Lipids

Summary

In this podcast, Mr. Andersen explores lipids, detailing the structure and function of triglycerides, the primary form of dietary fat. He explains how fats provide energy and form cell membranes, highlighting the difference between saturated and unsaturated fats. Mr. Andersen also discusses the artificial fat olestra, its unintended health effects, and the role of cholesterol in maintaining cell membrane fluidity. The summary concludes with a personal note on the ubiquity of fats in modern diets and their potential health implications.

Takeaways

• 🍲 Lipids, such as fats found in butter and olive oil, are primarily triglycerides with a glycerol head and three fatty acid tails, which are a source of energy for the body.
• 🔬 Enzymes called lipases break down triglycerides, allowing the body to utilize the stored energy within fats.
• 🧬 Fats are not only energy sources but also crucial for the structure of cell membranes, which are composed of phospholipids and cholesterol.
• 🌡 Cholesterol plays a vital role in maintaining the fluidity and integrity of cell membranes, especially in varying temperatures.
• 🔗 The hydrocarbon chains in fatty acid tails, consisting of carbon and hydrogen bonds, store significant energy that can be released through cellular respiration.
• 🔍 Fatty acid tails can be saturated, meaning they are straight and typically solid at room temperature, or unsaturated, which are bent and usually liquid at room temperature.
• 🧪 Industrial processes can convert unsaturated fats into saturated fats, such as making margarine from vegetable oil, but this can have health implications.
• 🚫 Trans fats, often produced during the hydrogenation process, are considered harmful and can contribute to arteriolosclerosis.
• 🍫 Olestra is an artificially created fat substitute that the body cannot break down, leading to it passing through the digestive system without being absorbed, but it has caused adverse reactions.
• 🌀 Phospholipids, with their charged heads and uncharged tails, form the basis of cell membranes, allowing for selective permeability and maintaining cellular functions.
• 🍔 Despite the need for lipids in our diet for energy and cell membrane formation, modern diets often contain excessive amounts of unhealthy fats, such as trans fats found in some fast foods.

Q & A

What are triglycerides composed of?

Triglycerides are composed of a glycerol head and three fatty acid tails.

How do enzymes called lipases function in relation to fats?

Lipases break down fats, allowing us to extract energy from them.

What is the role of fats in the body besides providing energy?

Besides providing energy, fats are crucial for forming cell membranes.

What is the structure of a hydrocarbon?

A hydrocarbon is essentially a chain of carbon atoms bonded to hydrogen atoms.

What is the difference between saturated and unsaturated fatty acid tails?

Saturated fatty acid tails have hydrogen atoms all around, making them straight, whereas unsaturated fatty acid tails have double bonds that create bends or kinks.

Why are saturated fats solid at room temperature?

Saturated fats are solid at room temperature because their straight tails allow them to pack closely together.

How can vegetable oil be transformed into margarine?

Vegetable oil can be transformed into margarine by bubbling hydrogen through it, which straightens the tails and makes it a solid at room temperature.

What is olestra and how does it affect the body?

Olestra is a synthetic fat built around a sucrose molecule with multiple fatty acid tails. It cannot be digested by the body, so it passes through without being absorbed.

What are phospholipids and why are they important?

Phospholipids are lipids with two fatty acid tails and a phosphate group head, crucial for forming cell membranes that regulate what enters and exits cells.

How does cholesterol contribute to cell membrane integrity?

Cholesterol helps maintain cell membrane fluidity by holding fatty acid tails together when it gets too warm and keeping them apart when it gets too cold.

Why do we need lipids in our diet?

We need lipids in our diet to provide energy and to make cell membranes.

What can excessive consumption of trans fats lead to?

Excessive consumption of trans fats can lead to arteriolosclerosis and heart disease.

How do phospholipids behave in water?

Phospholipids form spheres called micelles or spontaneous membranes in water due to their charged heads and uncharged tails.

What happens to the structure of the cell membrane at different temperatures?

At high temperatures, phospholipids in the cell membrane can fall apart, while at low temperatures they can crowd together, affecting membrane fluidity.

What was a notable adverse reaction to consuming Wow chips with olestra?

Consuming Wow chips with olestra caused cramping and loose stools in many people.

Outlines

00:00

🍗 Lipids: Energy Storage and Structural Role

Mr. Andersen introduces lipids, emphasizing their dual role as an energy source and structural component in the body. Triglycerides, composed of glycerol and fatty acids, are the primary form of fat found in foods like butter and olive oil. They can be broken down by enzymes for energy. Lipids also form the cell membrane, with phospholipids providing structure and cholesterol maintaining fluidity. The energy within lipids comes from hydrocarbons, which are chains of carbon and hydrogen atoms found in the fatty acid tails. The difference between saturated and unsaturated fats is highlighted, with saturated fats being solid at room temperature and unsaturated fats being liquid due to the presence of kinked tails from double bonds.

05:05

🧪 Manipulating Lipids: Margarine, Olestra, and Phospholipids

This paragraph delves into human manipulation of lipids, such as converting liquid vegetable oils into solid margarine by hydrogenation, which straightens the fatty acid tails. However, this process can lead to the formation of trans fats, which are unhealthy. The introduction of Olestra, a synthetic fat that passes through the digestive system undigested, is discussed, along with its initial adverse effects and subsequent refinement. Phospholipids, with their charged heads and uncharged tails, are described as forming the basis of cell membranes, which are crucial for regulating the passage of substances into and out of cells. Cholesterol's role in maintaining membrane fluidity and integrity across temperature changes is also explained, highlighting the importance of dietary lipids for energy and cell membrane formation.

Keywords

💡Lipids

Lipids are a broad group of organic compounds that include fats, waxes, sterols, fat-soluble vitamins, monoglycerides, diglycerides, triglycerides, and phospholipids. In the context of the video, lipids are primarily discussed as fats, emphasizing their role as a source of energy and structural component of cell membranes. The script explains that lipids, specifically triglycerides found in butter and olive oil, are composed of a glycerol head and three fatty acid tails, which store energy for the body to utilize.

💡Triglycerides

Triglycerides are the most common type of lipid in the human diet and the primary form of stored energy in the body. They are made up of a glycerol molecule attached to three fatty acids. The video script describes triglycerides as the basic form of fat, with the glycerol head and fatty acid tails being central to their structure and function, as they can be broken down by enzymes for energy.

💡Fatty Acids

Fatty acids are carboxylic acids with a long aliphatic chain, which are the building blocks of lipids such as triglycerides. The script mentions that triglycerides have three 'fatty acid tails,' where the energy is stored. Fatty acids can be saturated or unsaturated, and their structure impacts the properties of the fats they compose, such as their state at room temperature.

💡Lipases

Lipases are enzymes that catalyze the hydrolysis of lipids into glycerol and fatty acids. The script explains that lipases are essential for breaking down triglycerides in the body so that the stored energy can be released and utilized. They play a crucial role in the digestion and metabolism of dietary fats.

💡Phospholipids

Phospholipids are a class of lipids that are the main structural components of all cell membranes. They have a hydrophilic (water-attracting) head containing a phosphate group and two hydrophobic (water-repelling) fatty acid tails. The video script highlights phospholipids' role in forming the cell membrane, which is vital for regulating the passage of substances into and out of cells.

💡Cholesterol

Cholesterol is a lipid found in the cell membranes of all organisms and is also produced in the liver. It plays a critical role in maintaining membrane fluidity and integrity. The script discusses cholesterol's function within the phospholipid bilayer of cell membranes, explaining how it helps to regulate the membrane's fluidity in response to temperature changes.

💡Hydrocarbons

Hydrocarbons are organic compounds consisting entirely of hydrogen and carbon. In the context of the video, hydrocarbons refer to the long chains of carbon and hydrogen found in fatty acid tails. The script points out that the energy stored in fats comes from the chemical bonds within these hydrocarbon chains.

💡Saturated Fats

Saturated fats are triglycerides in which all the fatty acid tails have single bonds between carbon atoms and are saturated with hydrogen atoms. The script explains that saturated fats are typically solid at room temperature and can have straight fatty acid tails, allowing them to pack closely together.

💡Unsaturated Fats

Unsaturated fats are triglycerides that contain one or more double bonds between carbon atoms in their fatty acid tails. The presence of double bonds introduces kinks in the tails, preventing them from packing closely together. The script notes that unsaturated fats are usually liquid at room temperature due to this structural feature.

💡Hydrogenation

Hydrogenation is the chemical process of adding hydrogen to an unsaturated compound. In the video script, hydrogenation is mentioned as the process used to convert liquid vegetable oils into solid margarine by 'straightening out' the unsaturated fatty acid tails, creating a saturated fat.

💡Olestra

Olestra is a synthetic fat substitute made from sucrose linked to a varying number of fatty acids. The script describes olestra as a fat that the human body cannot digest due to the absence of the enzyme olestrase, allowing it to pass through the digestive system without being absorbed. However, it also discusses the side effects associated with olestra consumption, such as gastrointestinal issues.

Highlights

Lipids, or fats, are crucial for energy storage and cell membrane structure.

Triglycerides, composed of a glycerol head and three fatty acid tails, are a primary form of fat.

Lipases are enzymes that break down triglycerides to release energy.

Fats provide energy and form the basis of cell membranes through phospholipids.

Cholesterol within the cell membrane helps maintain fluidity and integrity.

Hydrocarbons in fatty acid tails store energy within lipids.

Saturated fats have straight fatty acid tails and are typically solid at room temperature.

Unsaturated fats contain kinked tails due to double bonds, making them liquid at room temperature.

Hydrogenation of unsaturated fats can create saturated fats like margarine.

Trans fats, a type of saturated fat, can lead to arteriolosclerosis and are generally unhealthy.

Olestra is an artificially created fat that passes through the digestive system undigested.

Olestra can cause gastrointestinal issues and nutrient loss.

Phospholipids have a phosphate head and form cell membranes, regulating substance transport.

Cholesterol's role is to stabilize cell membranes against temperature changes.

Dietary lipids are necessary for energy and cell membrane formation.

The speaker enjoys In-N-Out burgers but acknowledges the potential health risks of trans fats.

Transcripts

Hi. It's Mr. Andersen and in this podcast I'm going to talk about lipids

or the fats. The fat that's found in butter or the fat that's found in olive oil is what

we call a triglyceride. It's basically going to have a head, a glycerol head and then it'g

going to have three fatty acids tails. And that's where the energy is. And so when we

eat fat we can break it down. We have enzymes called lipases that are able to break that

down and then we can get energy from it. And that's been very important. We can store energy

in fats inside our body and then we can burn them when we need them. But don't forget that

fats in addition to providing energy also provide the surroundings. And so the cell

membrane that goes around every cell is made up of phospholipids. And the cholesterol is

found within the phospholipid by layer and that maintains the fluidity of the cell. And

so lipids are incredibly important. But where does the energy come from? That comes from

the hydrocarbons. And so if you look at those fatty acid tails it's essentially a carbon

attached to a carbon to a carbon to a carbon to a carbon . . . and then it has hydrogen

around the outside of it. And so we call that a hydrocarbon. And there's energy in those

bonds. And so gasoline burning out of control or the paraffin wax that's burning in a candle

is a hydrocarbon. There's a lot of energy between those carbon hydrogen bonds. And so

there's also a lot of energy found in butter or in olive oil. It's in the bonds between

the carbon and the hydrogen. And so let's start with a triglyceride. So this is a basic

fat. The head up here is going to be called the glycerol head and then this is going to

be the fatty acid tails that go down the end. And so fatty acid tail has so much carbon

and hydrogen in it that on this diagram we don't even draw them. Each of these points

represents a carbon, a carbon, a carbon. And then right here we're going to have two hydrogen

bonds or two hydrogens bonded to each of those carbons. And so you can see that there's a

huge amount of energy locked within that triglyceride and we can get that out through cellular respiration.

But know this. Those tails can come in two different forms. We can have what are called

saturated tails. A saturated tail is going to have hydrogen all the way around the outside.

And if you have hydrogen all the way around the outside then you're going to be saturated

with hydrogen. And if you're a saturated fat you're going to be a straight fat. And so

a triglyceride is going to have three of these fatty acid tails and the glycerol head, but

if it is saturated all of those are going to be straight. And if they're all straight

they can pack up on top of other triglycerides. And so saturated fats are normally going to

be a solid at room temperature. What happens if you don't have hydrogen all the way around

the outside? You're going to form these double bonds in here. If you have double bonds basically

what that does is it puts a bend in your tail. And so you're going to have a kinky tail.

And so if you're a saturated fat, you're going to look like this. If you're an unsaturated

fat you're going to look like this with kinky tails. And the kinky tails can't quite pack

together. And so normally fats that are unsaturated are going to be a liquid at room temperature.

Now humans have figured out how to take, for example, vegetable oil, which is a unsaturated

fat or it's going to be a liquid at room temperature and we can bubble hydrogen through it. We

can straighten out those tails and we can make a saturated fat called margarine that's

going to be a solid at room temperature. We've transformed this fat and if you know anything

about fats those saturated fats are the ones that are least best for us and can lead to

arteriolosclerosis, especially trans fats. Example then of how we've tried to get around

this. And this is a somewhat funny story. This is olestra. Olestra is a fat that was

made by humans. And so basically what they did us took a normal triglyceride but they

built it around a sucrose, so they built it around a sugar. And so instead of having just

three of these fatty acid tails they had sometimes eight, sometimes ten. Sometimes even more.

What's neat about that is that when you go through your digestive system we don't have

olestrase. We don't have an enzyme that can break that down and so the olestra moves right

through our digestive system. So it's a fat that feels like a fat, tastes like a fat but

it doesn't make us fat. And so Wow chips were introduced I think in the 1990s and had this

olestra in it. Basically what happened is when people started eating these Wow chips,

they got incredibly sick. They got cramping and they had to put a warning label on the

outside that it can lead to loose stools, and it pulls vitamins outside of your body.

They've kind of refined this since then and so there's not a lot of these adverse reactions.

I think Pringles light chips still contain olestra in it, but we're tricking our body,

because our body doesn't have those enzymes. Now I also said there are two more important

lipids. The first one's called phospholipids. Phospholipids are going to have, you can see,

two fatty acid tails, but they're going to have a head that contains a phosphate group.

That phosphate group is going to have a negative charge. And so normally if we were to pour

oil into water it's going to separate. And the reason why is that fats are non polar.

They don't have a charge. But what's neat about phospholipids is that they have a head

that is going to have a negative charge and then they have the tails that are uncharged.

And so if you just throw a bunch of phospholipids in water they'll form these spheres, micelles,

or they'll form these spontaneous membranes. And so the cell membranes of all cells are

made up of phospholipids. And so bacteria, archaea, eukarya, plants, animals, fungi,

we all have cell membranes. And those membranes are made up of phospholipids. They regulate

what gets in and out a cell. Cholesterol is going to maintain the fluidity of the membrane.

And so this cell membrane right here is made up of phospholipids. Those phospholipids are

constantly moving back and forth and that's important because it allows things like oxygen

to get in and carbon dioxide to get out. But if the cell gets heated up those phospholipids

tend to fall apart. And if it get's really cold they'll crowd together and so the function

of cholesterol is to grab onto those fatty acid tails and hold them together when it

gets too cold but keep them apart . . . or hold them together when they get to warm and

keep them apart when they get too cold. And so cholesterol is important at maintaining

that integrity of the cell membrane. And you can see cholesterol in this diagram right

here. We can build it in each of our cells and we have to build it in our cells, but

we have to get a little bit of it in our diet. And so we need lipids in our diet. If we don't

have lipids we can't get energy and more importantly we can't make our cell membranes. However,

today everybody's getting the fat they need. This is my favorite place to eat when I go

to California because we don't have them in Montana. This is In-N-Out burger. I love the

taste of a big burger from In-N-Out. The lipids are great but there's probably too much trans

fats in there. It's not good for me and could lead to heart disease. But for now I'm going

to keep eating them. So that's lipids, that's fat and I hope that was helpful.