CARBOHYDRATES CHAPTER 3

Question 1

what happens when an anomeric carbon of a carbohydrates reacts with an OH group in a slightly acidic conditions

Answer 1

a glycosidic bond is formed with the release of water (condensation)

Question 2

what is the description and component monosaccharides of sucrose?

Answer 2

-common table sugar
-glucose1a > 2 fructose

Question 3

what is the description and component monosaccharides of maltose

Answer 3

-product of starch hydrolysis
-glucose 1a > 4 glucose

Question 4

what is the description and component monosaccharides of trehalose

Answer 4

-found in fungi
-glucose 1a > 1 glucose

Question 5

what is the description and component monosaccharides of lactose

Answer 5

-main sugar in milk
-galactose 1b > 4 glucose

Question 6

what is the description and component monosaccharides of melibiose

Answer 6

-found in legumes
-galactose 1a > 6 glucose

Question 7

what are the functions of polysaccharide-complex sugar

Answer 7

-storage
-structural material
-connective tissue
-cell identification
-bacteria cell wall

Question 8

example of polysaccharide-complex sugar that functions as structural material

Answer 8

cellulose, hemicellulose, pectin, chitin, dextran, inulin

Question 9

example of polysaccharide-complex sugar that functions as storage

Answer 9

starch and glycogen

Question 10

example of polysaccharide-complex sugar that functions as connective tissue

Answer 10

glycosaminoglycan - i.e hyaluronic acid, chondroitin sulphate, heparin, dermatan sulphate, keratan sulphate

Question 11

example of polysaccharide-complex sugar that functions as cell identification

Answer 11

glycoprotein > proteoglycan

Question 12

example of polysaccharide-complex sugar that functions as bacteria cell wall

Answer 12

polysaccharides

Question 13

where are glycogen and starch stored?

Answer 13

granules in cells

Question 14

what storage are starch and glycogen for?

Answer 14

starch = plants
glycogen = animals

Question 15

main units of starch

Answer 15

amylose & amylopectin

Question 16

what kind of molecules are amylose, amylopectin and glycogen

Answer 16

-amylose = a linear molecule (a 1-4)
-amylopectin & glycogen = branched polymers (a 1-4 & a 1-6)

Question 17

what is cellulose

Answer 17

-major polysaccharide in woody and fibrous plants
-single most abundant single polymer in the biosphere

Question 18

what enzyme can digest cellulose

Answer 18

cellulase

Question 19

what type of polymer is cellulose

Answer 19

linear polymer of D-glucose

Question 20

what linkage exist in cellulose?

Answer 20

B(1-4) glycoside

Question 21

what are the components that are bonded to cellulose?

Answer 21

hemicellulose, pectin & lignin in plant cell walls

Question 22

what other bond exist in cellulose

Answer 22

lots of hydrogen bonds occur in cellulose microfibrils (this is what make cellulose very strong n why human cant digest them)

Question 23

what does each microfibrils consist of?

Answer 23

each microfibril consist of 50-100 cellulose molecules

Question 24

what can cellulose also exist as?

Answer 24

Cellulose can exist as fully extended chains, with each glucose residue flipped by 180° with respect to its
neighbour

Question 25

where can chitin be found

Answer 25

in exoskeletons of invertebrates, spiders, insects and crustaceans

Question 26

what is the monomer of chitin

Answer 26

amino sugar N-acetyl glucosamine that is linked by B(1-4) bonds

Question 27

what is chitin used for

Answer 27

Chitin is used in the food industry – to prolong shelf life of fruits & chitin linked to Fe is used to delay meat from going bad

Question 28

what is deacetylated chitin?

Answer 28

Deacetylated chitin = Chitosan, used as filter in industries, in bandages as it clots blood rapidly, attract
fats (used in slimming) etc

Question 29

what is dextran made of?

Answer 29

glucose linked in α 1→6 fashion with α 1→2,
1→3, 1→4 side chains.

Question 30

where is dextran found in?

Answer 30

Found in yeast and bacteria.

Question 31

functions of dextran?

Answer 31

• Main carbohydrate/component in dental plaque.
• Dextran are also used commonly by surgeons to decrease vascular thrombosis (formation of a clot in
  blood vessels)

Question 32

what is inulin

Answer 32

a plant polysaccharide for storage function

Question 33

is inulin a polymer?

Answer 33

yes it is a polymer of fructose linked in B(2>1) fashion

Question 34

functions of inulin

Answer 34

• A lot in onions, yam, garlic, in roots or rhizomes of plants.
• Inulin is used increasingly in foods because it has unusual nutritional characteristics. It ranges from completely blend to subtly sweet and can be used to replace sugar. It is suitable for diabetics because it has 1/4 to 1/3 energy of sugar.
• Inulin is also used to help measure kidney function by determining the glomerular filtration rate (GFR).

Question 35

what is a glycosaminoglycan

Answer 35

polysaccharide found in the intercellular spaces between cells in tissues (extracellular) like cartilage, tendon, skin, arterial wall etc.

Question 36

importance of glycosaminoglycan

Answer 36

structurally important in vertebrate animals

Question 37

major functions of glycosaminoglycan

Answer 37

formation of matrix to hold together proteins components of skin and connective tissue

Question 38

what is glycosaminoglycan made of

Answer 38

• Made up of a long chain of repetitive disaccharide units, ex:
  chondroitin sulphate;
• Each disaccharide unit is made up of an amino sugar and a monosaccharide with a negatively charged (–ve) sulphate or
  carboxylate group (sugar acid).
• Several types – hyaluronate, heparin, chondroitin 4 sulphate,
  chondroitin 6 sulphate, dermatan sulphate, keratan sulphate