CLASSIFICATIONS, ENERGY-STORAGE LIPIDS: TRIACYLGLYCEROLS (+ Fats and Oils)

Question 1

Two common methods exist for sub-classifying lipids into families for the purpose of study.

Answer 1

a. biochemical function of a lipid as the basis for classification
b. based on whether or not a
lipid can be broken down into smaller units through basic hydrolysis

Question 2

A hydrolysis reaction that occurs in basic solution is called a _________.

Answer 2

saponification reaction

Question 3

BASED ON BIOCHEMICAL FUNCTION, LIPIDS ARE DIVIDED INTO FIVE CATEGORIES

Answer 3

● Energy-storage lipids (triacylglycerols)
● Membrane lipids (phospholipids,
sphingoglycolipids, and cholesterol)
● Emulsification lipids (bile acids)
● Messenger lipids (steroid hormones and
eicosanoids)
● Protective-coating lipids (biological
waxes)

Question 4

BASED UPON WHETHER OR NOT SAPONIFICATION
OCCURS WHEN A LIPID IS PLACED IN BASIC AQUEOUS SOLUTION, LIPIDS ARE DIVIDED INTO TWO
CATEGORIES:

Answer 4

a. Hydrolyzable/Saponifiable lipids
b. Nonhydrolyzable lipids

Question 5

The most widespread energy-storage material within cells is the

Answer 5

carbohydrate glycogen

Question 6

Lipids known as __________ also function within the body as energy-storage materials.

Answer 6

triacylglycerols

Question 7

Rather than being widespread, triacylglycerols
are concentrated primarily in special cells (___________) that are nearly filled with the
material.

Answer 7

adipocytes

Question 8

Adipose tissue containing these cells is found in various parts of the body:

Answer 8

under the skin, in the abdominal cavity, in the mammary glands, and around various organs.

Question 9

Triacylglycerols are __________; three ester functional groups are present.

Answer 9

triesters

Question 10

_________ are the carboxylic acids involved in
triacylglycerol formation.

Answer 10

Fatty acids

Question 11

_____ are naturally occurring mixtures of triacylglycerol molecules in which many
different kinds of triacylglycerol molecules are
present.

Answer 11

fats and oils

Question 12

A ____ is a triacylglycerol mixture that is a solid or a semisolid at room temperature (25 °C). Generally, these are obtained from animal sources.

Answer 12

fat

Question 13

An ____ is a triacylglycerol mixture that is a liquid at room temperature (25 °C). Generally, these are obtained from plant sources.

Answer 13

oil

Question 14

Fats are composed largely of triacylglycerols in which __________ fatty acids predominate.

Answer 14

saturated

Question 15

Oils contain triacylglycerols with larger amounts of
____________________ fatty acids than those in fats.

Answer 15

mono- and polyunsaturated

Question 16

_____________ fats, which are liquid at room temperature, are considered beneficial fats because they can improve blood cholesterol levels, ease inflammation, stabilize heart rhythms, and play a number of other beneficial roles.

Answer 16

unsaturated

Question 17

One of the best oils for heart health, _________ has less saturated fat than any other oil.

Answer 17

canola oil