ME03 - Lipid Significance

Question 1

Importance of Lipids

Answer 1

_fats, oils, steroids, waxes

Question 2

Common Physical proprties of Lipids

Answer 2

Relatively insoluble in water soluble in nonpolar solvents

Question 3

Important Dietary constituents

Answer 3

fat-soluble vitamins Micronutrients long chain omega-3 fatty acids

Question 4

Where are lipids stored in the body

Answer 4

Adipose Tissue

Question 5

Clinical Diseases that Involve Lipids

Answer 5

obesity, diabetes mellitus, and atherosclerosis

Question 6

Classification of Lipids

Answer 6

1. Simple lipids A. Fats- Triglycerols, Oils B. Waxes Do not have triglyceride ester of three fatty acids Fatty acid and alcohol esters 2. Complex lipids A. Phospholipids - lipid with phosphate grp Glycolipids (glycosphingolipids) - Other complex lipids - Lipoproteins 3. Precursor and derived lipids fatty acids, glycerol, steroids, other alcohols, fatty aldehydes, ketone bodies, hydrocarbons, lipid-soluble vitamins and micronutrients, and hormones

Question 7

Fatty Acids are Aliphatic Carboxylic Acids, True or False

Answer 7

TRUE

Question 8

Transport form in the plasma

Answer 8

Free Fatty Acids

Question 9

Lipids that contain no double bonds

Answer 9

Saturated, Example: Acetic Acid (CH3COOH), Butyric(4) Valeric (5) Caproic (6) Lauric (12) Myristic (14) Palmitic (16) Stearic (18)

Question 10

Lipids containing one or more double bonds

Answer 10

Unsaturated Example: Monounsaturated Polyunsaturated Eicosanoids - Eicosa (20-carbon) polyenoic fatty acids Prostanoids, Leukotrienes (LTs), Lipoxins (LXs)

Question 11

Unsaturated fatty acids has a higher melting point than saturated fatty acids

Answer 11

TRUE

Question 12

C16:0 or 16:0

Answer 12

Palmitic, No. of C = number of double bonds

Question 13

C18:2 (9,12) w-carbon (methyl carbon)

Answer 13

Linoleic acid

Question 14

C18:3 (9,12,15)

Answer 14

Linolenic acid

Question 15

What are essential Lipids

Answer 15

Linoleic acid; Linolenic Acid (ADEK)

Question 16

Essential Amino Acids needed since Linoleic and Linolenic Acid cannot be made by the human body

Answer 16

Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine + (Arginine for infants)

Question 17

Is there such thing as an essential carbohydrates?

Answer 17

NO, THERE’S NONE.

Question 18

Types of Geometric Isomerism

Answer 18

cis- If the acyl chains are on the same side of the bond (oleic acid) Double bonds in fatty acids Trans- If the acyl chains are on opposite sides (elaidic acid)

Question 19

Most naturally occuring unsaturated fatty acid

Answer 19

Unsaturated fatty acids that have CIS-DOUBLE BONDS

Question 20

Disease associated with trans and saturated fatty acids

Answer 20

Atherosclerosis

Question 21

Trans double bonds are ____________

Answer 21

Unnatural. It causes decreased fluidity (Ex. Margarine)

Question 22

Physical and Physiologic Properties of Fatty Acids

Answer 22

More saturated = More solid at body temperature Polyunsaturated= Liquid to below zero dec celsius membrane lipids| Hibernators

Question 23

What are Omega 3 Faty Acids

Answer 23

_-linolenic (ALA) - Found in plant oils eicosapentaenoic (EPA) - found in fish oil docosahexaenoic (DHA) - found in fish and algal oils

Question 24

Clinical Significance of Omega 3 Fatty Acids

Answer 24

anti-inflammatory effects promoting the synthesis of less inflammatory prostaglandins and leukotrienes cardiovascular disease Cancer Rheumatoid arthritis Alzheimer disease

Question 25

Main storage forms of fatty acids

Answer 25

Triglycerides (C1 and C3 of glyceril are not identical when viewed in three dimensions)

Question 26

Precursor of Phospholipids, Influence membranes and acts in Signalling

Answer 26

Phosphatidic Acid

Question 27

Glycerophospholipids containing choline

Answer 27

Lecithins (phosphatidylcholine) most abundant phospholipids of the cell membrane

Question 28

Why is Choline important?

Answer 28

Important in Nervous transmission, as acetylcholine, and as store of labile methyl groups

Question 29

Phospholipid that acts as surfactant

Answer 29

Dipalmitoyl Lecithin contains Type II alveolar cells preventing adherence, due to surface tension, of the inner surfaces of the lungs

Question 30

Clinical Significance of Dipalmitoyl lecithin as surfactant

Answer 30

Respiratory Distress Syndrome

Question 31

Ethanolamine or serine, respectively, replaces choline

Answer 31

\_Phosphatidylethanolamine (cephalin) and phosphatidylserine

Question 32

Plays a role in apoptosis (programmed cell death)

Answer 32

\_Phosphatidylethanolamine (cephalin) and phosphatidylserine

Question 33

Found in the outer leaflet of the cell membrane lipid bilayer, lipid rafts, and myelin sheath

Answer 33

Sphingomyelins

Question 34

Function of Sphingomyelins

Answer 34

Cell signaling and apoptosis

Question 35

Phopholipid found only in mitochondria

Answer 35

Phosphatidylglycerol

Question 36

Gives rise to Cardiolipin

Answer 36

Phosphatidylglycerol

Question 37

Alterations in functions of Phosphatidylglycerol can result to

Answer 37

heart failure and hypothyroidism and aging

Question 38

Gives rise to Lysolecithin important in the metabolism and interconversion of phospholipids found in oxidized lipoproteins

Answer 38

Lysophosphatidylcholine

Question 39

Clinical Significance of Lysophosphatidylcholine

Answer 39

Atherosclerosis

Question 40

Lipids with an attached carbohydrate or carbohydrate chain Widely distributed in every tissue of the body, particularly in nervous tissue; Occur partly in the outer leaflet of plasma membrane Contributes to Glycocalyx

Answer 40

Glycolipids

Question 41

Major glycosphingolipid of brain and other nervous tissue

Answer 41

\_Galactosylceramide

Question 42

Galactosylceramide is converted to ______ which is present in high amounts in MYELIN

Answer 42

Sulfatide

Question 43

Resembles galactosylceramide, head group is glucose rather than galactise

Answer 43

Glucosylceramide

Question 44

Complex glycosphingolipids derived from glucosylceramide

Answer 44

Gangliosides

Question 45

Function of Gangliosides

Answer 45

GM1 - Function in cell-cell recognition and communication and as receptors for hormones and bacterial toxins (cholera)

Question 46

Predominant simply glycosphingoloid of extraneural tissues

Answer 46

Glucosylceramide

Question 47

What is the precursor of Steroids

Answer 47

Cholesterol

Question 48

Precursor of large number of employed steroids includes;

Answer 48

Bile Acids, Adrenocortical Hormones, Sex hormones, Vitamin D & Cardiac Glycosides

Question 49

What is the precursor of Vitamin D

Answer 49

Ergosterol

Question 50

Not steroids Related because they are synthesized, like cholesterol from Fivecarbon isoprene units Rubber, camphor, the fat-soluble vitamins A, D, E, and K, and \_-carotene (provitamin A)

Answer 50

Polyprenoids

Question 51

Polyprenoid that has Respiratory chain in mitochondria

Answer 51

Ubiquinone

Question 52

Polyprenoid that takes part in glycoprotein synthesis

Answer 52

Dolichol

Question 53

Auto-oxidation of lipids Responsible for rancidity of foods Damage to tissues in vivo Cancer, inflammatory diseases, atherosclerosis, and aging

Answer 53

Lipid Peroxidation

Question 54

Molecules that have unpaired valence electrons Reactive oxygen species (ROS)

Answer 54

Free Radicals

Question 55

Chain reaction providing continuous supply of ROS

Answer 55

Initiation - Propagation - Termination

Question 56

2 classes of Antioxidants

Answer 56

1. Preventive antioxidants Catalase| EDTA | DTPA | Glutathione peroxidase 2. Chain-breaking antioxidants Superoxide dismutase | vitamin E

Question 57

Why are LIPIDS insoluble in water

Answer 57

Predominance of nonpolar (hydrocarbon) groups

Question 58

Part of the molecule is hydrophobic, or water insoluble; and a part is hydrophilic, or water soluble

Answer 58

AMPHIPATHIC - Micelles, Liposomes