Biochem Final Exam - Lipids

Front 1

What are the four general classes of lipids?

Back 1

triaglycerol, phospholipid, steroid, glycolipid

Front 2

Steroids are derived from what molecule?

Back 2

cholesterol

Front 3

Where are bile salts and acids made and where are they stored?

Back 3

They are made in the liver and stored in the gallbladder.

Front 4

What is the function of bile salts and acids? What is the difference?

Back 4

Derivatives of cholesterol that aid in the emulsification of dietary lipids. Bile acids + amino group are bile salts.

Front 5

What lipid molecule is the precursor for bile acid formation?

Back 5

Cholesterol

Front 6

What are the functional roles for CCK and secretin in lipid digestion?

Back 6

Cholecystoknin (CCK) triggers the gallbladder to release bile, activates the pancreas to secrete digestive enzymes and slows down the movement of gastric contents to the small intestine.

Secretin stimulates the liver and pancreas to release bicarbonate in order to neutralize intestinal contents and stabilize the pH for digestion.

Front 7

What are the common causes of steatorrhea?

Back 7

Fat in stool due to poor digestion (lack of bile or deficiency in bile or pancreatic enzyme formation) or poor absorption (defective intestinal mucosa or shortened bowel).

Front 8

What is Celiac Disease?

Back 8

An autoimmune disorder in small intestine that results from damage to the lining of intestines due to gluten presence. Results in chronic inflammation and makes it hard for the body to absorb nutrients especially, Ca2+, fat, iron and folate.

Front 9

Which vitamins are deficient in lipid malabsorption syndromes?

Back 9

A, D, E, K

Front 10

Which vitamin deficiency alters Prothrombin Time?

Back 10

Vitamin K helps with blood clotting so a deficiency can prolongs PT time.

Front 11

Which vitamin alters Ca2+ and bone formation processes?

Back 11

Vitamin D.

Front 12

What fats are in milk?

Back 12

Butyric and capric acid, fatty acids with 4-10 carbon chain lengths

Front 13

Name two common saturated fats in lipid membranes.

Back 13

palmitic acid and stearic acid

Front 14

Name two common monosaturated fats.

Back 14

palmitoleic acid and oleic acid

Front 15

What are the two essential fatty acids? Which is the omega-3 fatty acid?

Back 15

linoleic acid and alpha-linolenic acid (the precursor for omega-3 fatty acid)

Front 16

Which fat is the precursor the prostoglandins?

Back 16

arachidonic acid

Front 17

What are the symptoms of essential fatty acid deficiency?

Back 17

scaly dermatitis (ichthyosis) and visual and neurologic abnormalities

Front 18

What is a glycerolphospholipid?

Back 18

Phospholipds that contain glycerol

Front 19

What is a cardiolipin? Where is it found?

Back 19

Diphosphatidylglycerol.

Found in inner mitochondrial membrane.

Front 20

How does the platelet-activating factor differ from glycerolphospholipids?

Back 20

PAF has an ether linkage and connects to signal molecules.

Front 21

What is the abbreviation for dipalmitoylphosphatidyl choline?

Back 21

DPPC

Front 22

What is the role for DPPC?

Back 22

Determines if fetal lungs are mature

Front 23

What is RDS?

Back 23

Respiratory Distress Syndrome, insufficient surfactant production and/or secretion, sometimes seen in preterm infants, or adults after an infection or trauma.

Front 24

What does PG (prostaglandin) stand for? Functions?

Back 24

Vasoconstriction and vasodilation, inhibits or promotes platelet aggregation stimulates uterine contraction.

Front 25

What does TX (thromboxane) stand for? Functions?

Back 25

promotes platelet aggregation, vasoconstriction, mobilizes intracellular calcium, contraction of smooth muscle

Front 26

What does LT (leukotriene) stand for? Functions?

Back 26

inflammation and inflammatory processes as well as fight infection

Front 27

Arachidonic acid is the precusor for both 5-lipoxygenase and COX. Which pathway is enhanced in the pathophysiology of asthma?

Back 27

5-lipoxygenase

Front 28

What is COX?

Back 28

fatty acid cyclooxygenase, an isoenzyme

Front 29

What compounds inhibit COX-1 and 2?

Back 29

aspirin, indomethacin and phenylbutazone (all NSAIDs)

Front 30

What is the importance for a selective COX Inhibitor?

Back 30

it is important to know b/c Cox-1 inhibitors cause stomach and kidney problems as well as impaired clotting. Cox-2 is associated with increased risk of heart attacks.

Front 31

What processes promote COX2 products?

Back 31

cytokines, endotoxin, growth factors, tumor promotors

Front 32

In the production of inflammatory lipid modulators, where do corticosteroids inhibit?

Back 32

Inhibit phospholipids --> arachadonic acid

Front 33

What is prednisone?

Back 33

Prednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug.

Front 34

What is the precursor for bile acids, steroid hormones and vitamin D?

Back 34

cholesterol

Front 35

Explain the pathophysiology of cholelithiasis (pg226).

Back 35

decrease in bile acids that cause cholesterol to precipitate in the gallbladder leading to gall stones.

Front 36

Arrange the common plasma lipoprotein particles on the basis of size and density.

Back 36

From smallest size/highest density to largest size/lowest density: HDL, LDL, VLDL, chylomicron.

Front 37

What are the function of apolipoproteins?

Back 37

bind to lipids and tell them where to go and allows enzymes to be coactivators.

Front 38

In general terms, provide and overview of the metabolism of chylomicrons and VLDL.

Back 38

1. Chylomicrons, TAG rich, are assembled in the intestinal mucosal cells.
2. Apo C II and E are added by HDL.
3. lipoprotein lipase activated by APO C II and E degrades chylomicrons
4. Apo C II and E added back to HDL.
5. Chylomicron remnants endocytosed by liver

Front 39

What is the difference between APO B-48 and APO B-100?

Back 39

APO B-48 is exclusive to chylomicrons and synthesized on rough ER.

APO B-100 is synthesized in the liver and found in VLDL and LDL.

Front 40

What is the role for HDL, the good cholesterol?

Back 40

HDL is responsible for reverse cholesterol transport and transfers apolipoproteins.

Front 41

What reaction is catyalyzed b lipoprotein lipase and how is it activated?

Back 41

It is activated by APO C-II and it hydrolyzes triacylglycerol contained in chylomicrons into free fatty acids and glycerol.

Front 42

What is the role of oxidized liproteins in plaque formation?

Back 42

LDL gets oxidized by ROS when too much LDL present. Macrophages pick up oxLDL in blood and together they become foam cells. Foam cells release cytokeines that cause proliferation of vascular damage and atherosclerosis.

Front 43

What are scavenger receptors?

Back 43

take up oxLDL

Front 44

What is a foam cell?

Back 44

Macrophages with oxLDL attached.

Front 45

What are cytokines?

Back 45

Signal inflammatory response

Front 46

How does this process affect hemostasis?

Back 46

causes blood clots

Front 47

Which steroid is the common precursor for glucocorticoids, mineralcorticoids and sex hormones?

Back 47

Progesterone

Front 48

Which organs synthesize and secrete which hormones?

Back 48

Adrenal cortex secretes cortisol, aldosterone and androgens.
Ovaries and placenta secrete estrogen and progestins.
Testes secrete testosterone. (Pg 237)

Front 49

What is the role for transcortin?

Back 49

binds cortisol, progestins and glucocorticoids.

Front 50

What is the role for sex hormone binding globulin (SHBG)?

Back 50

binds androgens and estrogens.

Front 51

What enzyme system catalyzes hormone synthesis?

Back 51

desmolase

Front 52

What is CAH?

Back 52

Congenital Adrenal Hyperplasia

Front 53

When one path is blocked, for example with 21 alpha-hydroxylase deficiency (the most common CAH), what is the phenotype?

Back 53

Results in an overproduction of androgens leads to masculization of external genitalia in females and early virilization in males.

Front 54

What is the role for aromatase inhibitors?

Back 54

Used in the treatment of estrogen-responsive breast cancer in post-menopausal women.

Front 55

What is the role for releasing factors?

Back 55

release hormones for hypothalamus to anterior lobe of pituitary

Front 56

Which pituitary hormones affect which steroid hormone synthesis?

Back 56

Luteinizing hormone stimulates testosterone and estrogen/progesterone synthesis.

Follicle-stimulating hormone stimulates estrogen in females and androgens in males.

ACTH stimulates secretion of glucocorticoids.

Front 57

What is the function of cortisol?

Back 57

Increases gluconeogenesis, produces anti-inflammatory action and aids in protein breakdown in muscle.

Front 58

Function of aldosterone?

Back 58

Stimulate renal reabsorption of Na+ and excretion of K+.

Front 59

Function of estrogens?

Back 59

Controls menstrual cycle, promotes development of female secondary sex characteristics.

Front 60

Function of progesterone?

Back 60

Secretory phase of uterus and mammary glands and implantation of fertilized ovum.

Front 61

Function of testosterone?

Back 61

Stimulates spermatogenesis, promotes development of male secondary sex characteristics, promotes anabolism and masculinization of the fetus.

Front 62

What is the mechanism of steroid hormone action?

Back 62

binding of a steroid hormone complex to the HRE of the enhancer region and it activates the gene promoter causing transcription.

Front 63

What is HRE?

Back 63

Hormone response element

Front 64

In general terms, provide and overview of the metabolism of VLDL.

Back 64

1. TAG rich VLDL secreted by liver
2. Apo C II and E added to VLDL by HDL
3. VLDL degraded by lipoprotein lipase.
4. Apo C II and E returned to HDL.
5. LDL degraded by liver and tissues.