Rapid Review Biochem, Chapter 1 (Only The Lipids Section)

Front 1

These are known as the simplest lipids, which can be oxidized to generate much of the energy needed by cells in the fasting state (excluding brain cells and erythrocytes)

Back 1

Fatty acids

Front 2

What are the only two "essential" fatty acids (MUST be supplied in the DIET)?

Back 2

1. Linoleic
2. Linolenic

Hint 2

Both start with an "L"

Front 3

In humans, most fatty acids have an ____(even or odd?) number of carbon atoms with a chain length of _____(what is the range for the chain length?) carbon atoms

Back 3

1. Even

2. 16-20

Front 4

How many carbons are there in short-chain fatty acids?

Back 4

2-4

Front 5

How many carbons are there in medium-chain fatty acids?

Back 5

6-10

Front 6

These two types of fatty acids can be directly reabsorbed in the small intestine, and they also diffuse freely into the mitochondrial matrix to be oxidized. What are they?

Back 6

1. Short chain (2-4 carbons) FAs

2. Medium chain (6-10 carbons) FAs

Front 7

How do short chain and medium chain fatty acids primarily occur in the body (as what?)?

Back 7

They occur primarily as metabolic intermediates

Front 8

How many carbons are there in Long-chain fatty acids?

Back 8

12 or more

Front 9

In what form are Long-chain fatty acids found in the body?

Back 9

As triacylglycerols (fat) and as structural lipids

Front 10

Unlike short-chain and medium-chain fatty acids, what do Long-chain fatty acids require to move from the cell cytosol into the mitochondria? (what "shuttle?")

Back 10

The carnitine shuttle

Front 11

Unsaturated fatty acids are different from saturated fattty acids because the unsaturated ones contain what?

Back 11

One or more double bonds

Front 12

Double bonds in most NATURALLY occuring fatty acids have what type of configuration? (cis or trans?)

Back 12

Cis

Front 13

What type of fatty acids are formed in the production of MARGARINE and other hydrogenated vegetable oils?

Back 13

Trans Fatty acids

Front 14

Consuming these types of fatty acids are a risk factor for atherosclerosis:

Back 14

Trans Fatty Acids

Front 15

Which vitamin deficiency can lead to hemolytic anemia? Why?

Back 15

Vitamin E deficicency, because it is a lipid soluble vitamin that acts like an antioxidant. Sometimes, oxidation of fatty acids in membrane lipids occurs, which yields breakdown products that cause membrane damage, which can lead to hemolytic anemia if Vitamin E isn't present to minimize these damaging breakdown products.

Front 16

This group of lipids are a highly concentrated energy reserve, formed by esterification of fatty acids with glycerol. What is this group of lipids called?

Back 16

Triacylglycerols (TGs)

Front 17

Triacylglycerols (TGs) can be accumulated in the body from 3 different sources. What are they?

Back 17

1. Excess fatty acids in the diet
2. Fatty acids synthesized from excess dietary carbohydrate
3. Fatty acids synthesized from excess dietary protein

Front 18

Where are triacylglycerols (TGs) stored in the body?

Back 18

Adipose cells

Front 19

What is a phosphatidic acid? What kinds of lipids are derived from phosphatidic acid?

Back 19

1. Phosphatidic acid is diacylglycerol with a poshphate group on the third glycerol carbon.

2. The group of lipids derived from these are phospholipids

Front 20

How are phospholipids named?

Back 20

They are named for their "X" group esterfied to the phosphate

Front 21

What is the chain length of the Palmitic acid? (a fatty acid)

Back 21

16

Front 22

What is the chain length of the Stearic acid? (a fatty acid)

Back 22

18

Front 23

What is the chain length of the Palmitoleic acid? (a fatty acid)

Back 23

16

Front 24

What is the chain length of the Oleic acid? (a fatty acid)

Back 24

18

Front 25

What is the chain length of the Linoleic acid? (a fatty acid)

Back 25

18

Front 26

What is the chain length of the Linolenic acid? (a fatty acid)

Back 26

18

Front 27

What is the chain length of the Arachidonic acid? (a fatty acid)

Back 27

20

Front 28

What X group is esterfied to the phosphate in the phospholipid Phosphatidylcholine?

Back 28

Choline

Front 29

What X group is esterfied to the phosphate in the phospholipid Phosphatidylethanolamine?

Back 29

Ethanolamine

Front 30

What X group is esterfied to the phosphate in the phospholipid Phosphatidylserine?

Back 30

Serine

Front 31

What X group is esterfied to the phosphate in the phospholipid Phosphatidylinositol?

Back 31

Inositol

Front 32

What X group is esterfied to the phosphate in the phospholipid Cardiolipin?

Back 32

Glycerol linked to a second phosphatidic acid

Front 33

What is another name for the phospholipid Phosphatidylcholine?

Back 33

Lecithin

Front 34

What is another name for the phospholipid Phosphatidylethanolamine?

Back 34

Cephalin

Front 35

Where is lecithin commonly found in the human body?

Back 35

In the lungs, as a part of surfactant

Front 36

The fluidity of cellular membranes correlates ______(directly or inversely?) with the melting point of fatty acids in membrane phospholipids

Back 36

Inversely (so if the melting point of the fatty acids is very high, it means that the fatty acids have to be heated up pretty high before they can begin melting, which means they are stuck together to each other pretty strongly, thus making them less fluid to begin with).

Front 37

What enzymes cleave specific bonds in phospholipids?

Back 37

Phospholipases

Front 38

These two phospholipases remove fatty acyl groups and play a role in remodeling and degradation of phospholipids

Back 38

Phospholipases A1 and A2

Front 39

Increased cytosolic CALCIUM ACTIVATES this phospholipase, causing cell membrane damange in tissue hypoxia.

Back 39

Phospholipase A2 (plays a role in remodeling and degradation of phospholipids)

Front 40

CORTICOSTEROIDS DECREASE this phospholipase's activity, thereby decreasing the release of _____, which is part of the inflammatory response (so the inflammatory response is diminished with corticosteroids).

Back 40

1. Phospholipase A2 (plays a role in remodeling and degradation of phospholipids)

2. Arachidonic acid

Front 41

This phospholipase liberates diacylglycerol (2/3 of a TG) and inositol triphosphate, two potent intracellular signals

Back 41

Phospholipase C

Front 42

This phospholipase generates phosphatidic acid from varoius phospholipids (so it just cuts out the "X" group from the phosphate group)

Back 42

Phospholipase D

Front 43

Lung surfactant, which decreases surface tension in the alveoli, contains abundant phospholipids, especially _____. (don't look at the hint)

Back 43

Phosphatidylcholine (also known as what? Look at the hint)

Hint 43

Lecithin

Front 44

What syndrome is associated with insufficient lung surfactant production in premature infants, leading to partial lung collapse?

Back 44

Respiratory distress syndrome/ Hyaline membrane disease

Front 45

What syndrome is associated with insufficient lung surfactant production in infants with diabetic mothers, leading to partial lung collapse?

Back 45

Respiratory distress syndrome/ Hyaline membrane disease

Front 46

These lipids are derivatives of ceramide, which is formed by esterification of a fatty acid with the amino group of sphingosine.

Back 46

Sphingolipids

Front 47

Where are sphingolipids mainly localized in the body (not only what organ system, but what distribution in that organ system)?

Back 47

In the white matter of the central nervous system (so disorders of sphingolipids have significant impact on neural tissue)

Front 48

Sphingolipidosis is the accumulation of sphingolipids in cells. What is the mechanism that cause sphingolipidoses? Name two diseases associated with sphingolipidosis.

Back 48

1. Hereditary defects in the lysozomal enzymes that degrade sphingolipids

2. Tay-Sachs disease and Gaucher's disease

Front 49

Sphingolipids are distinguished by the "X" group attached to the terminal hydroxyl group ceramide. What "X" group is attached in SPHINGOMYELIN?

Back 49

Phosphatidylcholine

Front 50

Sphingolipids are distinguished by the "X" group attached to the terminal hydroxyl group ceramide. What "X" group is attached in CEREBROSIDE (two possible answers)?

Back 50

Galactose or Glucose

Front 51

Sphingolipids are distinguished by the "X" group attached to the terminal hydroxyl group ceramide. What "X" group is attached in GANGLIOSIDE?

Back 51

Sialic Acid-containing oligosaccharide

Front 52

Where is Sphingomyelin, a type of sphingolipid, most commonly found inthe body (two answers)?

Back 52

In nerve tissue and the blood

Front 53

Where is Cerebroside, a type of sphingolipid, most commonly found inthe body?

Back 53

Myelin Sheath

Front 54

Where is Ganglioside, a type of sphingolipid, most commonly found inthe body?

Back 54

Myelin Sheath

Front 55

The lipids in this group contain a characteristic fused ring system with a hydroxyl or keto group on carbon 3 (the lower leftmost carbon).

Back 55

Steroids

Front 56

What is the most abundant steroid in mammalian tissue?

Back 56

Cholesterol (note: it's a steroid, but NOT a steroid hormone)

Front 57

This steroid is an important component of cellular membranes, modulates membrane fluidity

Back 57

Cholesterol

Front 58

This steroid is a precursor for the synthesis of steroid hormones, skin-derived vitamin D, and bile acids

Back 58

Cholesterol

Front 59

How are major steroid classes distinguished from each other?

Back 59

By the total number of carbons, and other minor variations

Front 60

How many carbons in:
1. Cholesterol?
2. Bile acids?
3. Progesterone and Adrenocortical Steroids?
4. Androgens?
5. Estrogens?

Back 60

1. 27 carbons
2. 24 carbons
3. 21 carbons
4. 19 carbons
5. 18 carbons (derived from aromatization of androgens)

Front 61

This group of lipids function as short-range, short-term signaling molecules.

Back 61

Eicosanoids

Front 62

Eicosanoids are generated from what common fatty acid?

Back 62

Arachidonic acid, a 20-carbon polyunsaturated omega-6 fatty acid that is released from membrane phospholipids by phospholipase A2

Front 63

Two pathways generate three groups of eicosanoids from arachidonic acid.

Prostaglandins (PGs) are formed by the action of _____ (an enzyme) on arachidonic acid

Back 63

Cyclooxygenase

Front 64

Two pathways generate three groups of eicosanoids from arachidonic acid.

Prostaglandin H2 (PGH2), the first stable prostaglandin produced from the cyclooxygenase pathway, is the precursor of other prostaglandins ____, _____, & _____, and for another, non-prostagandin _______

Back 64

1. PG E2, PG F2alpha, PG I2 (E, F-alpha, I)
2. Thromboxane (TXA2)

Note: all the "2s" should be subscripts

Front 65

Two pathways generate three groups of eicosanoids from arachidonic acid.

Prostaglandins, in general, do what, in terms of 1. inflammation, 2. Smooth muscle contraction, 3. Vascular tone?

Back 65

1. Promote acute inflammation
2. Stimulate or inhibit smooth muscle contraction, depending on type and tissue
3. Promote vasodilation (afferent arterioles) or vasoconstriction (cerebral vessels), depending on type and tissue

Front 66

Two pathways generate three groups of eicosanoids from arachidonic acid.

Thromboxane A2 (TXA2) is produced in _____ by the action of the enzyme _____ on Prostaglandin H2 (PGH2)

Back 66

1. Platelets
2. Thromboxane Synthase

Front 67

Thromboxane A2 (TXA2) strongly promotes arteriole _____ (contraction or dilation?) and platelet (inhibition or aggregation?)

Back 67

1. arteriole contraction
2. platelet aggregation

Front 68

What drug inhibits the enzyme thromboxane synthase, thus reducing Thromboxane A2 levels?

Back 68

Dipyramidole

Front 69

What kinds of drugs acetylate and inhibit cyclooxygenase?

What does this do to the levels of prostaglandins and thromboxane?

Back 69

1. Non-steroidal anti-inflammatory drugs (NSAIDS) like aspirin

2. Reduces the levels of prostaglandins (anti-inflammatory effect) and reduces the level of thromboxane (anti-thrombotic effect due to reduced platelet aggregation, which explains the benefit of aspirin for cardiovascular disease)

Front 70

Two pathways generate three groups of eicosanoids from arachidonic acid.

Leukotrienes are ____ (cyclic or non-cyclic?) compounds whose synthesis begins with the hydroxylation of arachidonic acid by the enzyme _______

Back 70

1. non-cyclic (unlike prostaglandins?)

2. Lipooxygenase (as opposed to cyclooxygenase for the PG pathway)

Front 71

Which Leukotriene is both:
1. a strong chemotactic agent for neutrophils and
2. promotes neutrophil adhesion to endothelial cells?

Back 71

LTB4 (B, not C, D, or E)

Front 72

Which Leukotrienes are involved in allergic reactions (e.g. Bronchoconstriction)?

Back 72

LTC4, LTD4, LTE4 (this is because they are contained in the Slow-reacting substance of anaphylaxis SRS-A)

Front 73

Which Leukotrienes are involved in increased vasoconstriction, and increased vascular permeability

Back 73

LTC4, LTD4, LTE4 (they are also involved in bronchoconstriction)

Front 74

Two pathways generate three groups of eicosanoids from arachidonic acid.

This antileukotriene drug inhibits lipooxygenase. What is it called?

Back 74

Zileuton

Front 75

Two pathways generate three groups of eicosanoids from arachidonic acid.

These 2 antileukotriene drugs block leukotriene receptors on target cells. What are they called?

Back 75

Zafir-lukast, and monte-lukast (both end in "-lukast")

Front 76

What class of drugs are used in the treatment of asthma?

Back 76

Antileukotrienes (Zileuton, zafirlukast, montelukast) because they inhibit these potent bronchoconstrictors LTC4, LTD4, LTE4