Exam1_L4_Carbs_Lipids Flashcards Preview

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Flashcards in Exam1_L4_Carbs_Lipids Deck (41)
1

Enantiomers-

Mirror images- same chemical characteristics (sweetness)
NATURE ONLY D SUGARS
NATURE ONLY L (AMINO ACIDS)

2

UDP-glucose C4 epimerase

galactose can be made from glucose using this epimerase. (glucose/galactose are c4 epimers)

3

Mutarotation

spontaneous, no-enzyme, reversible action where straight sugars form rings.
99% of mono sugars exist in ring structure
(good b/c aldehyde/ketones are usually very reactive)

4

6 membered ring- 5 membered ring

Pyranose 6 membered ring
Furanose 5 membered ring

5

Alpha and Beta anomers. How do you find anomeric carbon?

Count from last non-ring carbon
Alpha Anomer- (OH groups on same side )(restricted)
Beta anomer (OH opposite sides) (less hindered)

6

Glycation

NON ENZYMATIC- reaction of ALDEHYDE or KETONE group in a sugar with AMINO group in proteins and makes a SCHIFF BASE --> oxidized to "AGES"
(advanced glycation end products)


7

Effects of Protein glycation?

-Decreased function
-Damages collagen in BV walls
-form AGE's (advanced glycation end products)

8

Why is Chronic Hyperglycemia a concern?

CHglyC-> AGE's> Major contributor to diabetic pathology.
-nephropathy
-Peripheral vascular/cardiovascular complications

9

How do you measure glycation of Hb? Why?

HbA1C test-
-Tests how adequate diabetic patient is regulating blood sugar

10

What is Glycosylation?

Adding Polysaccharide (>20) or Oligosaccharide (3-12 component sugars) to proteins, lipids, or other organic molecules in an ENZYMATIC REGULATED manner

-Process of making glycolipids and glycoproteins

11

Is it oxidation or reduction-
Acid to aldehyde? Alcohol to acid? Alcohol to aldehyde?
Acid to alcohol?, aldehyde to alcohol?, aldehyde to acid?

ALCOHOL ALDEHYDE ACID OX>
RED

12

Where is glucuronic acid from? Where is Iduronic acid form? What charge at physiological pH

Glucuronic acid is oxidized form of glucose
Iduronic acid is oxidized form of Galactose

13

Why is oxidation of sugars important physiologically?

Glucuronate is charged and added to hydrophobic molecules in the liver so that they can be more soluble and excretable from the body.

14

What are Amino and N-acetylated amino SUGARS?

Amino (N containing) Sugars reacts with lipids, proteins, or sugars OH group to make Glycosaminoglycans GAG's , Glycolipids, or GlycoProteins

15

REDUCED SUGARS
C2 Epimers
C4 Epimers

Sugar ALCOHOLS
- Galactitol > galactose> Iduronic acid
-Sorbitol > Glucose > Glucuronic acid
-Mannitol > Mannose > multiple compounds

C2 epimers (Glucose Mannose)
C4 epimers (Glucose Galactose)

16

GAG's

LINEAR
POLYMERS of repeating DISACCHARIDES (50-150 repeats)
NEGATIVE CHARGE Attracts Water

17

Glycosides

Enzymatic reaction when a sugar molecule is COVALENTLY bound to the functional group of another molecule (not sugar) and is O or N linked

18

Glycosidases

Enzymes specific for glycosidic bonds; ie: alpha glucose configurations can be broken down by humans alpha glycosidases but we aren't able to break down the Beta configuration of glucose (CELLULOSE) with it's b1,4 glycosidic bonds.

19

18:3delta9,12,15

18 carbon lipid w/ 3 double bonds at carbons 9,12,15. Starting with carbon 1 at COOH end.

20

Name a lipid with 12 carbons and double bonds at 4,3,2.

12:3delta4,3,2

21

Omega system naming

start from carbon opposite COOH as carbon 1. name OMEGA then number of carbons until you get to first double bond.

22

What are the two essential fatty acids? Why?

Y-linoleic (w-6), and a-linolenic acids (w-3). Because we can't make FA's with double bonds past the carbon 9 position.

23

What is the precursor for arachidonic acid C20:4? what is arachidonic acid a major precursor for?

Linoleic w-6.
Arachidonic acid is MAJOR for EICOSANOID SYNTHESIS

24

What precursor for FA's needed in growth and development?

Linolenic w3 for w3 FA's

25

disease caused by deficiency in a-hydroxylase

REFSUM Disease
accumulation of phytanic acid in the blood and tissues causing neuronal damage. Treatment is diet low in phytanic acid and it's precursors

26

Branched chain FA's go through ______ _______ because it's ___________ on the _______carbon.

Alpha oxidation because its methylated on the beta carbon (3rd carbon from cooh) . Alpha hydroxylase is used but causes rufsum disease if there is a deficiency or if phytanic acid is built up in blood and tissues.

27

what happens to FA when hydrogenated?

trans configuration - Straight chains
(nature is all cis configuration-).

28

Steroids-

derived from cholesterol (membrane lipid, amphipathic),
-animal origin

29

Cholesterol Esters

Polar group of cholesterol is esterified into a Fatty Acid
-NOT in membrane, but non-polar

30

Ceramide

One long chain FA attached to sphingosine

31

3 types of amphipathic membrane lipids

1. Glycerolphospholipids, (choline, serine, inositol)
2. Spingolipids (sphinomyleins, glycosphingolipids; cerebrosides/gangliosides )
3. Cholesterol (steroids)

32

Choline, Serine, Inositol are what ?

Glycerolphospholipids- Amphipathic membrane lipids.
Choline- PC
Serine-PS (phosphatidylserine)
Inositol- PI (phosphatidylinositol)

33

What are the non membrane lipids?

FA's, Steroids, TAGS, Cholesterol esters

34

Sphingolipids- How is its derivative formed?

-Localized in WHITE MATTER of CNS
- derivatives of Ceramide (formed by esterification of a FA w/ amino group of Sphingosine)
-functional group attached to terminal OH of ceramide determines function

35

Lysosomal storage diseases

hereditary defects of lysosomal enzymes that degrade sphingolipids cause sphingolipidoses ie; Tay-Sachs & Gaucher's disease.

36

Sphingomyelins

phosphorylcholine attached to ceramide
-membranes of nerve tissue & blood cells
-Signal transduction

37

Cerebrosides

One GALACTOSE or GLUCOSE unit joined in B-glycosidic linkage to ceramide
-found in MYELIN SHEATH

38

Gangliosides

Oligosaccharide w/ one Sialic acid (N-acetyl neuraminic acid) residue linked to ceramide
-found in MYELIN SHEATH

39

Steroids

Lipids w/ rigid flat ring system w. OH or Keto group on C3.
Cholesterol- most abundant steroid in tissue- membrane fluidity- precursor of hormones (VitD, bile acids)

40

Gangliosides, cerebrosides are examples of what kind of lipids? Choline, Serine, and Inositol are ex of what lipids?

Sphingolipids.
glycerolphospholipids

41

Where does glycosylation take place?

ER and golgi. makes glycolipids and glycoproteins