Metabolism | The Metabolic Map: Lipids

okay ninja in this part we're going to

continue on with the metabolic map and

we're going to specifically spoke focus

now on triglycerides and fats and how

the metabolism of fats is occurring and

how it's intertwined with this pathway

so you know within our body we store

fats in the form of triglycerides so now

let's talk about usually don't refer to

as fats we refer to them primarily as

lipids that's the more common scientific

term that we should utilize here is

lipids now lipids when we take lipids

into the body right and we store them

inside of our adipose tissue or maybe in

a little bit in the liver tissue you

store it in the form of what's called

triglycerides now triglyceride let's

write this down in triglycerides I'm

going to actually abbreviate it and

sometimes they also refer to

triglycerides as try a seal glycerol

so I'm going to write that down but then

I'm going to just talk about so the

actual name that I'm going to prefer to

is try a seal glycerol but I want you to

understand that this is the same thing

as me talking about tri glycerides it's

it's a synonym okay so me saying

triglycerol versus triglycerides doesn't

matter but I'm going to use this term to

make everything more you know small so

we can fit everything ta G that's we're

going to talk about okay so let's say

here in the body I have this thing

called a T a G a tri a seal glycerol

triglyceride let me draw the structure

of this very quickly just you know a

very raw diagram let's say here this is

the head and then there's another

component here so a try a so glycerol is

made up of two components but what I'm

going to do is let's say that I'm in the

fasting state I haven't eaten for a

while and I need some energy and my

carbohydrate source is already used up a

lot of my glycogen I already broke down

a lot of my glucose alright so I've

already done glycogenolysis I've already

done a lot of glycolysis a lot of

transition Krebs electron transport

chain now I need to set the move on to

my second source of energy my lipids

what's going to happen okay I'm going to

break the

triglyceride but I'm going to break it

down as to its two constituents so what

I'm going to do is I'm going to break

this ester bond here between these you

see these little like little tails here

these little tails are the fatty acid

and that head is the glycerol so what

I'm going to do is I'm going to break it

into its individual components one is

I'm going to break it into a component

called glycerol to stay consistent we'll

show it is like this little head like

that alright the other component I'm

going to break it into is these fatty

acid tails so these fatty acids which

would like those little tails alright so

we'll have that little thing there just

so you know keep it consistent with a

diagram now if I'm breaking down a

triglyceride or a triacylglycerol into

glycerol and fatty acids what is that oh

triacylglycerol - a glycerol and fatty

acids oh that's lipolysis perfect and

amazing so look at this me going this

way and me going this way

this is lipolysis that simple right

breaking the ester bond and breaking

these two components now here's the cool

thing about this glycerol and fatty

acids this pathway of going from tries

to glycerol to glycerol and

triacylglycerols the fatty acid is

reversible so let's say that I'm in

what's called the Fed state right so I'm

eating you're going to eat you know

there's a hormone in your body called

insolence being produced and one of the

primary metabolic effects of insulin is

once you get a lot of glucose into our

cell but it can stimulate specific

enzymes that are responsible for is

called lipogenesis so what it can do is

it can take these fatty acids in this

glycerol and use them together you know

what that's called

let's look Oh fatty acids glycerol to

try so let's roll

that's lipogenesis so the opposite

pathway me going in this direction that

is actually going to be lipogenesis and

me going in this direction this is

lipogenesis so it's so beautiful

now here's the next thing the glycerol

does it just what happens well we have

to integrate it into this pathway how do

we integrate it okay so what I'm going

to do is I'm going to take this glycerol

and I'm going to convert it into this

market you know glycerol is actually a

three carbon structure

it's actually a 3-carbon structure where

well so we see a 3-carbon structure

right here dihydroxyacetone phosphate

that's not by chance that I put it there

look what happens this guy he gets

converted into dihydroxyacetone

phosphate when he gets converted into

dihydroxyacetone phosphate what can

happen okay well two things can happen

one I didn't really mention it yet so

we're going to focus on going downwards

but we can go up I'll mention that in a

little bit but you know one thing that

can really happen it's really cool

glycerol can actually get converted to

DHAP and then where can it go let's

follow the arrows down it can get

converted to glycerol 3-phosphate or

over here to go throughout I three

phosphate the glycerol 3-phosphate can

get converted to pyruvate pyruvate to

acetyl co a goes through the krebs cycle

goes and makes nadh and fadh2 s and

makes ATP oh man it's cool all right

that's one thing so this can lead to

glycolysis what about fatty acids fatty

acids are very long-chain more common in

the body they're usually in the form of

16 carbon fatty acid room called

Palmateer co-heir palmitoleic acid what

can happen is these fatty acids that get

broken down into two carbon sequences

where do I see two carbons for us he'll

go away and look we can break this down

by chopping this actual 16 carbon fatty

acid into two carbon fragments you know

what they call this step here when

you're breaking it down you're oxidizing

the fatty acid this is called a special

step called beta oxidation okay

beta oxidation okay that's a beautiful

thing there now here's another thing

let's say that you're eating too much

you know you're cranking down her she's

crunches or you know Reese's pcs I like

Reese's Pieces are pretty good but

anyway you take it in so much glucose a

lot of glucose our body can only utilize

so much of that glucose to make ATP and

after we take in so much glucose our

body starts shunting it into making it

into fat so this pathway a pathway of

glycerol going into DHAP DHAP can

actually convert into glycerol and if

DHAP is converted to glycerol and

glycerol can actually be converted to

triglycerides what is that

that's lipogenesis so really this

structure here right this structure here

I should have blue if I'm taking this

DHAP if it's going over here and trying

to make glycerol this is a prelude to

making glycerol and glycerol is the

precursor to make triglycerides same

thing let's say I take acetylcholine

molecules and I go to the fatty acid

synthesis process so if I want to be

able to synthesize the fatty acids these

fatty acids can be utilized right to

combine with glycerol and make

triglycerides so we really wanted to we

could say this is fatty acid synthesis

that's what you really could say this is

fatty acid synthesis but it's a it's

necessary in order for the triglyceride

synthesis to occur and this one is

actually glycerol synthesis if you

really want to say that right and again

glycerol synthesis is a precursor in

order for the making the triglycerides

okay so if we really wanted to be

specific we could say this is fatty acid

synthesis and this is a glycerol

synthesis but it is necessary for making

triglycerides so technically this whole

way is lipogenesis and this whole way is

lipogenesis okay that covers that but

you know what's really crazy and

individuals who are like uncontrolled

diabetics or they've been starving

themselves or they're like on the Atkins

diet they're not taking in enough

carbohydrates what happens is their body

starts actually running out of

carbohydrates to utilize for energy that

they start breaking down excessive

amounts of fat and whenever these

peoples go up blood glucose levels go

down really really low there's a special

precursor in the Krebs cycle we're not

going to spend a lot of time I'm just

going to mention his name his name is

called whoa hey hey the same thing he

would be right here Oh a a in situations

in which we have a low blood glucose

levels Oh a a is not involved in the

Krebs cycle and it goes to make glucose

it actually goes to another pathway

we'll talk about so it goes to make

glucose eventually well if a isn't there

the acetyl co a can't go through the

Krebs cycle and so a lot of this acetyl

a starts building up when it starts

building up really really really high it

gets shunted into another pathway look

at this this is

beautiful our body is amazing okay our

brain primarily runs on glucose so they

don't really like to break down fatty

acids but our brain can use another

molecule which is really special look at

this let's say I think that's acetyl co

a and I fused them together through

special steps and I make another

molecule which is called ketone bodies

in the other ketone bodies we talked

about in great detail there's what's

called acetyl acetate and then there's

another one which is called beta hydroxy

butyrate what happens I can take this

nacido coil molecules and convert them

into ketone bodies what is that called

okay let's see if we comply to here

acetyl co a the ketone body is called

ketogenesis man so it's awesome right so

then if I'm going this way look sorry

about that and I'm going from acetyl co

a and I'm making these key to embodies

what it is call it ethical ketogenesis

now we can form these ketone bodies why

are we making these ketone bodies

because they're good for the brain so

when they go up to the brain or in the

muscle tissue so in our skeletal tissue

skeletal muscle tissue or a brain or a

cardiac muscle tissue it can utilize

these ketone bodies during the

starvation State or diabetes mellitus or

just whenever our body needs it it

doesn't prefer to use it but it can well

then these ketone bodies we have to

utilize them for energy well how do we

do that

we break them right back down to acetyl

co a hey and when we break them right

back down into a CoA that can go through

the Krebs cycle and generate energy in

the brain and in a skeletal and on the

cardiac muscle so if I want to go from

the ketone bodies to the esthetical a

then what do I need to do okay if I want

to go from the ketone bodies to

acetylcholine that's called keto lysis

I'm just breaking the ketone bodies back

into acetyl co a fragment so again this

process here of me going back up this

way is called keto lysis alright you

know it says Rios is really cool with

these a CO CO and molecules they're

really amazing I really do think these

are so cool there's one more thing that

can happen University look away is a

precursor for being able to make

cholesterol

oh so I can even make cholesterol Wow I

can make cholesterol well why would I

want to make cholesterol because

cholesterol is extremely important

you know cholesterol is important for

being able to make what's called bile

salts which is important for the

emulsification process that we're trying

to be able to help and assist in the

digestion of fat so bile salts are

really important you know cholesterol

there's a lot of hormones their

precursors to the hormones so

testosterone estrogen progesterone so

they're precursors to steroid hormones

also they're really even it's not just

that but they're also important with

inside the actual cell membrane

structure so they contribute to the cell

membrane so a lot of different things we

can convert acetyl co to cholesterol

which is a very important pathway okay

so what is that call when I go from

acetyl co to cholesterol

okay if I go from acetyl co to

cholesterol that's called cholesterol

synthesis nice so I'm just going to go

this way that's it okay and again what

is this process a good four acetyl co a

going to cholesterol is important for

the cell membrane structure it's

important for steroid hormones it's

important for bile salts and again this

process is called cholesterol synthesis

okay so what have we gone over within

this part of the video we covered how we

can break down a triglycerides into

glycerol and fatty acids which is called

lipolysis we talked about how glycerol

can be utilized within this process or

to be getting rid into DHAP right and

how that DHAP can go through the

glycolytic pathway we also talked about

how these fatty acids undergo this beta

oxidative PAP process to get converted

into acetyl co a go through the Krebs

cycle and generate large amounts of

energy we also talked about what happens

whenever too much acetyl co a builds up

right and we because we ask the Oh a egg

is converted to glucose our body needs

glucose to brain primarily runs on

glucose but whenever our skeletal

muscles on our cardiac muscles need to

contract we can convert the acetic way

into ketone bodies like a co acetate

beta hydroxy butyrate that's called

ketogenesis but then when we get them

into the brain and we get them into the

skeletal cardiac muscles we want to

break them down into a

that is called keto lysis and our body

also has the ability to make cholesterol

from acetic away which is called

cholesterol synthesis and again that's

important for making bile salts steroid

hormones and even a put component the

cell membrane and the last thing is is

whenever we're taking in too much

glucose too much of that glucose we can

shunt some of the acetic away to making

fatty acids and we can shunt some of the

DHAP to make glycerol if we do this it's

called fatty acid synthesis if we go

from DHAP to glycerol it's glycerol

synthesis but again it's all beginning

into this whole process where glycerol

and fatty acid will fuse and form

triglycerides which is called

lipogenesis iron adjourns in this video

we talked about how fats are lipids

specifically are integrated into this

whole metabolic mat pathway in the next

video we're going to talk specifically

about how proteins or amino acids are

involved in this pathway and then we'll

finish up with gluconeogenesis alright

I'll see you in a little