[2] Class 1-Lipids-Agbas

Question 1

What is water insoluble but highly soluble in organic solvents?

Answer 1

Lipids

Question 2

What is the key constituent of Lipids?

Answer 2

Fatty acids

Question 3

What part of the lipid is responsible for hydrophobic properties?

Answer 3

Fatty acids

Question 4

What makes lipids amphipathic?

Answer 4

Hydrophobic fatty acid tail

Hydrophilic phosphate head group

Question 5

Unsaturated double bond in FA tail contributes 2 things:

Answer 5

Allows cholesterol to be in between 2 FA’s and provides fluidity to the membrane

Question 6

Proteins are modified by what attachment that allows them to target membranes

Answer 6

Covalent attachment of FA’s

Question 7

Functions of FA’s:

Answer 7

Membrane component
Store fuel as triacylglycerols (TAG)
Derivatives serve as hormones, signal molecules, and Intracellular messengers

Question 8

How do you number carbons in FA chain?

Answer 8

Starting at carboxyl terminus
OR
Omega begin counting at methyl carbon at distal end of the chain

Question 9

Carbons 2 and 3 of fatty acid

Answer 9

alpha and beta

Question 10

How to name fatty acids?

Answer 10

E changes to -oic.
Double bonds change
-ane to en to dien to trien

Question 11

18:0
Vs
18:2

Answer 11

18 Carbon FA w/ no double bonds and :2= 2 double bonds

Question 12

Fatty acids usually contain an _____ number of Carbon atoms, typically between ____ and ____ carbons

Answer 12

EVEN ; 14 and 24

Question 13

What length FA’s are most common?

Answer 13

16- and 18-

Question 14

Configuration of the double bonds in most unsaturated FA’s is

Answer 14

Cis

Question 15

FA’s are _______ at physiological pH

Answer 15

Ionized

Question 16

What determines the properties of fatty acids?

Answer 16

Length of hydrocarbon chain

Degree of saturation

Question 17

Relate melting point and unsaturated FA vs. saturated FA

Answer 17

Unsaturated has lower melting point…doesn’t allow for tight packing

Question 18

How is melting point affected when saturated FA increase w/ chain length?

Answer 18

M.P increases w/ increased chain length d/t more tight packing is possible w/ more carbon groups

Question 19

Name the 3 essential FA’s:

Answer 19

Linoleate
Linolenate
Arachidonate

Question 20

Which EFA is not really a EFA?

Answer 20

Arachidonate

Can be manufactured by linolenate

Question 21

What type of bond is found in archea that allows life in extreme environments? Why?

Answer 21

Ether bonds; they’re more resistant to hydrolysis

They also have branched and saturated hydrocarbons- resistant to oxidation

Question 22

3 major membrane lipids:

Answer 22

Phospholipids
Glycolipids
Cholesterol

Question 23

2 types of phospholipids

Answer 23

Phosphoglyceride

Sphingomyelin

Question 24

Major glycolipid:

Answer 24

Cerebroside

Question 25

What are the 4 components of a phospholipid?

Answer 25

1 FA 2 A backbone 3 A phosphate 4 An alcohol

Question 26

Which properties allow phospholipids to interact w/ the environment?

Answer 26

Hydrophilic properties of the phosphate and alcohol groups.

Question 27

Name the simplest phosphoglyceride:

Answer 27

Phosphatidate OR Diacylglycerol 3-phosphate

Question 28

What process is Phosphatidate or diacylglycerol 3-phosphate involved in?

Answer 28

It is a key intermediate in the biosynthesis of other phosphoglycerides

Question 29

Is there a lot of Phosphatidate in membrane?

Answer 29

No only small amounts of phosphatidate are present in membranes

Question 30

What is derived from Phosphatidate?

Answer 30

Phosphoglycerides

Question 31

Phosphoglyceride important for memory and cognition

Answer 31

Phosphatidylserine

Question 32

Phosphoglyceride that it's major constituent of cell membrane and pulmonary surfactant

Answer 32

Phosphatidylcholine

Question 33

Phosphoglyceride composing 25% of all phospholipids and are found, particularly in humans, in nervous tissue such as the white matter of the brain

Answer 33

Phosphatidylethanolamine

Question 34

Phosphoglyceride important for signaling and other functional activities in eukaryotic cell

Answer 34

Phosphatidylinositol

Question 35

Phosphoglyceride that is important component of inner mitochondrial membrane

Answer 35

Diphosphatidylglycerol

Question 36

Amino group replaces a fatty acid component of phosphoglyceride...other fatty acid is unsaturated c-18 Amino Alcohol

Answer 36

Sphingosine

Question 37

Sphingosine + FA

Answer 37

Ceramide

Question 38

Ceramide + phosphorylcholine

Answer 38

Sphingomyelin

Question 39

Ceramide + monosaccharides

Answer 39

Cerebrosides

Question 40

Ceramide + oligosaccharides

Answer 40

Globoosides

Question 41

Ceramide oligosaccharides + NANA

Answer 41

Gangliosides

Question 42

Phospholipid w/ sphingosine as backbone w/ amide bonded FA and phosphorylcholine group

Answer 42

Sphingomyelin

Question 43

Where is sphingomyelin found? And what purpose does it serve?

Answer 43

Animal cell membranes in myelin sheath that surrounds some nerve cell axons It provides electrical insulation for nerve transmission

Question 44

- Sugar-containing lipids - Derived from sphingosine - Differ from sphingosine d/t unit linked to OH- grp of backbone

Answer 44

Glycolipids

Question 45

Glycolipids sugar moiety face intra/extracellular?

Answer 45

Extracellular. It is involved in cell to cell interactions

Question 46

- The simplest glycolipid - Contains single sugar residue - Also called monoglycosylceramides

Answer 46

Cerebrosides

Question 47

Function of Cerebrosides:

Answer 47

Important components in animal muscle and nerve cell membranes

Question 48

A steroid, present in eukaryotes [not most porkaryotes] Built from 4 fused saturated hydrocarbon rings Classified as sterol b/c of OH- grp. And branched aliphatic side chain o 8-10 C atoms at C-17.

Answer 48

Cholesterol

Question 49

Which Carbon has the OH-grp in cholesterol?

Answer 49

Carbon 3

Question 50

Scientific name of cholesterol

Answer 50

Cyclopentanoperhydrophenanthrene ring system

Question 51

Most abundant steroid in animals Major component of eukaryotic plasma membrane

Answer 51

Cholesterol

Question 52

Cholesterol orientation in membrane?

Answer 52

Parallel to FA chains of the phospholipids, and the hydroxyl group interacts w/ the nearby phospholipid head group.

Question 53

Cholesterol is absent in:

Answer 53

Some Intracellular membranes And Prokaryotes

Question 54

Metabolic precursor of steroid hormones:

Answer 54

Cholesterol

Question 55

Key components of lipids:

Answer 55

FA's