what is up it's meticosis perfectionist where medicine makes perfect sense let's resume our biochemistry playlist this is good for your MCAT d80 ornate exam in previous videos we talked about amino acids the peptide bond protein protein structure I.E primary secondary tertiary and quaternary structure we talked about conjugated proteins and denaturation of proteins today we'll talk about enzymes because as you know most of the enzymes in your body are proteins enzymes are catalysts they speed up the reaction without getting changed by the reaction this is my biochemistry playlist please watch these videos in order for maximum retention what are proteins they are basically a bunch of polypeptides which are made of amino acids what kind of peptides do we have dye try oligo and poly depending on the number of amino acids so if we want to be honest and Technical you go like this one amino acid then two dipeptide tripeptide oligopeptide and then the big protein most of your enzymes are proteins protein structure could be primary secondary tertiary or quaternary primary is the sequence of amino acids secondary is the recurring patterns such as two types that we have Alpha Helix and beta pleated sheets then the three-dimensional is known as the tertiary structure and then two plus two is four two plus two is four this is the quaternary structure and this is a comparison table among the protein structures as we discussed before please pause and review conjugated proteins is a protein plus something else AKA a prosthetic group please pause and review back to amino acids which make up proteins what if I want to lump two amino acids together well you'll get a dipeptide what kind of bond should I form between them the answer is a peptide Bond how do I make this take an H from here and take an o h from here congratulations you have water okay then the rest is the peptide bond and this is an example of a chemical reaction no kidding begin with the end in mind what the flip do you want I want to make a peptide I don't want that peptide to perform an actual function then you want the peptide to be stable right yeah okay now what do you want I want to digest that peptide you want to break it down yes that's true how do you want to break it down uh in presence of water I.E by hydrolysis yeah that's right what would you call the enzyme that breaks down stuff in presence of water hydrolase because Hydro means water therefore in that sense trypsin and chymotrypsin the famous pancreatic enzymes are hydrolases why do you end in Ace because it's an enzyme most enzymes not all and an Ace and why they say hi hydrolytes because they break down stuff in presence of water okay medicosis now I want to break down the peptide bond in presence of Water by hydrolysis you mean yeah that's right using a hydrolase like trypsin and chymotrepsin yeah that's true then add water okay let me add water here O H and H and then boom you're back to amino acid and another amino acid just like that easy peasy lemon squeezy medicosis schmeezy all of this was reviewing previous videos now to today's topic enzymes the best way to understand enzymes is to imagine that you want to travel from California to New York you can do this on feet on a bicycle in a car or an airplane the airplane is the quintessential enzyme what is that because it speeds up the reaction you'll go there faster now suppose that we did not have an enzyme I.E airplane and you're going to New York in a car but not just you the 200 passengers that were supposed to be in an airplane are now driving individually each in his own car oh this will take too much time and too much energy excellent therefore by providing an airplane you're lowering the activation energy you're still arriving at the same flipping destination however you're using lower energy just like changes in weather can make or break your flight changes in PH and temperature can make or break an enzyme or a chemical reaction each enzyme has a preference it has an optimal Point optimal temperature and optimal pH you mess up with that the enzyme will not be happy with you if you want your reaction to be hydrolysis then you should talk to a hydrolase enzyme but how about talking to something else like a kinase like a oxidase reductase transformation no no no we are specific here specific for a particular reaction or a class of reactions enzymes are specific enzymes do not get changed in the reaction they are neither changed nor consumed in the reaction just like the airplane after the airplane delivers you to New York we do not throw the airplane in the trash we can reuse it again because it was not consumed did your airplane change your destination no you still arrived in New York so the equilibrium position or the equilibrium constant is the same moreover enzymes do not change the thermodynamics Thermo means hate so the heat of the reaction will not change when you travel to New York in an airplane this will not make New York cool in the summer and hot in the winter moreover enzymes do not change the overall free energy of the reaction as we will discuss soon another helpful analogy here is the initial State and here's the final State and you're trying to leave point a and go to point B you can do this uphill which takes lots of time and energy or you can go the easy route the shortcut the enzyme so that you will arrive to your destination faster and using less energy but make no mistake about it you are still arriving at the same point which is point B you see this analogy now I want you to imagine that it is fixed on this graph right here just put it upon this graph here's the initial State Here's the final State you can go uphill which takes lots of time and energy or you can go the shortcut way the enzyme way the Catalyst way which decreases activation energy on this graph What's the activation energy activation energy is the point between a which is here on this line and the crest the Zenith the top of the graph for the first graph the top is here so the activation energy is from here to here for the gray graph but for the catalyzed orange graph when we use the enzyme this is your new activation energy as you see enzymes decrease the activation energy they make it easier for you to reach your destination whether you go uphill without an enzyme or whether you use a catalyst you are arriving at the same destination there are no ifs ands or buts about it therefore if you measure the overall change of energy of the reaction which is Delta G which by the way is the difference between a and b the initial and the final State let's measure it for the gray graph all right here's point a so I'm here and here's point B so this is my Delta G for the gray graph let's repeat the same process for the orange graph where is your point L I started at the same point okay so this is my point here how about your final destination I ended up at the same point oh so you have the same Delta G that's why enzymes do not change the overall Delta G it is true that they lower the activation energy however the Delta G does not change if you want to be an excellent student bring a blank piece of paper and draw all of this better if you can do it from memory without looking if you enjoyed this video you will like my antibiotics course on my website meticosisperfectness.com and my general pharmacology course as well as my brand new surgery high yield scores oh by the way you can download all of the biology notes in PDF forms at medicosisperfectness.com and here is a 40 discount towards any course on my website use promo code taxidrone coming up next in this biochemistry playlist is the nomenclature of the enzyme times enzyme kinetics including the crazy Michaelis mint and graphs thanks for watching please subscribe hit the bell and click on the join button you can support me here or here go to my website to download my courses be safe stay happy study hard this is medicosa's perfection Alice where medicine makes perfect sense