Exam 2: Carbohydrates

Question 1

What are 2 other names for carbohydrates

Answer 1

sugars, saccharides

Question 2

What are carbohydrates made of , what is the formula

Answer 2

C, H, O (CH2O)n

Question 3

What does n mean in the formula, what is the min

Answer 3

n= C must be at least 3

Question 4

What are the functions of carbs

Answer 4

energy source: glycolysis, Citric acid cycle, ETC
structural mol: cell membrane surface
signaling mol: also cell membrane surface

Question 5

What are the 7 types of rxns a carb can undergo

Answer 5

mutarotation: changes from alpha or beta to 6 or 5 member rings
oxidation: aldehyde or CH2OC can get oxidized or both.
reduction: aldehydes and ketones are reduced to alcohols
isomerization: rearrangements
esterification: an alcohol with anything attached to it can get transferred onto the carb. PO4 and SO4 can get added.
glycoside formation: hemiacetal and alcohol create acetal. or aldehyde
glycosylation: a sugar can get attached to a protein or lipid. OH of anomeric C binds to N or O in proteins

Question 6

Give examples of products of advanced and early glycosylation

Answer 6

early: carboxymethyllysine
advanced: pentosidine

Question 7

What are the 3 monosaccharide derivatives

Answer 7

uronic acids: group of CH2OH is oxidized
amino sugars: replace 1+ OH with an amine or multiple amines.
deoxy sugars: removal of OH for H

Question 8

What is an example of an lactone ring and why is it important

Answer 8

ascorbic acid vitamin C

Question 9

What is an example of a product you can get from glycoside formation rxns

Answer 9

salicin (aspirin on steroids)

Question 10

Give 2 examples of uronic acids where are they found

Answer 10

alpha-D-glucuronate produced in liver binds to big mols to make them more H2O sol
Beta-D-Iduronate: part of connective tissue helps with hydration

Question 11

What effect comes with an amino sugar

Answer 11

more charged, attracts more H2O

Question 12

What effect comes with an amino sugar

Answer 12

more charged, attracts more H2O

Question 13

What is a disaccharide?

Answer 13

2 monosaccharides bonded together to form a glycosidic bond

Question 14

What are 2 important examples of disaccharides?

Answer 14

lactose: in milk
beta cellobiose: degradation of cellulose in plants
sucrose: table sugar

Question 15

What kind of mol is lactose

Answer 15

a reducing sugar with a free anomeric C

Question 16

Why is lactose important in digestion

Answer 16

lactose = glucose + galactose. enzyme lactase breaks down lactose in intestines. If your body no longer produces lactase enzymes, you are lactose intolerant

Question 17

Where is the glycosidic bond in lactose located?

Answer 17

between OH of C1 on galactose and C4 on glucose

Question 18

What is a polysaccharide

Answer 18

polymer of mono or disaccharides 15-1000

Question 19

What is an oligosaccharide

Answer 19

a mini polysaccharide with 5-15 monosaccharides

Question 20

What are the 2 types of oligosaccharides

Answer 20

1) attached by N-link at N and Asp in protein

1) o linked: attached to protein through O in Ser or Thr

Question 21

Name 4 important large polymers

Answer 21

starch: storage mol in plants
glycogen: storage molecule in mammals
cellulose: structural in plants
chitin: structural in exoskeletons

Question 22

What is a homopolymer

Answer 22

polysaccharide made of 1 type of monosaccharide repeated

Question 23

what is a heteropolymer

Answer 23

polysaccharide with 2+ different monosaccharides

Question 24

Are the 4 large polymers homopolymers of heteropolymers? of what repeated molecule

Answer 24

homopolymers of glucose

Question 25

What what is the polymer of chitin

Answer 25

N-acetyl glucose amine

Question 26

What shape does chitin have, what kinds of bonds form

Answer 26

long straight chains that stack and form H bonds, per unit they form beta 1,4 glycosidic bonds

Question 27

What is the polymer of cellulose

Answer 27

glucose beta 1,4 glucose

Question 28

How are cellulose and chitin structurally different

Answer 28

cellulose does not have an acetyl amino group

Question 29

What shape is cellulose

Answer 29

long strands but more rigid

Question 30

Who is more rigid, cellulose or chitin, what makes them so rigid.

Answer 30

chitin is more. the beta 1.4 glycosidic bond allows for more H bonds in both mols

Question 31

of the 4 large polymers who is the most abundant on earth

Answer 31

cellulose

Question 32

What characteristics do both starch and glycogen have

Answer 32

act as glucose storage molecules non reducing end (no anomeric C) easier to break down than beta 1,4 linkage molecule

Question 33

What are the beta 1,4 linkage molecules and what are the alpha 1,4 linkage molecules

Answer 33

beta: cellulose and chitin | alpha glycogen and starch

Question 34

How are starch and glycogen different

Answer 34

starch can have kinks or branches every 20-25 monomers the bond is alpha 1,6 linkage starch is in plants glycogen is in mammals glycogen can have alpha 1,6 linkage every 8-12 monomers glycogen is more compact and takes up less space

Question 35

What is the polymer for starch and glycogen

Answer 35

alpha 1,4 glucose

Question 36

What are the 2 forms of polysaccharides that can occur in starch

Answer 36

amylose: unbranched, alpha 1,4 linkage only (forms left handed helix) amylopectin: branched with alpha 1,6 linkage as well as alpha 1,4 linkage

Question 37

where is glycogen found in mammals? Why is the structure convenient for mammals only?

Answer 37

mostly in liver and muscle cells. The compact structure makes energy mobilization from hydrolysis faster. compact structure also helps to be in mobile animal bodies

Question 38

What is a glycoconjugate

Answer 38

compounds that result from covalent linkages of carbs to both proteins and lipids

Question 39

What are the 2 types of glycoconjugates describe them

Answer 39

proteoglycans : mostly saccharides with some proteins | glycoproteins: mostly proteins with some saccharides

Question 40

What are the characteristics of proteoglycans

Answer 40

extremely high carb concentration have GAG chains and N and O glycosidic linkages produced in the golgi

Question 41

Question 7.5 which of the following sugars or sugar derivatives are reducing sugars? Which are capable of mutarotation? a) glucose b) fructose c) alpha methyl G glucoside d) sucrose

Answer 41

a) reducing can do mutarotation b) reducing can do mutarotation c) non reducing d) non reducing

Question 42

What is an example of a glycoprotein that is on the surface of eukaryotic cells

Answer 42

CAM cell adhesion molecules.

Question 43

What are the functions of glycoproteins

Answer 43

blood clotting factors, hormones, membrane proteins and can be enzymes

Question 44

What are the roles of galactose, glucose and fructose in living organisms

Answer 44

glucose: primary fuel for living cells fructose: often used as sweetening agent in food. galactose: synthesis of biomolecules like lactose.