0:04 okay ladies and gentlemen good day all
0:06 my name is MTAR Ali from Department of
0:09 biochemistry AB idea
0:12 today we are going to look at the
0:14 concept of enzymes catalysis please if
0:16 you are coming for the first time to my
0:19 YouTube Channel Please
0:23 Subscribe what is enzymes enzymes are
0:26 Catalyst they increase the speed of
0:28 chemical reaction without themselves
0:32 undergoing any pH chemical change so it
0:35 means that enzymes they are molecules or
0:37 they are proteinous in nature or they
0:41 are protein molecules that speed or that
0:44 increase the chemical reactions in a
0:48 Cell generally there are thousands of
0:50 reactions that are taking place in our
0:56 body and some reactions can take years
1:01 before complete so as a result of that
1:05 if there is a slow in biochemical
1:06 reactions in a Cell so there is a
1:08 likelihood that the
1:13 energy or the demand of the cells cannot be
1:15 be
1:20 uh the man of the cells cannot
1:23 be met so as a result of
1:26 that there are enzymes which generally
1:28 speed of the reactions instead of the
1:30 reactions to take his
1:32 instead of the reactions to take month
1:35 instead of the reactions to take hours
1:37 in just milliseconds they will easily
1:41 comat that reactant to products so
1:43 generally when we are thinking about
1:46 reactions we talking about reactant and
1:50 products but in the case of enzymes we
1:52 are not usually
1:56 called reactant as a reactant rather we
1:59 call it we call them substrates so
2:01 generally enzymes they are molecules
2:04 that speit the rate of the reaction so
2:06 that the reactions cannot take years
2:09 cannot take hours because as long as the
2:12 reactions is
2:15 not taking place at a required time so
2:18 there's a likelihood that the cells will
2:20 die and of course once the cell when the
2:24 cells is die it means that the living
2:27 organisms should entirely die so that is
2:28 why these enzymes are very very
2:31 important they are very very essential
2:33 living organisms so they increase the
2:36 rate of the reactions withouts being
2:40 consumed so they not change if enzymes a
2:44 combine substrate a to product a or to
2:48 product p means that the enzymes will
2:50 return it is integrity it will return
2:53 return it is chemical nature it will not
2:56 change and it is
3:00 recycle and uh used to combat another
3:02 substrate so that is in the case of
3:05 enzymes so enzymes they are biological
3:08 molecules that speed the rate of
3:10 biochemical reactions and they did not
3:13 consume nothing is change on the enzymes
3:16 but they change the substrate
3:22 or product so enzymes neither speit off
3:26 in the reaction no they appear as
3:30 reaction product so they do not
3:34 use off they can not use
3:39 off and they do not aair as reaction product
3:40 product
3:45 so they are not used of and you cannot see
3:46 see
3:49 them in the product
3:52 produce so it means that the enzymes
3:55 that is just it will change the
3:58 substrate the product without it being
4:03 used of and without aaring on the product
4:04 product
4:09 produced so these are some of enzymes
4:11 generally enzymes are high molecular
4:14 with proteins although it's not all
4:17 enzymes that are proteins there are some
4:20 enzymes that are nucleic acid in nature but
4:21 but
4:24 99.99% of the enzymes are proteinous but
4:26 very few are nucleic acid in nature so
4:29 they have high molecular weights which
4:34 we range from 10,000
4:38 to million G per Mo so it means that
4:41 their molecular weight is
4:43 huge and the
4:46 substrates specific
4:51 catalyst so they are specific recognize
4:54 and catalyze only their substrate if
4:56 enzymes is responsible for converting
4:59 glucose to glucose six prates that the
5:01 same enzymes cannot be used to convert fructose
5:03 fructose
5:06 to fructose prosate so it's not possible
5:09 so enzymes they are specific their
5:12 substrate and they have high efficient
5:15 they are highly efficient they are
5:18 highly efficient increasing reaction
5:21 rate by a factor as high as
5:26 10 Power 8 so it means that enzymes they
5:29 increase the rate of the reaction by a
5:35 Empower it is huge so the factor is huge
5:38 so that is why enzymes reaction is very
5:43 very essential as it's reduce the time
5:45 for the reaction to take
5:49 place so it increase the reaction by a
5:57 8 and then we have enzymes num cature so
5:59 the earliest enzy that we discovered
6:01 that that was discovered have
6:04 become names like for example in the
6:08 older days pin raining
6:11 triin pancreatin that is the name of
6:16 most of the enzymes but with some
6:18 development with an
6:23 IAC achievement the enzymes named for
6:27 most other enzymes and in as so that is
6:29 why now you can that most of the enzymes
6:32 the name is ending with ASB
6:40 K amas lipas
6:43 sucas so most of the enzymes anywhere
6:47 you see the word and with as it means
6:50 that that substance is an enzymes or
6:52 that molecules is an enzymes
6:58 so they usually end with as e so the
7:00 enzymes name usually the enzyme name
7:03 indicate the substrate acted opened and
7:06 the type of reaction that it catalyze so
7:09 in most cases if you know or if you see
7:13 enzymes you can clearly see them with
7:15 the names of the substrate that they act
7:19 on like we have an enzymes called gluc
7:21 because they act on
7:23 glucose we have some enzymes called
7:27 hexin because they act on six carbon
7:30 sugar we have some enzymes called glycer
7:32 Aly three phosphate de
7:35 hydrogenous because they act on the
7:40 hydrogen it act on glycerol three
7:43 phosphates so most of the enzymes they
7:45 have the name of the substrate they act
7:49 on and the types of reaction that it
7:53 catalyzes so like for example gal three
7:55 phosphate dehydrogen it means it's an
7:58 enzyme that catalyze
8:00 dehydrogenation of
8:03 LOL the three phosphat so most of the
8:05 enzymes they have the name of the
8:07 subrate that they act on and also the
8:10 types of the reaction that they catalyze
8:12 we have some transfer enzymes like
8:16 alanine amot transfer so most of the
8:20 enzymes have the name of the substrate
8:23 and the types of the reaction that they
8:26 catalyze so enzymes name examples of
8:30 enzymes name we have glutamic
8:36 transamin see this one from the word
8:40 transamin it means it caliz trans
8:44 amination like the transfer of Amo GP
8:47 and of course it act on the substrate is
8:50 glutamic acid so we also have l
8:54 aspartate 2 oxy glutarates amot
8:57 transference so the enzymes name tend to
9:00 be long and complicated they are often
9:03 abbreviated with acronyms so in most
9:06 cases so how these
9:10 enzymes catalyze reaction so one of the
9:14 mechanisms of the enzymes catalysis is
9:17 the enzymes usually have active sites
9:20 where the substrates bind to so this is
9:23 a substrate this is our
9:26 substrates so the substrate
9:29 here will now bind to the active side of
9:31 the enzymes so this is the active side
9:34 of these enzymes to now bind to the
9:37 active s so the enzymes and the substrates
9:39 substrates
9:42 react and form what you call enzyme
9:44 substrate complex and the enzyme
9:46 substrate complex will now break down to
9:49 produce the free enzymes and the
9:51 substrates so now if you look at it from
9:54 the substrates the product there is a
9:56 change in substrate to product in terms
9:59 of col and the number of product prod so
10:02 it means that from one single substrate
10:04 two products are
10:07 generated so from one substrate two
10:10 products are generated and the color has
10:12 changed but in the case of enzymes what
10:14 you have before the reaction and after
10:17 the reaction is the same so that means
10:20 that the enzymes are not used off and
10:24 they do not change in any form so that is
10:26 is
10:30 uh enzymes catalysis so
10:32 the enzymes usually bind to the
10:35 substrates using the active sites the
10:36 enzyme substrate complex will be
10:40 generated and then finally the enzymes
10:43 will form a product so the product
10:46 usually change from substrates and then
10:49 the enzymes doesn't change in the course
10:52 of the chemical
10:56 reaction so that is um the mechanisms of
11:06 so how is these enzymes catalyze the
11:10 rate of biochemical reaction so the way enzymes
11:11 enzymes
11:14 catalyze biochemical reaction is
11:17 actually through reducing the energy VAR
11:19 which is activation energy so this is an
11:22 uncatalyzed reaction so generally for a
11:25 chemical reactions to OCC reactant
11:28 particles must produce or must collide
11:29 with one another
11:31 and the collusion must be perfectly
11:33 elastic so that the substrate will now
11:37 produce a sufficient energy overcome the
11:39 activation energy before the reaction
11:42 take place so before the reactant
11:44 produce a product the reactant must
11:47 Collide to produce sufficient energy
11:51 that will overcome the uh energy Vara
11:54 which is the activation energy so in the
11:58 case of uh enzymes catalyzed reaction
12:01 what the enzymes that it just reduce the
12:04 activation energy so that the substrate
12:07 can easily react to produce a product
12:09 and that is how the enzyme speaks the
12:11 rate of the chemical reaction is through
12:13 producing the activation energ that is
12:15 the energy VAR and of course if you can
12:17 see it clearly here you see that the
12:20 activation energy here is high while the
12:24 activation energy EA here is lower
12:27 compared to the uncatalyzed reaction so
12:29 that is why this substrate for this
12:32 substrate to easily convert to produce a
12:36 product here it's simple compared to
12:41 from here to here it means that in the
12:44 absence of enzymes there must be a
12:47 sufficient energy that will now jump or
12:51 overcome the activation energy but here
12:54 when there is an enzym the enzyme justu
12:56 the activation energy so that the sof
12:59 can easily comvert to product so that is
13:01 how enzymes increase the rate of the
13:05 reaction is by reducing or decreasing
13:08 the activation energy of the reaction of the
13:16 now we now going to look at the enzyme
13:19 specificity to the action of an enzyme
13:21 defend primarily on tiary andary
13:23 structure of the protein that
13:26 constitutes the enzymes and of course in
13:30 the case of enzymes we have of enzymes
13:33 are proteins and of course proteins
13:36 have various level of structure we have
13:37 primary structure we have secondary
13:40 structure we have tertiary structure and
13:42 quary structure so most of the enzymes
13:45 are in tertiary and quary structure and
13:47 it's actually that tertiary andary
13:50 structure that make them to carry out
13:53 their enzymes catalysis but once the
13:55 tertiary andary structure is being
13:58 destroyed it means that the enzymes
14:02 activity itself will also be destroyed
14:05 so the action of an enzymes is primarily
14:08 depend on it primarily depend on
14:14 primarily depend on the tary and Partin
14:16 structure of the protein so it means
14:19 that if the prary andary structure of
14:22 the enzymes proteins is destroyed it's
14:25 it's it's the nature it means that there
14:27 will be no activity and some of the
14:30 things that destroy the active site of
14:33 or that destroy the tary andary
14:35 structure of the proteins include high
14:38 temperature high ionic strengths and so
14:42 many other factors like pH
14:46 so and the F of the enzym structure that
14:52 acts on the substrate is the active SES
14:54 so there is a fat that is found on the
14:57 enzymes called active site where the
15:00 substrate binds for the catalysis to
15:04 take place and in this active site of
15:08 the enzymes there are Amo acids there
15:11 are amino acid which is called amino
15:13 acid residual so it means that in the
15:17 active s in the enzymes there is a c or
15:20 there is a cocket called active site
15:22 where the substrate finds for the
15:25 catalysis to take place so this active
15:27 side of the enzymes there are amino
15:29 acids that are found which involved in
15:32 the catalysis and these amino acid that
15:33 are found in the active side of an
15:37 enzymes are called amino acid resides
15:40 they are called amino acid resid and
15:43 usually in the active side of the of the
15:46 enzymes the amino acid are usually far
15:49 apart they are far apart they are
15:52 lengthy they are far apart they are not
15:57 in plus proximity so the active sites of
16:01 the enzymes is a groove or a pocket in
16:03 the enzy structure where the substrate
16:07 combined so this is specifically if you
16:11 can now see this is an enzymes e and of
16:13 course this is the active side so
16:16 everything here everything here is
16:18 called active side everything here is
16:22 called active side of the enzymes so
16:24 this is the active side where the
16:26 substrate and this the substrate where
16:29 the substrate finds so it's called this
16:32 is the enzymes entirely and this is the
16:34 pockets all active side that are found
16:37 in the enzymes and this active side of
16:40 the enzymes is divided into two we have
16:42 binding side and we have catalytic side
16:44 so the active side of the enzymes is
16:47 divided into two which is called binding
16:49 side and catalytic side so what is the
16:50 difference between binding side and
16:53 catalytic side of an enzymes The Binding
16:55 side of the enzyme it usually chooses
17:00 the substrate and binds it to the s of
17:03 course the enzymes are very specific The
17:06 Binding site of the enzymes is the site
17:11 where usually chooses chooses the the
17:14 the the perect substrates or the
17:16 specific substrates and binds to it and
17:19 that is what make enzymes to be specific
17:22 like for example if you have glucose and
17:25 fructose and the enzymes is meant to
17:29 catalyze let's say the enzymes is glinus
17:32 and is meant only to faly glucose not
17:34 substrate so it means that the binding
17:38 SES of the enzyme is the site that has
17:41 the responsibility of
17:45 choosing glucose not fructose and then
17:48 bind it bind it to the active site while
17:51 after binding it to the active site then
17:54 the catalytic site is is it's it is the
17:57 one that performs the catalytic action
18:01 of the enzymes so The Binding s is the s
18:03 that recognize the substrate and binds
18:05 to the active site and the active site
18:08 now will now will now undergo the catalytic
18:10 catalytic
18:13 activity of the substrate to products so
18:15 this is
18:18 um the case of enzyme specificity so
18:20 enzymes are specific because of the
18:23 binding side that usually Rec
18:26 organize a required or a specific
18:29 substrate bind to it and all the
18:31 catalytic site to
18:35 carry it is entic activity or the catalytic
18:41 activity so that is for the enzymes
18:43 activity and then the next thing is cor
18:47 factors cor factors what are co-actors
18:51 co-actors are other compound or ions
18:55 that enzymes require before their
18:59 catalytic activity can occur so factor C
19:01 they are compounds there are other
19:03 compounds and they are not
19:06 proteins they are not proteins but they
19:09 are compound or ions that
19:11 enzymes before their catalytic activity
19:13 can OCC it means that if there is no
19:16 co-actors there will be no catalytic
19:18 activity so the protein potion the
19:20 protein portion of an enzymes is
19:24 referred to as AL enzymes so in the
19:26 enzymes in the enzymes we have to FR
19:29 potion we have Flo portion and we have
19:32 non protein portion so the protein
19:34 portion of an enzym is called Alo
19:37 enzymes and then the enzymes plus the co
19:40 Factor when you have enzymes and you add
19:42 it with the co-actors is what you call
19:46 Hol enzym so Hol enzymes is the active
19:48 form of the enzymes so if there is no
19:50 co-actors it means you have apple enzyme
19:53 and if it is only Apple enzymes you have
19:57 it means that the enzymes in is inactive
20:00 if it is a enzymes it indicate that the
20:03 enzymes afo enzymes if you have Alo
20:05 enzymes which is the protein portion is
20:08 usually inactive and there is co-actors
20:11 and this co-actors when binds to the
20:14 enzymes then it now become the whole
20:16 enzymes which is called Holo enzymes
20:19 Holo enzymes means all enzymes and it's
20:21 the active form of the enzym so if there
20:24 is no Holo enzymes if there is no Holo
20:28 enzymes it means sorry if there is no
20:30 COA it means you only have alha enzymes
20:34 and alha enzymes cannot work cannot work
20:37 it's inactive so this co-actors is
20:40 divided into three we have essential
20:43 ions we have essential ions and we have
20:46 Co enzymes and we have prosthetic groups
20:48 so what is the difference between
20:50 coenzymes and prosthetic groups so the
20:54 co-enzymes they are they are molecules
20:58 that are Loosely bound the Apple enzymes
21:00 they are Loosely they are not that
21:03 tightly bound but we have prostetic
21:07 group which is the one that strongly
21:10 bound the aloh enzymes that is prostatic
21:13 group and then you also have essential
21:16 ions and this essential ions can be
21:19 activat metal ions which is usually
21:21 loely bound like for example in the case
21:24 of exoc is an enzyme that convert
21:27 glucose to glucose phosphates and the
21:31 enzymes need activat metal example of
21:34 the activator metal of hexin is
21:36 magnesium so it's usually it's Loosely
21:40 bonded like for example let me just give
21:50 reaction so in a situation where we have like
21:55 luuc
22:04 and enzymes called hexus
22:06 hexus hexo
22:08 hexo
22:12 Kus I need a substrate and so need a CO
22:15 factor and the core factors is magnesium
22:17 ion for it to
22:22 produce glucose six phosphates so these
22:28 kinds of activator ions is is this is a
22:31 typical example of an activator ions
22:34 that is Loosely bound but we have metal
22:38 ions of meal enzymes which is tightly
22:41 bonded like for example in the case of
22:45 hemoglobin we have ion Fe it's an examples
22:46 examples
22:50 of methal ions of methal enzymes it
22:53 means that they are the enzymes that are
22:57 or they are the proteins that they have
23:03 a metal ions that is from the part of
23:04 the proteins or enzymes that's why they
23:06 are called methal enzymes because they
23:12 are enzymes that have opao or metal ions
23:16 that fully integrate to it
23:18 so that is
23:23 for uh that is the cor factors and we
23:27 have some examples of the co-actors here like
23:29 like
23:32 we have ion F we have Mangus we have
23:36 magnesium and we have zinc so this this
23:39 ions that are here are typical examples
23:42 of the essential ions that are found in
23:51 in enzymes so ladies and gentlemen if
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