Proteins: Amino Acids, Polypeptides, and the Four Levels of Protein Structure

In this video, Mr. W explains the key aspects of protein structure and function. The video covers
1. The general structure of amino acids.
2. How amino acids can differ based on their side chains.
3. How amino acids link by peptide bonds to form polypeptides
4. The four levels of protein structure.
Throughout, the focus is on how protein structure can be both specific and dynamic.

The video links to an interactive tutorial at

The quizzes discussed in the video are:

Other tutorials discussed in this video:
Carbon and Functional Groups:

The material in this video covers AP Biology Topics 1.3 and 1.4.

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[sciencemusicvideos]

Guaranteed 4 or 5 in AP Bio! Free trial at

[erinrussell]

I am studying for an Anatomy and Physiology midterm and I have just stumbled upon your videos. I think I've discovered something amazing! I'll be back again and again, I think. Thanks for putting these together. Your descriptions are clear. I like the mini-breaks, asking us to put things together or try something before moving on. Slightly longer pauses between thoughts or a slightly slower speed would be nice but nothing the pause and rewind options can't handle. Thank you!

[n.g.]

I have a biochemistry quiz tomorrow. This was so helpful!
Thank you so much.

[stephaniekanu]

Funny how his body language seems like he's telling us some big urgent secret 😂😂.

Really enjoyed the video though. Subscribing!

[mishca]

I am an older adult returning to college - you've made these structures interesting and clear. THANK YOU.

[srimalkariyawasam]

Sir i'm following a educational honers degree in biological sciences.all of your vedios were very helpful to exam.continue it sir wish you all the best.

[stacieforman]

I'm so glad these are available for my students who are learning virtually. I don't have the skills or technology to make great videos like these. Thank you!

[naukadladzieci]

this should have gazillion views, trust me I checked 5 leading videos on that topic, you are the closest for my brain to get what this whole protein hierarchy is about and why, no one actually clearly says if it's just a level of complexity of different protein or whether it's the same protein approached chemically, biologically and functionally or maybe it's an 'evolving' protein shape changing protein.

[shahanabano]

Keep it up sir you are doing great work...lots of LOVE from INDIA 🙂👍

[troutwarrior]

These videos and the website are single handedly letting me pass AP bio :)

[ryansn]

What do you call an acid with an attitude?


An a-mean-o acid. HAHA

[anastasiayurchenko]

Awesome video! 👍 I’m preparing for an interview and need to refresh a bit my knowledge. Exactly what I need. Many thanks 😊

[allisonsinger]

i need to learn this from the ground up. i'm using my wife's account, as my cell died. happy to trade what i learned in stem cell research trials. i began as a cannabis grower, fighting pain and pain managed addiction in my home. i've come lightyears and designed an accelerated learning algo to aid in accelerating my learning curve/disability, while using your scholarly papers to confirm original theories far beyond the capabilities of my gear.
i reached a point in microbiology, psychiatry and my applied research in cannabis, agricultural research, behavioral research, biotech research, etc., that i need help creating a syllabus my wife can use as a spec ed doctorate, to teach me anatomy, Latin and all the other nonsense so i can continue. i'm having to use my mind to triangulate what my phytochemistry is doing and with the help of a local chemist and their gas chromatograph, it's slow going. we collaborate with a volunteer team. i'd love to fill in gaps i hear in neuro ted talks, that teach me at the same time. i'm looking to quality of life for my wife and our people. i'm using first person, as an individual with dissociative identity... it's hard enough, but i'm thinking of my wife and our peers, as i write this. it's difficult to think we're not at the top of our game, when the cannabis industry i once voted for, sounds like drug dealers to us, all over the globe. we're in the wrong "room". neuroscience seems behind, but we have plenty to learn from them. psychiatry seems behind; same dealeo. i get to microbiology and you fine folks and it sounds like we're talking about the exact same things (dropped out yr 2 of high school), but i don't share your vocabulary, having come from life experience and self-education vs more conventional ways. note buffalo ny's nod to cannabis regulation; as to criminal history. it's mes they're talking about. i'm well aware of cannabis' lethal potential because i checked so i wouldn't hurt any of the veterans i was volunteering to treat for thier pains, at the time. Our retired heroes trained me up, in layman's terms...
einstein, tesla, westinghouse, franklin began in their kitchens and garages, too. due to our health conditions, i don't have time for college applications. i'm just hoping someone can help with articles and ways for me to absorb this vocabulary, when i do best touching things and breaking them to see how they work and how to reassemble them more efficiently...
thanks so much,
on fb

[butterflyflying]

You are brilliant! I've learned in 10 min what I haven't understood in months -.-.
Thank you, and keep up that energetic spirit :)

[kimeratanko]

I loved this and will definitely be coming back. You made it very comprehensible without being overwhelmed with so much information.

[jlittlelearnersworld]

you are such a good teacher with smiles on your face

[naandremmg]

Sir, is amazing who you explained this topic, sadly my professor didn’t explain all this to us as you, but I really did understand everything you said, thank you so much! And keep going

[Leila-cuue]

Thank you! You made it so easy to understand 😊

[kingswag]

This was very helpful. Thank from Australia

[rogelindabarraza]

Thank you so much professor. I already prepared an activity for my students in which they will whatch your video!