L4-Lipids

Question 1

What are considered part of the non-membrane lipids?

Answer 1

• Fatty acids
• Triaclyglycerols
• Steroids
• Cholesterol esters

Question 2

What are considered part of the membrane lipids?

Answer 2

• glycerolphospholipids
• sphingolipids
• cholesterol

Question 3

What does a fatty acid look like?

Answer 3

simplest form.

• polar, carboxylic acid head
• nonpolar, methyl group tail

Question 4

What type of fatty acids is the omega naming system used for?

Answer 4

Long-chained polyunsaturated fatty acids

Question 5

What are some examples of saturated fatty acids?

Answer 5

animal meats, butter, whole milk, tropical plant oils

- stearic acid

Question 6

What are some examples of monounsaturated fatty acids?

Answer 6

olive oil, canola oil, nuts

-oleic acid

Question 7

What are some examples of polyunsaturated fatty acids?

Answer 7

fatty fish, seeds, nuts, grains, veggies

-omega 3&6

Question 8

What is the formation of trans fatty acids?

Answer 8

structurally similar to saturated fatty acids even with a double bond
- double bond H atoms are across from each other

Question 9

What are the two essential fatty acids?

Answer 9

Omega 3 and omega 6
-Omega 3 is a precursor for growth and development (linolenic acid)
-Omega 6 is a precursor for arachoidonic acid
(linoleic acid)

Question 10

Phytanic acid is what type of lipid?

Answer 10

A branched fatty acid
Contains a methyl group on the third carbon
This methyl means it is broken down through a-oxidation

Question 11

What is caused by a deficiency in a-hydroxylase?

Answer 11

Refsum disease

• phytanic acid accumulates in the blood and tissues which causes neuronal damage
• treat with a diet low in phytanic acid

Question 12

What is the storage form of fatty acids called?

Answer 12

Triaglycerides

Question 13

What are the components of TAGs?

Answer 13

• 3 activated fatty acids (as fatty acylCoA)

- 1 glycerol

Question 14

What is the basic structure of a steroid?

Answer 14

A tetracyclic ring structure

Question 15

What is the basic structure of a cholesterol ester?

Answer 15

The polar group of cholesterol is esterified to a fatty acid

-> non polar molecule

Question 16

What are the three types of amphipathic molecules?

Answer 16

glycerolphospholipids, sphingolipids, cholesterol

Question 17

What are the hydrophobic and philic regions of glycerolphospholipids?

Answer 17

phobic- 2 long chain fatty acids

philic-phosphate group+alcohol

Question 18

What are the phobic and philic regions of sphingomyelins

Answer 18

phobic- ceramide ( fatty acid+sphingosine)

philic-phosphate group plus choline

Question 19

What are the phobic and philic regions of glycosphingolipids?

Answer 19

phobic- ceramide (fatty acid+sphingosine)

philic- carbohydrate group

Question 20

What are the phobic and philic regions of cholesterol?

Answer 20

phobic- rigid steroid ring + nonpolar tail

philic- OH- group

Question 21

What enzymes produced in the mouth and stomach breakdown fats?

Answer 21

lingual lipase and gastric lipase

—-> primary target are short chain FFA (

Question 22

Lipids stimulate the secretion of what from the small intestine?

Answer 22

CCK and secretin

Question 23

What is the function of CCK?

Answer 23

Delays gastric emptying, promotes satiety

-stimulate the release of bile sale and pancreatic enzymes

Question 24

What is the function of secretin?

Answer 24

Stimulates the pancreas to release HCO3-

—-> neutralizes acidic chyme

Question 25

What is the first step of emulsification?

Answer 25

spraying chyme through narrow pyloric sphincter

Question 26

How do bile salts function?

Answer 26

They stabilize the lipid droplets in solution and prevent them from coalescing

Question 27

Pancreatic lipase break TAGs down into what?

Answer 27

a monoglyceride and 2 fatty acids

Question 28

What are mixed micelles formed of?

Answer 28

disk shaped clusters of amphipathic lipids

-bile salts make up the edges of the “coin”

Question 29

How do micelles transport lipids to the enterocytes?

Answer 29

They bump into the border and dump their contents into the enterocytes but remain in the lumen to be recycled

Question 30

How are TAGs and Cholesterol esters transported?

Answer 30

They must be reassembled and packaged into chylomicrons and enter the lymphatic system

Question 31

What are chylomicrons?

Answer 31

Lipid droplets composed of monolayer amphipathic lipids
- the largest of the lipoproteins
-enter the blood stream 1-2 hours after a meal
(the lymphatic system drains into the blood at the thoracic duct)

Question 32

How to short and medium chain FFa enter the blood stream?

Answer 32

They are transported to the enterocyte as is. They bind to albumin and go directly to the liver for energy metabolism

Question 33

What is steatorrhea?

Answer 33

increased lipid in the feces

Question 34

What are come causes for lipid malabsorption?

Answer 34

• low bile salts
• low pancreatic enzymes
• decrease in absorption

Question 35

What is Olestra?

Answer 35

made from sucrose to which fatty acids have been esterified

-heat stable, not digested, lost in stool with other fat soluble nutrients

Question 36

What is Simplesse?

Answer 36

Made from microparticulated proteins from milk and eggs

• not heat stable so used in ice cream
• half the calories of fat

Question 37

What is orlistat (xenical/alli)?

Answer 37

A drug for obesity

• inhibits pancreatic lipases
• fat is then lost in the stool