carbohydrates

Question 1

with empirical formulas of (CH2O)n where n=3-7; derivatives include N, P and S; two major classes (aldose and ketose)

Answer 1

carbohydrates

Question 2

molecules with ‘n’ chiral centres will have ___ stereoisomers

Answer 2

2^n

Question 3

sugars that differ at on chiral centre

Answer 3

epimers

Question 4

3rd C is L

Answer 4

glucose

Question 5

3rd and 4th C are L

Answer 5

galactose

Question 6

cyclization results from aldehydes/ketones reacting with alcohols to form:

Answer 6

hemiacetals and hemiketals

Question 7

six membered sugar ring

Answer 7

pyranose

Question 8

five membered sugar ring

Answer 8

furanose

Question 9

carbon that becomes chiral as a consequence of cyclization; always carbonyl carbon

Answer 9

anomeric carbon

Question 10

hydroxyl of anomeric

carbon is below plane of sugar

Answer 10

alpha

Question 11

hydroxyl of anomeric carbon is above plane of sugar

Answer 11

beta

Question 12

in solution, a and b are in ____ and interconvert via _____

Answer 12

equilibrium; mutarotation

Question 13

mutarotation occurs through a ___ intermediate

Answer 13

linear

Question 14

found in both pyran and furan ring forms, pyran form being much sweeter than furan form

Answer 14

fructose

Question 15

___ b-fructopyranose makes it convert to the other form, becoming much less sweet

Answer 15

heating

Question 16

some plants contain this sugar derivative and enzyme, which are stored separately but come together when tissue is damaged to produce a bitter taste

Answer 16

glucosinolate and myrosinase

Question 17

which end of sugar is reducing end?

Answer 17

the sugar with an exposed anomeric carbon

Question 18

primary structural linkage in all polymers of monosaccharides

Answer 18

glycosidic bonds

Question 19

____ use monosaccharides activated thru link with UDP to create higher order carb structures

Answer 19

glycosyltransferases

Question 20

non-reducing sugar has this suffix

Answer 20

‘osyl’

Question 21

reducing sugar has suffix:

Answer 21

‘ose’

Question 22

lactose hydrolyzes into

Answer 22

glucose and galactose

Question 23

heavily hydrated structure; D-Glucose is stored intracellularly in this polymeric form in plants and fungi

Answer 23

starch (mix of unbranched amylose and branched amylopectin)

Question 24

heavily hydrated structure; D-Glucose stored intracellularly in this polymeric form in animals–>primarily found in liver and skeletal muscles

Answer 24

glycogen

Question 25

linear polymer of glucose residues through alpha(1-4) bonds; one reducing end and one non-reducing end

Answer 25

amylose

Question 26

alpha(1-4) glucose residues, with alpha(1-6) branch points every 24-30 residues; one reducing end and lots of nonreducing ends

Answer 26

amylopectin

Question 27

enzymes act on ____ ends

Answer 27

non reducing

Question 28

glycogen is structurally identical to amylopectin except:

Answer 28

it has a higher frequency of branching points, at every 10 residues, to allow faster mobilization

Question 29

primary component of plant cell walls; fibre; linear homopolysaccharide of glucose, with an arrangement of beta(1-4); fully extended molecule that is tough to pull apart; accounts for >1/2 C in biosphere!

Answer 29

cellulose

Question 30

principal component of exoskeletons; linear homopolysaccharide of N-acetylglucosamine residues (similar to cellulose but replace OH group at C2 with acetylated amino group)

Answer 30

chitin

Question 31

alpha(1-4) linkages form a hollow, ___ structure that provides a compact and accessible storage structure of glucose

Answer 31

helical

Question 32

beta(1-4) linkages allow formation of long, straight chains; ___ are formed by parallel chains linked by H bonds–>allows for rigid supportive structure of high tensile strength

Answer 32

fibrils

Question 33

help the body to discriminate self from non-self; blood group antigens

Answer 33

glycolipids

Question 34

proteins with covalently attached sugars; protein is largest component by weight

Answer 34

glycoproteins

Question 35

protein linked to a glycosaminoglycan carbohydrate; carbohydrate is largest component by weight; serves in structure and lubrication

Answer 35

proteoglycans

Question 36

carb usually > protein component, serve as lubricants in mucus; N-acetylglucosamine is predominant sugar in this; protect and hydrate epithelial cells

Answer 36

mucins

Question 37

sugars are attached to either the amide N of side chain of Asn (N-linked) or hydroxide O of side chain Ser or Thr (O-linked) through this reversible modification:

Answer 37

post-translational glycosylation

Question 38

glycoprotein found in serum that stimulates production of red blood cells; highly effective in treating anemia and exploited by endurance athletes

Answer 38

Erythropoietin (EPO)

Question 39

extracellular space contains a gel-like material called the extracellular matrix or ____

Answer 39

ground substance

Question 40

Holds cells together, provides porous path for diffusion of products, cushions; mesh of fibrous proteins and heteropolysaccharides called glycosaminoglycans

Answer 40

extracellular matrix

Question 41

unbranched heteroglycans, include amino sugar and alduronic acid, often have hydroxyl groups esterified with sulfate, covalently linked to extracell proteins to form proteoglycans

Answer 41

glycosaminoglycans