape, with hydrophobic side chains sheltered inside away from the surrounding water.
The functions of many proteins rely on this folded structure. For instance, 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. Many proteins rely on the ability to recognize
the shape of specific molecules in order to function correctly.
The flexible arms of antibodies protect the body from disease by recognizing and binding
to foreign molecules and thus preventing the viral RNA or DNA to enter the cell.
Collagen forms a strong triple helix that is used throughout the body for structural
support. The calcium pump moves ions across cell membranes
allowing the synchronized contraction of muscle cells.
The hormone insulin is a small, stable protein that can easily maintain its shape while traveling
through the blood to regulate blood sugar levels.
Alpha amylase is an enzyme with a catalytic site that begins the breakdown of carbohydrates
in our saliva. Ferritin forms a hollow shell that stores
iron from our food. Learn more about the functions and 3D structures
of nucleic acids, proteins, and molecular machines at the RCSB Protein Data Bank.

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98 thoughts on “What is a Protein? Learn about the 3D shape and function of macromolecules

  1. I love proteins !!! Such a marvelous machines I have ever seen !!!  The blueprint of their construction (DNA) is just mind boggling !!!
    As a mathematical physicist, I become more interested in biology, specially the recent shocking findings that plants use complex quantum physics technique to boost the efficiency of photosynthesis.

  2. This was helpful but the narration was a little too fast. I'm trying to process and understand and need to hear it a little slower 🙂

  3. how to detect in body? how and where medic found the evidence proof truth from invention , development to doctors verify coverages for certify truth 100 right for astudents goes on edu and take operation for patients ( any details labs reports proof effective  ? )

  4. http://www.mediico.com/2014/08/how-much-protein-is-healthy-for-you_31.html
    When you think about protein, athletes and bodybuilders may come to mind, but there’s much more to it than increasing muscle mass. Protein plays an essential role in keeping your body healthy. So, how much protein do you need? And is there such a thing as too much?

  5. She does talk VERY fast for all that info!  Fortunately, you can slow the audio speed if you wish.  Use settings to go as slow as 1/4 speed (.25).

  6. Cripe, the background music is distracting, and the volume of it overrides the overly-fast narration. Good animation, but please remake this.

  7. The commentator needs to speak more clearly and slowly.  Too much information for 3-4 minutes, would have been better to split it into several videos.

  8. Beautiful animation. Wide ranging and concise presentation. Thanks for the creation.
    I have protein videos as well and frequent RSCB.
    Please check out my videos; I'm DIY studio in a garage, but putting my all into and learning a lot. I'll put link in next comment.
    Thanks!

  9. I found the music so distracting, please re-edit this and re-upload. A lot of other people seem to have the same complaint, and I cannot understand as to why you haven't done it already.

  10. It would be better if you talked slower so it can be absorbed that is unless you are trying to impress people. The point is to learn here.

  11. For this sort of didactic work, which is rather complex and difficult, the author would do best in chosing a reader who can speak slowly and pronounce his words clearly. This is nearly brain wrecking to understnd at first visionning, and when you get to the end the first time, you have by necessity had to go over the video at least five times, just to understand ONCE. This speed talking is just what is absolutely unbearable on videos – plus the music indeed is too loud and does not add anything to the quality of the didactic content : on the opposite, it takes away audibility and comprehension. Authors, please, heed, when you are making these otherwise interesting videos. Thank you.
    Thanks for the effort and good continuation in video making,
    MMEJones

  12. wow!

    so enlightened by this video, I was kind of finding it hard to understand about the structures before watching it 😀

  13. one thing i cant understand is that there are only 20 amino acids and our body has millions of proteins …then how can only 20 amino acids make sucha large number of proteins

  14. so proteins are structures made from amino acids that facilitate the function of each organ and the body as a whole. is that right?

  15. [email protected] Alexander Kushelev Online service PROTEIN PICOTECHNOLOGY http://nanoworld.org.ru/topic/1699/
    The Picotech program can not completely replace X-ray structural analysis. However, it greatly strengthens the weakest points of the X-ray diffraction, namely, it shows reliably the secondary structure and the short-range order of the arrangement of the atoms of the tertiary structure at the time of assembly of the protein molecule by the ribosome.
    The sensitivity of X-ray structural analysis is such that it does not notice not only individual atoms, but also individual amino acid residues. Moreover, the "tails" of protein molecules that do not crystallize, the PCA generally "does not see", and these "tails" can consist of up to 50 amino acid residues.
    A special class is formed by 97% of protein molecules that do not crystallize. About them, the PCA simply does not know anything, and the Picotech program also reliably shows their secondary structure and short-range order of the arrangement of atoms in the tertiary structure.
    Your application must contain only the code of the protein of interest to you from the PDB database, or mRNA for it
    We will model your protein complex with ligands of any nature
    The lead time for the order is 1-7 days, depending on the complexity of the project.
    Digest https://picosoft.nethouse.ru/

  16. The information is really helpful but she talks sooo fast I have to pause every 3 seconds to write stuff down and the distracting background music makes it worse!!

  17. I want to use this video for my open educational resource course on Protein structures & functions under CC-BY-NC licence. Please allow us to use it. Thanks.

  18. Thank you so much! Very straight to the point, and it was fast at first but then when you modify the speed to 0.75 everything is perfect!

  19. To enjoy this video, you must have some other music playing in the background. I suggest this here: https://youtu.be/1GGxzSPP0J0?t=210

  20. RCSCProteinDataBank: Would you be willing to re-do this video and explain in layman's terms (with out that music)?

  21. No more distracting music. A new version of this video is available at https://www.youtube.com/watch?v=wvTv8TqWC48

  22. the music makes it more interesting. plus if the musics too distracting, that's a sign you're not really paying attention to the content

  23. as if she is trying to say something so that no one understands what she said. I wish you were a little slow and speak clearly. anyway thank you

  24. Stereometrically accurate spatial protein structures up to a picometer https://picotechnology-of-proteines.nethouse.ru/ Google Translate

  25. Is anyone here from the "Biology 1" digital textbook of The Swedish National Encyclopedia?
    Är någon här från Nationalencyklopedins digitala lärobok "Biologi 1"?

  26. The voice speaks too quickly and quietly for this to be at all educational. I'm getting maybe 10% of the words?

  27. Are you giving full credit to sulphur, which is only a contributor to protein structure but not a full contributor…..an enhancer, like oxygen to flame tho spontaneous combustion doesnt require oxygen, rather relying on enzymatic action, cellular decomposition producing heat…? By simply omitting the validity.of sulphur and including it as an equal youve change the.concept.of the protein structure and i thought it was 24 not 20….just asking….

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