Wid1 - Biochemistry-Lipid Biochemistry And Metabolism

Front 1

Lipids are a _______-- diverse group of __________ compounds.

Back 1

chemically, bioorganic

Front 2

What is the common and defining feature of lipids?

Back 2

their insolubility in water.

Front 3

What to lipids tend to be soluble in?

Back 3

certain nonpolar solvents such as: chloroform, benzene, ether and petroleum ether.

Front 4

What are some examples of nonpolar solvents?

Back 4

chloroform, benzene, ether and petroleum ether.

Front 5

Name some compounds that are commonly referred to as lipids:

Back 5

oils, fats, fatty acids, triglycerides, phospholipids, sphingolipids, waxes and steroids (including cholesterol)

Front 6

What are the 4 Fat-soluble vitamins?

Back 6

KADE, they are also classified as lipids! based on their solubility

Front 7

What is the important function of of fats and oils?

Back 7

the prinicipal stored form of energy

Front 8

What is the impt. function of phospholipids and sterols?

Back 8

major STRUCTURAL elements of biological membranes.

Front 9

What is the function of wax?

Back 9

water repellent

Front 10

T/F Lipids can function as enzyme co-factors.

Back 10

True

Front 11

When is a lipids used as an electron carrier?

Back 11

Beta-oxidation

Front 12

What lipids function as light-absorbing pigments?

Back 12

vitamin A/retinol

Front 13

What is the function of lipid-rafts (signal transduction)?

Back 13

hydrophobic anchors

Front 14

What lipid within the body is an emulsifying agent?

Back 14

bile acids in the gall bladder

Front 15

What are some hormones that are considered as lipids?

Back 15

testosterone and cortisol (start as cholesterol-steroid)

Front 16

What type of lipid functions in cell surface recognition?

Back 16

sphingolipids

Front 17

What is the function of the phosphatidylinositol, and prostaglandins. (lipids)

Back 17

INTRA cellular messengers.

Front 18

Fatty acids are ___________ chains often with _______- number carbon atoms ranging from _____ to ___ and a terminal carboxylic ______ (often referred to as the head).

Back 18

hydrophobic, even, 4-36, acid

Front 19

Next to the "head" carbons are named from _____- to the end carbon ____.

Back 19

alpha -beta - omega

Front 20

T/F the hydrocarbon chain may be saturated or unsaturated.

Back 20

True

Front 21

When a fatty acid is saturated what does this mean?

Back 21

it contains NO dble bonds

Front 22

When a fatty acid is unsat. what does this mean?

Back 22

contains one or more double bonds, the carbon chain in double bonds is not saturated with hydrogen atoms; less than the maximum number of hydrogen atoms possible are bond to the carbon chain.

Front 23

What two configuration can a double bond be in?

Back 23

cis or trans

Front 24

t/f all three types of fatty acids are found in living systems.

Back 24

true

Front 25

What fats are more saturated? animal or vegetable

Back 25

animal

Front 26

t/f fatty acids are always in the cis configuration

Back 26

true

Front 27

Describe the cause of respiratory distress syndrome as related to lipids.

Back 27

RDS occurs in preterm infants and is a major cause of infant mortality and morbidity. It results from a lack of the lipid DIPALMITOYL PHOSPHATIDYL CHOLINE, a major component of the lung surfactant that keeps alveoli open by reducing the surface tension of the alveolar walls.

Front 28

In general describe the components of plasmalogens.

Back 28

Components of the plasmalogens: these are phospholipids that have an alpha,beta-unsaturated ether linkage at carbon 1 of the glycerol backbone. The ethanolamine form predominates but serine and choline are also found. They comprise much of the lipid in mitochondria. The last step in their synthesis is the action fo a desaturase requiring NADPH and oxygen to introduce the double bond.

Front 29

Differentiate the structures of the three ether phospholipids listed.

Back 29

Each contains a choline at the 3rd carbon and has a glycerol backbone. Each carbon #1 has a ether linkage.
In phosphatidal ethanolamine there is a double bond neighboring the ether linkage at carbon 1.
In an ether phospholipid there the oxygen is linked to an arbitrary R group.
In platelet-activation factor the 'special' factor is that at carbon 2 there is an acetyl group attached.

Front 30

In general describe the components of platelet-aggregation factor.

Back 30

This is an ether phospholipid in which an acetyl group has been introduced at position 2 during synthesis. As a result it is more WATER SOLUBLE. It acts in very small amounts and causes platelet aggregation as well as many other effects such as increasing airway and pulmonary edema in the lungs and mediating hypersensitivity and inflammatory reactions.

Front 31

phosphotidal ethanolamine is related to what type of tissue?

Back 31

nerve tissue

Front 32

phosphotidal choline is related to what type of muscle?

Back 32

heart muscle

Front 33

An ____________ ____________ has a saturated ether linkage at C1 and a normal acyl linkage at C2. When it has an unsaturated linkage at C1 it is a __________. When it has an acetyl group instead of a acyl linkage at C2 it is a _______.

Back 33

ether phospholipid, plasmalogen, platelet-activating factor

Front 34

What are the components of a sphingomyelin?

Back 34

has a backbone: spingospine
has a fatty acyl group (LCFA) bound to the amine
and a choline.

Front 35

________ is a component of the myelin sheath that surrounds nerves.

Back 35

sphingomyelin

Front 36

What are the components of cerebrosides?

Back 36

spingosine backbone
Fatty acyl group
One sugar - glucose or galactose group bound to C1

Front 37

What are the components of gangliosides?

Back 37

a spingospind back bone with a fatty acyl group: ceramide
ceramide is bound to a Glc-Gal-GalNAc. Also bound to The Gal after Glc is NANA (N-Acetyneuramic acid or sialic acids)
bascially the same thing as cerebroside with added sialic acids and other sugars.

Front 38

_________ is a spingosine + a fatty acyl group

Back 38

ceramide

Front 39

If you addd CDP-choline to ceramide what do you get?

Back 39

Sphingomyelin

Front 40

If you add UDP-glucose or galactose what do you get?

Back 40

A cerebroside

Front 41

What is a sulfatide composed of? and what category of lipids is it in?

Back 41

sulfatide is a sphingolipid.
Structure: ceramide - Gal-3-SO3 (sulfate group)

Front 42

If a spingholipid has 1 sugar it is a _______. if it has less than one sugar it is a __________.

Back 42

1 sugar: cerebroside
> 1 sugar: globoside

Front 43

_______________- are involved in intercellular communication adn antigenic determinant (eg: ABO blood groups).

Back 43

Sphingolipids

Front 44

The sphingolipids are a group of complex lipids containing the base _________-.

Back 44

sphingosine

Front 45

What is the initial precursor to a sphingospine?

Back 45

Serine + Palmitoyl CoA = releases CO2...(reduced) NADPH->NADP...(oxidized) FAD -> FADH2

Front 46

Where is the amide linkage found in a ceramide?

Back 46

off of C2 between the nitrogen and fatty acyl group

Front 47

If a Fatty acid is removed from ceramide what is now produced?

Back 47

sphingosine

Front 48

T/F Spingosine is also known as a amine alcohol.

Back 48

True

Front 49

All of these disease are of what type?
Gaucher's Disease
Tay Sach's Disease
Fabry's Disease
Krabbe's Disease
Nieman-Pick disease
Metachromatic leukodystrophy

Back 49

Sphingolipidoses
"Fabry met a grouchy (Gaucher) man at sach's fifth ave. (Tay Sach's), a crabby (Krabbe's) man at Niemann-Marcus (Niemann-Pick disease) and ended up buying a metachromatic (metachromatic leucodystrophy) suit. - Mainly remember those and recognize the rest.

Front 50

The __________ (or more specifically ________________ since they involve the catabolism of sphingolipids) are genetic disease in which a missing enzyme results in the accumulation of lipid intermediates in the lysosomes.

Back 50

lipidoses or sphingolipidoses

Front 51

List the name of the ketone bodies..

Back 51

acetoacetate, beta-hydroxybutyrate and acetone

Front 52

How is acetoacetate formed?

Back 52

A direct route resulting in the condensation of 2 molecules of acetyl CoA followed by deacylation.
2 acetyl CoA -> acetoacetyl CoA + CoA
acetoacetyl CoA - > acetoacetate + CoA

Front 53

Liver mitochondria have the capacity to convert some of the acetyl CoA produced from glycolysis or fatty acid oxidation into what hve been called the ________ _________.

Back 53

ketone bodies

Front 54

How is beta-hydroxybutyrate formed?

Back 54

the acetoacetate produced is partially converted to beta-hydroxybutyrate - indirectly.

Front 55

What is the indirect rout of ketone body synthesis?

Back 55

The indirect rout involves the prior formation of beta-hydroxy -beta methylglutaryl-CoA, the key intermediate in the syntesis of sterols and also an intermediate in leucine catabolism.
Rxn: acetoacetyl CoA + acetyl CoA -> beta-hydroxy-beta methylglutary-CoA + CoA
beta-hydroxy-beta-methylglutaryl-CoA -> acetoacetate + acetyl CoA
The sum of these two rxns =
acetoacetylo CoA -> acetoacetate + CoA

Front 56

How would an individual get ketosis or ketoacidosis?

Back 56

Normally the acetoacetate produced is partially converted to beta-hydroxybutyrate and together these ketone bodies are metabolized by oxidation in peripheral tissues. in some disease state such as diabetes the levels can be elevated and the condition known as ketosis arises.

Front 57

What is the 'use' for the production of ketone bodies?

Back 57

used for transport - Cori cycle in the Liver

Front 58

What compounds are involved in cholesterol synthesis?

Back 58

The entire cholesterol molecule is made up of acetate units. Beta-hydroxy-beta-methylglutaryl CoA reduction to mevalonate mediated by reduced NADP is the main control step, i.e. high levels of cholesterol inhibit this step. Newer cholesterol-lowering drugs such as Mevacore (lovastatin) inhibit the reductase enzyme and therfor cholesterol synthesis. Remember that HMG-CoA is also involved in the production of the ketone bodies. Once mevalonate is decarboxylatd to form two C5 compounds (isopenenyl pyrophosphate and 3,3,-dimethylallyl pyrophosphate) a series of condensations takes place.
2 C5 units -> 1 C10 unit (geranyl pyrophosphate
C10 + C5 -> 1 C15 unit (farnesyl pyrophosphate)
2 C15 units -> 1 C30 unit (squalene), an NADPH-mediated reduction
Squalene cyclizes to form lanosterol, which ultimately becomes choloesterol, the precursor to all the other steroids and bile salts.

Front 59

Given a structure of cholesterol derivative, identify it as a sterol, steroid, vitamin, or bile acid/salt.

Back 59

Sterol: are a subgroup of steroids that have 8-10 carbon side chain at C17 and a -OH group at C3. 5 closed rings
Steroids: dervied from sterols - usually have a double bonded oxygen (except estradiol) and have all 4 rings connected.
Vitamins: have a beta bound alcohol and rings are open (some of them).
Bile Salts: 4 rings are closed but have alpha bound alcohol

Front 60

What is the precursor of other sterols and other related steroids, which form a large group of compounds with varied metabolic roles from structural to hormonal?

Back 60

Cholesterol

Front 61

T/F The requirement for NADPH explains the need for an active pentose pathway in sterol synthesizing tissues.

Back 61

True

Front 62

The ________ _______ taurocholic acid and glycocholic acid are the conjugation products of cholic acid ( a bile acid) with the amino acids taurine and glycien.

Back 62

bile salts

Front 63

The bil acids are made from __________, conjugated and stored inbthe __- _______ for release into the intestinal lumen.

Back 63

cholesterol, gall bladder

Front 64

What are the two main function of bile salt/acid?

Back 64

1. act as an emulsifier to enhance digestion and absorption of lipids.
2. a means of excretion of cholesterol

Front 65

__________ is when levels of keton bodies gets too high and lowers pH of blood. Can actually smell it on someones breath when acetone levels are too high (diabetes).

Back 65

ketoacidosis

Front 66

The pneumonic " London Has Many Incest Girl Friends Sucking Candy" relates to what?

Back 66

London: Leucine
Has: HMG-CoA
Many: Mevalonate
Incest: Isopentenyl pyrophosphate (C5)
Girl: Geranyl pyrophosphate (C10)
Friends: Farnesyl pryophosphate (C15)
Sucking: Squalene (C30)
Candy: Cholesterol (C27)

Front 67

What does Insulin and Glucagon cause in cholesterol synthesis?

Back 67

Glucagon: DEC. cholesterol synthesis - break down
Insulin: (storage) INC cholesterol synthesis

Front 68

What is the rate limiting step of the production of bile acids?

Back 68

7-alpha-hydroxylase, which is limited by a lack of vitamin C.

Front 69

About ____ % of the bile acids are returned to circulation by reabsorption, mostly in the ileum. This is known as ____________ __________.

Back 69

98-99%, enterohepatic circulation

Front 70

Describe how the 5 classes of lipoproteins are determined and the relationship of these classes to the lipoproteins composition.

Back 70

Lipoproteins are classified by density and accordingly increasing content of protein and decreasing amount of lipid.

Front 71

What lipoproteins are associated with Apo A-1? what is the characteristics/function of these apolipoproteins?

Back 71

HDL, chylomicrons. Activates LCAT (lecithin-cholesterol acyl transferase), ligand for HDL receptor

Front 72

What lipoproteins is associated with apoprotein Apo B-100? and what is the characteristics/function of these apolipoproteins?

Back 72

LDL, VLDL, IDL. It is synthesized in the liver, Ligand for LDL receptor, mediated tissue uptake of LDL.

Front 73

What lipoproteins is associated with apoprotein Apo B-48? and what is the characteristics/function of these apolipoproteins?

Back 73

Chylomicrons and its remnants. Synthesized in the intestine. 48% of B100 size.

Front 74

What lipoproteins is associated with apoprotein Apo C-II? and what is the characteristics/function of these apolipoproteins?

Back 74

VLDL, HDL, chylomicrons. readily transferred among the classes; activator of LIPOPROTEIN LIPASE.

Front 75

What lipoproteins is associated with apoprotein Apo E? and what is the characteristics/function of these apolipoproteins?

Back 75

VLDL, HDL chylomicrons and it's remnants. High in some types of hyperlipoproteinemia. Ligad for chylomicron remnant receptor in liver and LDL receptor

Front 76

The metabolism of the plasma lipoprotiens is complex, and is extremely important because of the relationship to ________ levels and atherosclerosis.

Back 76

cholesterol

Front 77

What two apoproteins are important in regulating enzymes of lipoprotein metabolism, including lipoprotein lipase and LCAT?

Back 77

apo A-1: activates LCAT
Apo C-II: activates lipoprotein lipase.

Front 78

Describe the the relationship of the five classes of lipoproteins to the lipoprotein's composition.

Back 78

when they increase in density, accordingly increase in protein content and decrease in lipid.

Front 79

What is the order of increasing density of the lipoproteins/

Back 79

Chylomicron (smallest) -> VLDL - > IDL - > LDL -> HDL

Front 80

T/F the lipoproteins exist as preformed (or nascent) structures and some are referred to as "remnants" after losing some lipid tissues.

Back 80

true

Front 81

What is the role of chylomicrons, in the transport of lipids in the bloodstream from one tissue to another as described in the text material and accompanying the diagrams (pg. 19-20 of the handout).

Back 81

Chylomicrosn are the largest lipoprotein particles and contain the highest percentage of lipids, primarily TAGs. They come from the absorption of dietary lipid in the intestine and carry lipids int h blood stream to other tissues. They go from a nascent form to full chylomicrons by obtaintin additional apo C-II and apo E from HDL. TAG ishydrolyzed by the enzyme lipoprotein lipase to fatty acids, which are available to tissue for re-synthesis into storage fat. The removal of 80-90% of TAG and transfer of apo A and apoC C to HDL converts chylomicrons to smaller particles, known as chylomicron remnants. In the liver, remnants bind to receptors, including the LDL receptor, via Apo E are endocytosed, and the lipid and protein components hydrolyzed.

Front 82

What lipoprotein has the highest content of cholesterol and cholesterol ester?

Back 82

LDL

Front 83

What is the role of VLDL, in the transport of lipids in the bloodstream from one tissue to another as described in the text material and accompanying the diagrams (pg. 19-20 of the handout)

Back 83

transport lipid from the liver to peripheral tissues such as muscle and adipose tissue, where they are also broken down by lipoprotein lipase and the fatty acids are taken up by these peripheral cells the VLDL remnants (IDL) are removed from the circulation by hepatocytes or lose further lipid to become LDL.

Front 84

What process is intimately involved with processes leading to atherosclerosis?

Back 84

the transport of lipids in the body

Front 85

What apoprotein does the liver recognize and endocytose?

Back 85

Apo E

Front 86

Why is LDL considered bad and HDL considered good?

Back 86

LDL: because it delivers cholesterol to perip. tissues.
HDL: takes cholesterol away from peripheral tissues.

Front 87

What is the role of LDL in the transport of lipids in the bloodstream from one tissue to another as described in the text material and accompanying the diagrams (pg. 19-20 of the handout)

Back 87

The low density lipoproteins mostley result fromthe removal of triglyceride from the VLDL. The resultant LDLs are high in cholesterol and cholesterol ester, and carry them to peripheral tissue other than the liver.

Front 88

What is the role of HDL in the transport of lipids in the bloodstream from one tissue to another as described in the text material and accompanying the diagrams (pg. 19-20 of the handout)

Back 88

HDL has the least amount of lipid and play a key role in the REVERSED TRANSPORT of cholesterol from extrahepatic tissues to the liver. They are syntehsized in the liver and gut, contain Apo-A, but only liver can furnish the apo C and E. Nascent HDL is small and disk-like particles that are phopholipids-rich. HDL travel from the liver to peripheral tissues where they pick up cholesterol and return it to the liver for processing. They also furnish apo C-II and apo E to chylomicrons and VLDL and exchange cholesterol esters with VLDL and triglyceride. HDL contain the enzyme LCAT, which converts cholestrol to cholesterol esters by the addition of fatty acids to the 3-position.

Front 89

_________ and HDL always trade triglycerides for cholesterol esters.

Back 89

VLDL

Front 90

T/F Cholesterol sits on outside of lipid bilayer of lipoprotein and cholesterol ester gets internalized becuase it is hydrophobic

Back 90

true

Front 91

What is the role of LCAT in the transport of cholesterol from peripheral tissues to the liver?

Back 91

HDL contains the enzyme LCAT, which converts cholesterol to cholesterol esters by the addition of fatty acids to the 3 position.

Front 92

Discuss the central role of the liver in lipid transport and metabolism.

Back 92

The liver is where lipogenesis mainly occurs. Also it is the place of reuptake and breaks down the 'used' lipoproteins

Front 93

Explain how choline deficiency, essential fatty acid deficiency, carbon tetrachloried and puromycin might cause fatty liver and interfere with the liver's role.

Back 93

All of the agents listed inhibit protein synthesis, and hence their presency causes lipid accumulation in the liver. They may also cause fatty liver by other mechanisms. For example, carbon tetrachlordie is a free radical generator that cuases disruption of membrnase such as those of the ER (where phopholipids are synthesized). Carbon tetrachlordie is rapid acting and appartenly affects secretion as well as synthesis. Some protection againt the lipid peroxidation due to arbon tetrachloride is obtained by vitamin E supplemented diets. Alcholism also leads to fatty liver by increasing hepatic TAG synthesis, decreasing fatty acid oxidation, and decreasing TCA cycle probably due to an accumulation of NADH.

Front 94

Describe where the various lipases and phospholipases cleave their substrates and the products that are formed.

Back 94

The phospholipases are designated A1, A2, C or D depending on the point of hydrolysis. The phospholipases A1 and A2 remove a fatty acids from teh C1 (mostly saturated ) or C2 position, respectively. Phospholipase C removes the alcohol phosphate (phosphocholine), leaving a diglyceride, while phopholipase D remove only the alcohol (choline), leaving a phosphatidic acid.
Gastric lipase: is active in the stomach to hydrolyze a short and medium chain fatty acids, or a long chain unsaturated fatty acid from the 1 or 3 position of a triglyceride to form a 1,2-diacylglyceride.
Pancreatic lipase is acting almost exclusively on the 1 or 3 positioncontinues the digestion of fatty acylglyceride to 2 monoglycerides, which form micelles that can be absorbed into the intestinal epithelial cells.

Front 95

What is the function of colipase?

Back 95

is a protein required for the function of phospholipase A2

Front 96

T/F Lingual lipas has limited digestion effect.

Back 96

true

Front 97

What 4 components does pancreatic juice have the emulsifies lipids?

Back 97

Pancreatic lipase, phospholipase A2, Colipase, Trypsin

Front 98

What is the function of trypsin?

Back 98

is the proteolytic enzympe needed to activate both phospholipase A2 and colipase.

Front 99

Where does phospholipase A2 act?

Back 99

it is a calcium dependent enzyme, acting on the 2 position of phospholipids.

Front 100

Discuss the process of digestion leading to formation and absorption of chylomicrons.

Back 100

Most lipids are not broken down in the mouth, but are mixed with carbohydrates and protein to form chyme in the stomach. This ix is slowly emptied into the duodenum where lipids stimulate CCK secretion. CCK causes secretion of pancreatic lipas and stimulates pancreatic secretion of bicarbonate and gall bladder's release of bile salts. Bile helps emulsify fats to increase surface areas for digestion, promoting the breakdown of Triglyceride by pancreatic lipase. In the intestinal cells, monoglycerides and fatty acids are recombined to form triglycerides and incorporated into chylomicrons for transport in the blood stream.

Front 101

Describe specifically intestinal reabsorption.

Back 101

In the intestinal walls 1 - monoglycerides are hydrolyzed to glycerol and fatty acid by an INTESTINAL LIPASE. Ultimately, triglycerides are formed through the pathway previously seen starting with glycerol phosphate. chylomicrons are formed, consisting of triacylglycerols, phospholipids, cholesteryl esters, cholesterols, and fat-soluble vitamins. These pass into the portal venous blood by way of the thoracic duct.

Front 102

_____________ are signaling molecules that exert complex control over many bodily systems, mainly in inflammation or immunity, and as messengers in the CNS and hence chronic diseases.

Back 102

eicosanoids

Front 103

eicosanoids are so-names because they are all derived from the 20-carbon unsaturated fatty acids (particularly __________).

Back 103

arachidonate

Front 104

The ____________ (LT) and lipoxins, formed from arachidonate principally by the enzyme lipoxygenase.

Back 104

leukotrienes

Front 105

The __________, formed from arachidonate through the enzyme cyclooxygenase.

Back 105

prostanoids

Front 106

What enzyme causes ring formation?

Back 106

cyclooxygenase

Front 107

What is further classified as prostaglandins (PG), thromboxanes (TX) and the prostacyclins (PGI)

Back 107

prostanoids

Front 108

What class are leukotrienes, lipoxins, prostanoids from?

Back 108

Eicosanoids.

Front 109

The synthesis of eicosanoids starts with the release of arachidonic acid from the phospholipids of the ____ __________ through the action of a ____________ A2.

Back 109

cell membrane, phospholipase A2

Front 110

The phospholipase A2 during eicosanoids synthesis hydrolyzes the ester linkage between a fatty acid and the hydroxyl at carbon _____ of the glycerol backbone, releasing the _____ _____.

Back 110

2, fatty acid

Front 111

What initiate the synthesis of eicosanoids?

Back 111

tissue injury and inflammation. special inflammatory cells, monocytes and neutrophils, invade the injured tissue and interact with the resident cell and this lead to arachidonate release and eicosanoid synthesis.

Front 112

T/F Arachidonate is converted into leukotrienes by the linear pathway.

Back 112

true

Front 113

T/F arachidonate is converted to prostaglandins by the cyclic pathway.

Back 113

true

Front 114

What is the first step in the synthesis of leukotrienes?

Back 114

it is catalyzed by 5-lipoxygenase from arachidonate to 5-HPETE -> leukotriene-A4-> which can then be converted to various other leukotrienes

Front 115

Leukotrienes are produced by _________ ______________ cells and have roles in inflammation an dasthmatic constriction of the bronchioles.

Back 115

immune system

Front 116

________ of 5-lipoxygenase are used in anti-asthma medication.s

Back 116

Inhibitors

Front 117

What is the MAJOR role of lipoxygenase?

Back 117

to convert arachindonate to 5-HPETE -> leukotriene for immune system response.

Front 118

What enzyme is responsible for introducing oxygen (2O molecules) into the arachidonic acid to convert it to PGG2? also forms rings...

Back 118

cyclooxygenase

Front 119

What follows the cyclooxygenase activity during prostaglandins synthesis?

Back 119

peroxidase action using reduced glutathione, the enzyme rapidly inactivates itself.

Front 120

What is the role of corticosteroids during eicosanoid synthesis?

Back 120

inhibits phospholipase A2

Front 121

The cyclooxygenase activity exists as two different isozymes designated ______- and ______ in most tissues.

Back 121

Cox-2 and Cox-2

Front 122

What is the product that is formed after cyclooxygenase and peroxidase?

Back 122

PGH2

Front 123

___________- primaryily have the effects of influencing platelet aggregation (inhibit or incr.) and constrict or relaxing blood vessels.

Back 123

prostaglandins.

Front 124

What prostaglandin is producd in platelets and functions to promote platelet aggregation?

Back 124

thromboxane - mostly known for neg. impact, particularly on cardiovascular health and also contributer to asthma - may play a role in immediate response to injury to limit blood loss.

Front 125

What prostaglandin is produced in blood vessel walls and an inhibitor of thromboxane action.

Back 125

prostacyclin

Front 126

What effect does aspirin have on eicosanoid synthesis?

Back 126

inhibits the biosynthesis of prostaglandins. Inhibiits COX-1 an COX-2 of cyclooxygenase.

Front 127

_______ ____________: is an atom or molecule possessing an unpaired electron. They are highly reactive, any may react with paired electrons to create a new free radical or with another free radical to become neutralized.

Back 127

Free radical

Front 128

_______: is an oxygen-containing compounds that reacts easily with other molecules, resutling in potentially damaging modifications.

Back 128

Reactive Oxygen Species (ROS)

Front 129

What are the 3 rxn's of the antioxidation enzymes? and what are the enzymes names?

Back 129

catalase: 2 H2O2 -> 2 H2O + O2
Superoxid dismutase (SOD): converts the highly reactive superoxide (O2-) radical to the less reactive H2O2.
Glutathione peroxidase: catalyzes the reduction of a variety of hydroperoxides (ROOH and H2o2) using GSH, therby protecting mammalian cells against oxidative damage (requires selenium).

Front 130

What is the function of a dismutase?

Back 130

simultaneous oxidation and reduction

Front 131

What are the 4 antioxidant compounds?

Back 131

beta-carotene (Vit. A)
Ascorbic acid (Vit.C)
alpha-tocopherol (Vit. E)
Selenium ( is incorporated into protien to make selenoproteins which are antioxidants)
Glutathione (GSH)

Front 132

T/F Lipid peroxidation is non-enzymatic

Back 132

true

Front 133

How can free radicals be harmful?

Back 133

peroxyl radical can oxidize a wide variety of biological substrates and induce extensive oxidative base damage of DNA, causing mutations in human cells, as well as induce DNA strand breaks by oxidative attack on the DNA backbone.

Front 134

T/F the bipartite genotoxicity that peroxyl radicals have may be mainly responsible for the carcinogenic effects resulting from the membrane lipid peroxidation.

Back 134

true

Front 135

What is the role of Vit. E in Lipid Peroxidation?

Back 135

It is the antioxidant that neutralizes the free radical formed in this process. (note that GSH and Vit. C) can recieve the free radicals from vit. E