Biochemistry Exam 2: Lipids And Biological Membranes

Front 1

Describe characteristics of Lipids?

Back 1

Not polymeric, do aggregate, exhibit greater structural variety, largely hydrophobic, sparingly water soluble

Front 2

What are the three major cellular functions of Lipids?

Back 2

- Cellular Membranes
- Energy stores when containing hydrocarbon chains
-Intra and Inter cellular signaling events

Front 3

What are the classification groups of lipids?

Back 3

Fatty Acids, Triglycerides, Phosphoglycerides, Sphingolipds, Steroids, other lipids

Front 4

Describe Fatty Acids.

Back 4

They are carboxylic acids with long chain hydrocarbon side groups

Front 5

Describe Triglycerides.

Back 5

Fatty Acid esters of glycerol, energy reservoirs

Front 6

Describe Phosphoglycerides.

Back 6

biological membrane lipid

Front 7

Sphingolipids -

Back 7

Also major membrane lipid

Front 8

Describe Steroids.

Back 8

Mostly of eukaryotic origin, derivatives include sex hormones and cholesterol

Front 9

What are included in other lipids?

Back 9

Vitamins and cofactors

Front 10

What are hte predominant fatty acid residues? Which ones are uncommon?

Back 10

C16 and C18; <C14 and >C20

Front 11

Over half fatty acids are _______.

Back 11

unsaturated. Often polyunsaturated

Front 12

Where is the first double bond usually in fatty acid?

Back 12

between C9 and C10 counting from Carboxylic Acid C atom

Front 13

In polyunsaturated fatty acids. Double bond tends to occur at every _____ Carbon atom.

Back 13

Third

Front 14

What are two important classes of polyunsaturated fatty acids based on nomenclature?

Back 14

w-3 fatty acids and w-6 fatty acids; w(omega) end of chain

Front 15

How are linoleic acid and alpha linoleic acid different?

Back 15

alpha linoleic acid is w-3, and linoleic acids is w-6

Front 16

Describe saturated fatty acids.

Back 16

They are fully reduced or saturated with H, highly flexible with wide range of conformations, relatively free rotation around C-Cbonds

Front 17

Why are unsaturated fatty acids less rotational?

Back 17

Double bonds are almost always cis so this puts rigid 30 degree bend in Hydrocarbon chain

Front 18

________fatty acids pack together than _____________.

Back 18

Saturated, unsaturated

Front 19

Where are triglycerides found?

Back 19

Fats and oil in plants and animals

Front 20

Describe triglycerides.

Back 20

They are non-polar water insoluble fatty acid triesters of glycerol and serve as energy stores.

Front 21

What is the most abundant class of lipids?

Back 21

Triglycerides

Front 22

How do triglycerides differ?

Back 22

According to identity and placement of fatty acids on glycerol

Front 23

How are triglycerides named?

Back 23

Placement of glycerol moiety, ate fatty acid ending replaced by oyl ending, use 1,2,3 to indicate position

Front 24

Describe difference between plant oils and animal fats.

Back 24

Plant oils tend to be unsaturated with lower melting point while fats tend to be more saturated with higher melting points. Fats are solids at room temp and oils are liquid at room temp.

Front 25

How are fats so efficient in metabolic energy storage?

Back 25

They yield more energy/unit mass on oxidation. Storeod as anhydrous form whereas glycogen binds 2times weight of water. It provides 6 times metabolic energy as equal weight hydrated glycogen.

Front 26

What are adipocytes?

Back 26

Fat cells specialized for synthesis and storage of triacylglycerols

Front 27

Where is adipose tissue?

Back 27

Most abundant in subcutaneous layers and abdominal activity

Front 28

What is major lipid component of biological membranes?

Back 28

Glycerophospholipids

Front 29

Why are glycerophospholipids considered amphiphilic?

Back 29

They have nonpolare aliphatic hyderocarbon tails and polar phosphorylX heads

Front 30

For glycerophospholipds, where are most common head groups derived from?

Back 30

Polar alcohols

Front 31

What glycerophospholipid is an important lung surfactant?

Back 31

Lecithin