#biology studyblr

[lewiathans]

Vintage Bee Illustrations

[spendingalmytimestudying]

Another relaxing afternoon at the library

Just finished Pride and Prejudice!

[consult-sherlockholmes]

Can you explain to me the chemistry behind the denaturation of enzymes and the process of allosteric and competitive inhibition?

First of all it's important to understand what an enzyme is. An enzyme is a protein, that catalyses reactions after binding to a substrate and then converts it or splits it. An enzyme has a very specific shape so it can bind to the substrate, it's like a key and a lock. The substrate binds to the binding site, and in the catalytic or active centre the reaction takes place.

This is important to understand denaturation: Proteins are made out of amino acids that are bound with peptide bonds. Proteins have several levels of structure: Their primary level is the sequence of amino acids, the secondary structures are folded structures due to interactions of the peptide backbones via hydrogen bonds, like alpha helices or beta sheets. The tertiary structure is folding of the peptides due to electrochemical interactions between different amino acids. Amino acids can have different charges due to their side chains, they can be positive, negative or neutral charged. So those charges will either attract or repel each other, putting the peptide chain in a certain three dimensional shape or conformation. In the quaternary structure several peptide chains come together to create a bigger functional unit (the enzyme) made out of subunits, they often also interact with ions (cofactors) as their catalytic centre where the catalysed reaction takes place. All those levels create the specific shape of the enzyme that is required to bind to their target substrate. So if those structures are changed in any way, it won't work anymore because it can't bind. Just reading it probably makes it difficult to understand, so here's a textbook graphic.

This shape can be changed by denaturation. A protein can be denaturated by heat, or changed pH or high salinity and other not optimal conditions. During those conditions like changed pH the interactions between the molecules and side chains do not work anymore because pH can change the charges of the sidechains, so secondary, tertiary and quarternary structures will be changed. When those structures are changed the binding site will change too and not resemble the lock anymore where the key substrate can bind, so now the enzyme is inactivated/inhibited.

Enzymes can also be inhibited (or activated) by regulatory molecules binding to the enzyme, inhibitors or activators. This can be a competitive inhibition, when the inhibitor binds at the same binding and active site and blocking it, making the actual substrate that should be processed unable to bind there. Like a lock that already has a key stuck in it, you can't put another key in there. Allosteric inhibition is when the inhibitor binds at another site, not directly at the active site where the substrate binds. But by binding to the allosteric site the conformation of the enzyme gets changed by chemical interactions, changing the binding site so the substrate doesn't get recognised anymore. A key can't be insterted into a lock that has been changed.

Inhibtion can be irreversible (making the enzyme dysfuntional for the rest of it's existence until it is degraded) or reversible.

[bog-goblin]

Conservation Biology Student

[beesacademia]

another day of library hopping

[simpsforscience]

Anglerfish: "Til death do us part" is a bit too casual for us. We prefer "til we literally become one."

Read through to discover the bizarre world of deep-sea mating! 💑🐟

[megumi-fm]

29th & 30th Oct || 99 - 100 days of 150dop

I have reached day 100! My initial DOP goal has been met!! Yay! Now I have 50 days of productivity (and 30working days of university) left! It's so daunting that I'm close to the finish line I'm so nervous and excited and everything in between !!!!!

My next (final) semester of uni is allocated for internships- and when I asked my final project guide for advice, she told me about this one lab focusing on Computational Systems Biology. I've spent the past couple days researching about them now- their projects, members, published papers, etc etc. Lucky for me, they do some of the coolest work and it's exactly what I'm interested in! And yesterday I finally managed to gather the courage (emails are so intimidating 😣😣) and bits and pieces of my scant academic vernacular and ended up emailing the PI about potential internship opportunities. The task took so much of my mental energy that I spent the rest of the evening tired and unproductive.

However, it was all worth it when I opened my email on the way back from Uni today and noticed that the PI emailed back!! He agreed to have a call to discuss my interests and whether I'd be a good fit for his lab. The interview is on Thursday!! I'm excited nervous freaking out!! I've started looking deeper into his work and brushing up my basics as well so I can leave a good impression, let's see how it goes.

Other than that, my friends and I hung out at a cafe today after class, it was a fun time <3 I also got spotify premium with my friends xD

hope you guys are having a good day!

[just-a-girl-who-likes-sharks]

Fun fact: if you look at a closed collateral vascular bundle it looks like a happy little fella and I think that’s great

In this picture: close up of a closed collateral vascular bundle in the stem of Zea mays (cornplant).

Picture taken by myself during a lab last semester, image enlarged by a lightmicroscope (10X10X)