Understanding the Four Molecules of Life: Building Blocks Explained

[Music] hi it's Mr Anderson and this podcast I'm going to talk about the molecules of

Life the first time I learned this I was pretty amazed but basically the way the world works is that we eat food and then

the building blocks of that food we weave together make to make living things and so this right here is called

a Dave Thomas Dave Thomas is the founder of Wendy's but Dave Thomas and his body was made up of building blocks that came

from the food that he created in other words the proteins in the burger are broken down into amino acids and those

make the proteins in him or the sugars in the carbohydrates of the bun are broken down to make sugars that is used

in cellular respiration to make ATP to move the materials inside him or the fat inside the burger is used to make the

lipids inside the cell membranes of Dave Thomas he's actually a really fascinating guy when I read about him a

little bit didn't know this but he worked for Colonel Sanders in KFC so it's worth studying the Wikipedia a

little bit on Dave Thomas also a war hero so cool but basically um life is built on carbon and the reason life is

built on carbon is that carbon has four veence electrons in other words it has six protons that means it has six

electrons and two electrons in the first level but it has one electron in each of these if you were to draw a Lewis Dot

Diagram one of these in each of those uh outer veent shells and so basically it's really good at bonding and so the reason

life is made up of carbon is because it's fairly makes fairly stable large carbon-based molecules and that's what

we are uh if it weren't carbon then maybe it would be silicon which sits right below this I remember watching the

Star Trek episode way back in the day where there were these giant uh Rock animals called the horta and basically

this right here is Spock mind melding with a horta uh but based in Silicon and so if we were to find life somewhere out

there in the planet maybe silica would be an example of that and my computer is made up of silicon which is about as

close to Life as we have on our planet so the first thing you should understand is the idea of what a functional group

is so life is made up of carbon these huge carbon chains that's what DNA is pretty much made up of carbon and

hydrogen but there are things around the outside there are called functional groups and those give functionality they

give um Behavior to the chemicals and so if we go through these starting with the first one this would be a carboxy group

there's going to be a carbon right here at the middle and so we could abbreviate a carboxy

group by just writing Co but basically a carboxy group is going to donate this hydrogen ion and so it will make things

that are carboxilic acid this carboxy group and the amino group actually form amino acids uh next one would be the

carbonal group uh carbonal group has a carbon right here if it's in the middle we call it a ketone at the end it's

called an alide so felhide would be an example of that uh this would be a methyl group a methyl group is going to

be a carbon with three hydrogens around the outside of it methyl groups would be important in methylation so basically

what they can do DNA would be a great example of that is they can methylate organ uh uh these big carbon compounds

make them nonfunctional amino group would be another one the amino group is going to have an nh2 so it's got

nitrogen and we need nitrogen to survive and the reason we need nitrogen is to make amino acids and then basically an

amino acid which is the building block of proteins are made up of carboxy group and amino group uh next one would be the

phosphate phosphate you you may know this it's actually what's on the end of ATP it's what we use for energy transfer

uh also it's used to build DNA for example so transfer of energy would be a phosphate group and then finally we have

the hydroxy group hydroxy group is going to be an O uh what that does is make it polar and so it makes it readily

dissolvable and so if you learn these six in biology just what they are that you're going to see even in this

presentation that they're going to start showing up and you can predict some of the properties so Amino groups will

don't it'll grab onto hydrogen ion become bases um and so there's a lot of things you can learn from functional

groups but the first thing you want to do is simply memorize them now we get to the actual molecules of Life which are

mostly polymers now know this that the polymers are made up of monomers and so monomers are the building blocks and

polymers are these large macro molecules and there's only four in biology that you have to learn so it's pretty easy

but those polymers are built through a process called dehydration so if we look right here this is one amino acid and

this is another amino acid you could see right here again that there's an amino group on this side there's a carboxy

group on that side but basically if we look right here in the middle if we have two amino acids right next to each other

if I were to remove just this section right here it's an oxygen and two hydrogens what am I removing I'm

removing H2O and that's called water and so we call that a dehydration reaction because you're removing water just like

when you're dehydrated you're you don't have enough water so you remove that water and we form a Cove valent bond in

the middle that would be a peptide bond and so the proteins inside my hair and my nails and my skin and all of that is

made up of amino acids that are attached together each time we attach to amino acids we got a lose of water likewise if

we want to break it apart so let's say I eat a burger one of those Wendy's burgers and I want to break down the

proteins and then make amino acids out of it um that I can use inside my body what would be the reaction there that's

called hydrolysis so hydrolysis now is hydro water Lis means to break and so we're adding a water here in the middle

and we're breaking that Bond apart and so now we have two amino acids and so how do you build proteins through

dehydration reaction how do you break them down hydrolysis how do you build nucleic acids like DNA dehydration

reaction how do you break it down you're going to do that through hydrolysis and so even carbohydrates same way and so

let's get to those four major macro molecules the first one is going to be called nucleic acids nucleic acids the

two big ones you should understand are RNA and DNA DNA stores information inside the cell RNA is kind of a slave

to the DNA but it does work so these right here would be polymers large macro molecules what are the building blocks

it's going to be these nucleotides and so this would be a nucleotide that builds this would be one that builds DNA

so it's got a base of sugar and a phosphate and so we simply attach these over and over and over again and so it

would fit right in here and that would be one nucleotide so we attach them over and over and over again again we do that

through a dehydration reaction and eventually you have DNA so where do we get our DNA we eat our food and we break

it down into monomers and then we can weave that back into the stuff of life if we go to proteins proteins again are

made up of amino acids again here's that amino group right here would be the carboxy group right here in the middle

of an amino acid we have a carbon and a hydrogen and then on the side we have a r or side chain and so basically this is

going to be different in every amino acid and so just like we have 26 letters that make all the words in our alphabet

there are only 20 amino acids that humans need to survive and these are all 20 amino acids and if you look at them

don't memorize them that'd be silly but if you look at them what you'll see is here it is here's our carboxy group our

amino group and all of them have carboxy Amino carboxy Amino but if you look on the side this r or side chain is going

to be different in every amino acid so this would be one side chain that'd be another side chain that'd be another

side chain and we have a few properties so like these ones would all be positive these ones would be negative these ones

right here would be uncharged so they're excuse me charged and you can see like here's a hydroxy group here's a hydroxy

group here's an amino and amino group and so that's why they're charged and so basically what is a protein a protein is

this huge three-dimensional structure that's made up of sometimes thousands of amino acids attached together and so why

do they look the way they do well the order of them is important and DNA holds that but once you have all those amino

acids attached together it'll basically look like this where you have all the backbone but on the side you're going to

have all your r or side chains and so basically once you build a polypeptide or a protein it's then going to fold

into a characteristic shape like this why is it going to do that well first of all they're going to be all these Alpha

helices and basically those are built on hydrogen bonds then all the Polar Polar side chains will fold to the outside of

the protein all the non-polar hide in the middle you'll have positive attached to negative and sometimes we refer to

this all as the tertiary structure and then the quatron structure would' be you know having more than one poly pipid

attached together but when you look at me you're looking at proteins and that proteins are all built of these monomers

which are amino acids next one then would be the lipids lipids basically there's one thing that ties those all

together there are a carbon a carbon a carbon a carbon a carbon a carbon a carbon a carbon a carbon a carbon and

then hydrogen around the outside so we call these things hydrocarbons and and so this would be a fatty acid but this

would be like a triglyceride it makes that burger that fatness of the burger really good this would be a phospholipid

and that would be inside the membranes of all living material or cholesterol you can see that hydrocarbon chain right

here these things are used for energy um but they also build up membranes one more important thing about them is that

they come in two different types saturated and unsaturated basically if you're saturated it means you're

straight because you have hydrogen around the whole thing if you're unsaturated you have a Double B bond in

the middle and so things like fat uh like butter animal fat are going to be saturated unsaturated things would be

like an olive oil because if they're bent they can't quite get next to each other and so they form a liquid at room

temperature um we can make them saturated by bubbling hydrogen through it and transforming that fat so you may

be heard of trans fats and then the last one is going to be carbohydrates carbohydrates actually come in three

different types we have monosaccharides the quintessential example is gluc we have disaccharides an example of that

would be sucrose and then we have these huge polysaccharides which are hundreds and hundreds and hundreds of glucose

molecules attached together or saccharide sugar molecules attached together um so basically when you're

eating a potato or when you're eating bread or when you're eating anything that has starch it is a bunch of sugar

molecules so there's one another another another and so they're all attached together using calent bonds and so if I

want to break down carbohydrates what do I I do well I have to snip that off hydrolysis break those into sugars and

then I can use them in cellular respiration and so those are the molecules of life again there's only

four of them but if you think back to that burger and how that burger eventually becomes you it's pretty cool

process and I hope that's helpful