Nutrition Chapter 5 Quiz

Questions and Answers

What are lipids?

Lipids are a category of compounds that contain carbon, hydrogen, and oxygen that are hydrophobic.

Remember, hydrophobic means what?

Water fearing.

"Fat" is the common name for just one type of lipid. Which one?

Triglycerides.

What are four functions of fats in foods?

<ol> <li>Fats provide a flaky texture to baked goods. 2. Fats make meat tender. 3. Fat provides flavor and aroma. 4. Fat contributes to satiety.</li> </ol> Signup and view all the answers

What are four functions that fats and other lipids perform in the body?

Energy storage, insulation, transport of protein in blood, cell membrane structure. Signup and view all the answers

What are three types of lipids found in foods and in your body?

Triglycerides, phospholipids, and sterols. Signup and view all the answers

What is a fatty acid?

A fatty acid is the basic unit of triglycerides and phospholipids. Signup and view all the answers

What are fatty acids made of?

Fatty acids are made of chains of carbon and hydrogen atoms with an acid group at the end, which is COOH. Signup and view all the answers

How many different fatty acids are there and how do they vary?

There are over 20 different fatty acids. They can vary in the length of the chain, whether the carbons have double or single bonds between them, and the total number of double bonds. Signup and view all the answers

If all carbons in a fatty acid are bonded to hydrogen, then what kind of fatty acid is that?

That's a saturated fatty acid. Signup and view all the answers

Are saturated fatty acids solid at room temperature?

True Signup and view all the answers

What's an example of a saturated fat? How many carbons does it have? And what foods is it found in?

Stearic acid has 18 carbons and is found in chocolate and in the fatty part of meat. Signup and view all the answers

If there's one or more double bond between carbons, then what kind of fatty acid is that?

An unsaturated fatty acid. Signup and view all the answers

Are unsaturated fats less saturated with hydrogen and liquid at room temperature?

True Signup and view all the answers

What is a monounsaturated fatty acid?

A monounsaturated fatty acid has just one carbon double bond in the chain. Signup and view all the answers

What's an example of a monounsaturated fat? How many carbons does it have? What food is it found in?

Oleic acid has 18 carbons and is found in olive oil. Signup and view all the answers

What's it called when there's more than one double bond between carbons?

Polyunsaturated fatty acids. Signup and view all the answers

What are two examples of polyunsaturated fatty acids? Where is one of them found?

Two examples of polyunsaturated fatty acids are linoleic acid and alpha-linolenic acid. Linoleic acid is found in soybean oil. Signup and view all the answers

Why are linoleic acid and alpha-linolenic acid considered "essential" fatty acids?

Because your body needs them but can't make them, so they must be consumed. Signup and view all the answers

What are triglycerides made of?

Triglycerides are made of three fatty acids connected to a glycerol backbone. Signup and view all the answers

What is the glycerol backbone made of?

Carbon, hydrogen, and an alcohol group (OH). Signup and view all the answers

What is the most common lipid found in foods and in the body, that is referred to as fat?

Triglycerides. Signup and view all the answers

Do phospholipids have a glycerol backbone just like triglycerides?

True Signup and view all the answers

How many fatty acids are attached to the glycerol backbone of a phospholipid?

Two. Signup and view all the answers

What else does a phospholipid have besides a glycerol backbone and two fatty acids?

A phosphate group. Signup and view all the answers

What is the head of the phosphate group?

Phosphorus. Signup and view all the answers

Is the phosphorus head of the phosphate group hydrophobic or phillic?

False Signup and view all the answers

What is the tail of a phospholipid made of?

Two fatty acids. Signup and view all the answers

Are the fatty acids tails, hydrophobic, or hydrophillic?

False Signup and view all the answers

What is a cell membrane made of?

A phospholipid bilayer. Signup and view all the answers

What is the major phospholipid in the cell membrane?

Lecithin. Signup and view all the answers

What else is lecithin used for in foods?

Lecithin is used as an emulsifier. Signup and view all the answers

What does lecithin do in salad dressings?

Lecithin keeps oils and water mixed together. Signup and view all the answers

What are sterols made of?

Four connecting rings of carbon and hydrogen. Signup and view all the answers

What's an example of a sterol?

Cholesterol. Signup and view all the answers

Does cholesterol play an important role in cell membrane structure?

True Signup and view all the answers

Is cholesterol a precursor to important compounds in the body?

True Signup and view all the answers

Why is it not necessary to consume cholesterol in your diet?

Because the body makes all the cholesterol it needs. Signup and view all the answers

What's the enzyme in your mouth that plays a minor role in breaking down some fat?

Lingual lipase. Signup and view all the answers

What's the enzyme in the stomach that breaks down some fat?

Gastric lipase. Signup and view all the answers

What does gastric lipase break down the fat into?

Into a fatty acid and a diglyceride. Signup and view all the answers

What is a diglyceride?

The remnant of fat digestion when only two fatty acids are left joined to the glycerol backbone. Signup and view all the answers

Where does the majority of fat digestion occur?

In the small intestine. Signup and view all the answers

What is the enzyme released from the pancreas that continues to break down fat?

Pancreatic lipase. Signup and view all the answers

Pancreatic lipase breaks down fat into what?

Two fatty acids and a monoglyceride. Signup and view all the answers

What is a monoglyceride?

The remnant of fat digestion when only one fatty acid is left joined to the glycerol backbone. Signup and view all the answers

Does fat mix well with the watery fluids in the G.I. tract?

False Signup and view all the answers

What is needed to help the fat mix with the watery fluids?

Bile and bile acids. Signup and view all the answers

Remember, bile is made in the liver and stored where?

In the gallbladder. Signup and view all the answers

What do the bile acids do to aid fat digestion?

They emulsify, or break up, fat globs into smaller fat globs. Signup and view all the answers

Are smaller globs of fat more easily broken down by pancreatic lipase?

True Signup and view all the answers

What are monoglycerides and fatty acids packaged with, that's found in bile?

Lecithin. Signup and view all the answers

When the monoglycerides and fatty acids are packaged with lecithin, what is created?

A micelle. Signup and view all the answers

What are micelles?

Small transport carriers that travel out of the small intestine and through the intestinal cells. Signup and view all the answers

What determines what happens next?

The length of the fatty chain acid. Signup and view all the answers

Can short chain fatty acids enter into the bloodstream directly?

True Signup and view all the answers

Once the short-term fatty acids enter the bloodstream, where do they go?

To the liver. Signup and view all the answers

Can long chain fatty acids enter the bloodstream directly?

False Signup and view all the answers

Where do the long chain fatty acids go?

Into the lymph. Signup and view all the answers

What helps the long chain fatty acids enter the lymph?

Transport carriers. Signup and view all the answers

Do the long chain fatty acids have to be reformulated into a fat within the wall of the intestines as they are absorbed?

True Signup and view all the answers

But, the reformulated fat isn't water soluble, so they have to be packaged inside something. What is it?

Lipoproteins. Signup and view all the answers

So, a lipoprotein is a fat carrier?

True Signup and view all the answers

What's one example of a lipoprotein?

A chylomicron. Signup and view all the answers

Where do chylomicrons carry the digested fat?

Through the lymph and into the bloodstream. Signup and view all the answers

What are three other lipoproteins that the liver makes?

Very low density lipoproteins (VLDL's), low density lipoproteins (LDL's), high density lipoproteins (HDL's). Signup and view all the answers

What do VLDL's deliver to the cells?

Fat. Signup and view all the answers

What do LDL's do?

They deposit cholesterol on the walls of the arteries. Signup and view all the answers

What do HDL's do?

They remove cholesterol from the body and deliver it to the liver for excretion. Signup and view all the answers

Which lipoprotein is considered the bad cholesterol carrier?

LDL. Signup and view all the answers

Which lipoprotein is considered the good cholesterol carrier?

HDL. Signup and view all the answers

How many calories per gram does fat provide?

9 calories per gram. Signup and view all the answers

How many calories per gram do carbs and protein provide?

4 calories per gram. Signup and view all the answers

What else does glucagon promote the release of at the same time?

Fat from our fat cells. Signup and view all the answers

What is fat needed for in the absorption of fat-soluble vitamins like A, D, E, and K?

Yes. Signup and view all the answers

What is a carotenoid?

A compound that has anti-oxidant compounds. Signup and view all the answers

What does fat insulate?

Your whole body. Signup and view all the answers

What does fat cushion?

Bones, organs, and nerves. Signup and view all the answers

What are two important things about cholesterol?

Cholesterol is part of the cell membrane and is a precursor for vitamin D, bile acids, and sex hormones. Signup and view all the answers

What are two essential fatty acids?

Linoleic acid and alpha-linolenic acid. Signup and view all the answers

Linoleic acid is also called what?

Omega 6 fatty acid. Signup and view all the answers

Alpha-linolenic acid is also called what?

Omega 3 fatty acid. Signup and view all the answers

What is the function of linoleic acid?

It helps decrease inflammation and helps decrease blood clotting. Signup and view all the answers

What is alpha-linolenic needed for?

Healthy cell membranes of nerves and retina. Signup and view all the answers

Are both essential fatty acids healthy for your heart?

True Signup and view all the answers

Are the essential fatty acids saturated, unsaturated, monounsaturated, or ______?

polyunsaturated Signup and view all the answers

What is the current AMDR recommendation of how much fat should be consumed?

20-35% of daily calories. Signup and view all the answers

How many more calories does fat have compared to carbs and proteins?

Twice the calories. Signup and view all the answers

For heart health, what % or less of calories should come from saturated fats?

10% or less. Signup and view all the answers

What % of your total calories should come from linoleic acid?

Between 5-10%. Signup and view all the answers

Study Notes

Lipids Overview

Lipids comprise carbon, hydrogen, and oxygen, and are hydrophobic (water-fearing).
Triglycerides, the common name for fats, represent one type of lipid.

Functions of Fats

Fats enhance the texture of baked goods and tenderize meat.
They contribute to flavor, aroma, and satiety.
In the body, lipids serve key functions, including energy storage, insulation, protein transport in blood, and cellular structure.

Fatty Acids

Fatty acids are the building blocks of triglycerides and phospholipids, consisting of carbon and hydrogen chains with a terminal acid group (COOH).
Over 20 distinct fatty acids exist, differing in chain length, bond type (single or double), and total number of double bonds.

Saturated vs. Unsaturated Fats

Saturated fatty acids contain no double bonds and are solid at room temperature, exemplified by stearic acid (18 carbons) found in chocolate and meat.
Unsaturated fatty acids have one or more double bonds, making them less saturated with hydrogen and often liquid at room temperature.

Types of Fatty Acids

Monounsaturated fatty acids have one double bond (e.g., oleic acid with 18 carbons found in olive oil).
Polyunsaturated fatty acids, with multiple double bonds, include linoleic acid (found in soybean oil) and alpha-linolenic acid.

Essential Fatty Acids

Linoleic and alpha-linolenic acids are essential, meaning they must be obtained from the diet as the body cannot produce them.

Triglycerides and Phospholipids

Triglycerides, the most common lipid, consist of three fatty acids attached to a glycerol backbone made of carbon, hydrogen, and an alcohol group (OH).
Phospholipids also contain a glycerol backbone but have two fatty acids and a phosphate group.

Cell Membrane Structure

The cell membrane is made of a phospholipid bilayer with hydrophilic phosphate heads and hydrophobic fatty acid tails.
Lecithin, a key phospholipid, acts as an emulsifier in food, helping to mix oils and water.

Digestion of Fats

Fat digestion begins in the mouth with lingual lipase and continues in the stomach with gastric lipase, breaking fats into fatty acids and diglycerides.
Most fat digestion occurs in the small intestine, where pancreatic lipase further processes fats into monoglycerides and fatty acids.

Role of Bile and Micelles

Bile acids, produced in the liver and stored in the gallbladder, emulsify fats, facilitating digestion by pancreatic lipase.
Monoglycerides and fatty acids combine with lecithin to form micelles, which transport fats through intestinal cells.

Absorption of Fatty Acids

Short-chain fatty acids enter the bloodstream directly, while long-chain fatty acids go into the lymph and require transport carriers.
Long-chain fatty acids must be reformulated into fats packaged in lipoproteins (e.g., chylomicrons) for transport into the bloodstream.

Cholesterol and Lipoproteins

Cholesterol, a type of sterol, is crucial for cell membranes and acts as a precursor for vitamin D and hormones.
The liver produces various lipoproteins: VLDLs carry fat to cells, LDLs deposit cholesterol in arteries (the "bad" cholesterol), and HDLs remove cholesterol for excretion (the "good" cholesterol).

Energy Supply and Functions of Fats

Fats provide 9 calories per gram, compared to 4 calories per gram for carbohydrates and proteins.
Dietary fat is essential for absorbing fat-soluble vitamins (A, D, E, K) and carotenoids, and plays a role in thermoregulation and cushioning organs.

Essential Fatty Acids and Health

Linoleic acid (omega-6) decreases inflammation and blood clotting, while alpha-linolenic acid (omega-3) supports healthy cell membranes.
Both essential fatty acids are essential for heart health and are polyunsaturated.

Daily Fat Intake Recommendations

AMDR recommendations suggest that 20-35% of daily calories should come from fat.
For heart health, saturated fats should account for 10% or less of total caloric intake, while linoleic acid should comprise 5-10% of daily calories.

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Description

Test your knowledge on key concepts from Chapter 5 of Nutrition, including lipids and their functions in food. This quiz explores important definitions and helps reinforce your understanding of fat and its characteristics.