Carbohydrates

Question 0

orientation of the –H and –OH groups around the carbon atom adjacent to the terminal primary alcohol carbon determines whether the sugar belongs to the D (-OH on the left hand side) or L (-OH on the right hand side) series. True or false?

Answer 0

False. D pag right, L pag left

Question 1

Carbohydrates are aldehyde or ketone derivatives of monohydric alcohol. True or false?

Answer 1

False. Polyhydric dapat

Question 2

most sugars occurring in mammals are L sugars

Answer 2

False. D sugars dapat. L sugars:amino acid

Question 3

the ring structures of monosaccharides are similar to the ring structures of either pyran (a 5-membered ring) or furan (a 6-membered ring), true or false?

Answer 3

False. Pyran:6-membered ring + Furan:5-membered ring

Question 4

spontaneous interconversion of α and β anomers of a sugar

Answer 4

Mutarotation

Question 5

α-D-Glucopyranose has –OH group below the plane & β-D-Glucopyranose has –OH group above the plane. T or F?

Answer 5

T

Question 6

True of anomeric carbon atom

A.Cyclic structure exhibits isomerisms here
B.anomeric carbon atom is usually between two H atoms
C.also called carbonyl atom

Answer 6

B.anomeric carbon atom is usually between two H atoms

Usually between two O atoms siya

Question 7

the ring structure of an aldose is a hemiacetal, since it is formed by combination of an aldehyde and ___group. Similarly, the ring structure of a ketose is a hemiketal

Answer 7

An alcohol

Question 8

What are epimers?

Answer 8

isomers that differ in configuration at only 1 chiral center

Question 9

Which is false?
A. Glucose and mannose are epimers
B. Glucose and galactose are epimers
C. Galactose and mannose are epimers
D. All are true.

Answer 9

C. Galactose and mannose are epimers

galactose and mannose are NOT epimers – they differ in the position of –OH groups at two carbons

Question 10

Glucose and fructose exhibit aldose-ketose isomerism. Which is the aldose sugar and which is the ketose one?

Answer 10

Glucose-aldose

Fructose-ketose

Question 11

a hydrogenated form of carbohydrate whose carbonyl group is attached to a primary or secondary hydroxyl group. What is this??

Answer 11

Sugar alcohol

Question 12

Most popular sugar alcohol

Answer 12

xylitol

Question 13

Derivatives of monosaccharides may be utilized in glycolysis, pentose phosphate pathway and uronic acid pathway. True or false?

Answer 13

True

Question 14

Which is not found in the human body?
A.ribose
B.ribulose
C.lyxose
D.arabinose

Answer 14

Arabinose! It is found in wood gum.
Lyxose is found in heart muscle
Ribulose is formed in the pentose phosphate pathway

Question 15

compounds formed by condensation between the hydroxyl group of the anomeric carbon of a monosaccharide, and a second compound that may or may not be another monosaccharide.

Answer 15

Glycosides

Question 16

the extent to which starch in foods is hydrolyzed by amylase

Answer 16

Glycemic index

Question 17

Lower glycemic index means ___ breakdown of the carbohydrate

Slower,faster

Answer 17

Slower

Question 18

Why does our body store glycogen instead of glucose?

Answer 18

Glucose will be immediately consumed by the body unlike glycogen which can travel further without being utilized.

Question 19

Two types of glycosidic bonds

Answer 19

O-glycosidic

N-glycosidic

Question 20

• if sugar attaches to a ___ group in the non-carbohydrate molecule, the structure is an N-glycoside and the bond is an N-glycosidic bond

Answer 20

-NH

Question 21

[AMINO SUGARS]
Glucosamine – constituent of _____
Galactosamine – constituent of ___

Answer 21

first blank:hyaluronic acid

Second blank:chondroitin

Question 22

streptomycin contains __-glycosidic bond

Answer 22

O

Question 23

Maltose is made of what monosaccharides?how are they linked?

Answer 23

Glucose and glucose, C1 of one glucose is linked to C4 of the other

Question 24

False about lactose
A)glucose + galactose
B)with galactose having β-glycosidic bond with c-4 of glucose (called a β (1–>4) link)
C)not capable of mutarotation

Answer 24

C)not capable of mutarotation

Since it has free anomeric carbon, it is capable of mutarotation

Question 25

False about sucrose
A.two anomeric OH group of glucose and fructose have a glycosidic bonds - B.reducing sugar
C.glucose + fructose

Answer 25

B.reducing sugar

Question 26

What is the major sugar of insect hemolymph?

Answer 26

Trehalose

Question 27

Which is not a homopolysaccharide?
A.starch
B.chitin
C.cellulose
D.proteoglycan

Answer 27

D.proteoglycan

Proteoglycan: heteropolysaccharide

Question 28

Two chief components of starch

Answer 28

Amylose

Amylopectin

Question 29

Anong mas marami sa starch, amylose or amylopectin?

Answer 29

Amylopectin

Question 30

Glycogen is ___ (more,less) branched than amylopectin

Answer 30

More

Question 31

Most stable conformation of both starch and glycogen is __

Answer 31

Helix

Question 32

False about chitin
A)found in mollusks, crustaceans
B)important structural polysaccharide of invertebrates
C)consists of N-acetyl-D-galactosamine units

Answer 32

C)consists of N-acetyl-D-galactosamine units

Glucosamine dapat

Question 33

False about cellulose
A)homopolymer
B)chief constituent of the framework of bacteria
C)insoluble and consists of β(1,4) bonds forming long straight chains strengthened by cross-linked hydrogen bonds

Answer 33

B)chief constituent of the framework of bacteria

Plants dapat imbes na bacteria

Question 34

False about glycosaminoglycans
A)contain a repeating disacchaide unit: GalNAc or GlcNAc + glucoronate or iduronate
B)highly positively charged molecules, imparts high viscosity to the solution C)located primarily on the surface of cells or the extracellular matrix (ECM)

Answer 34

B)highly positively charged molecules, imparts high viscosity to the solution

Dapat imbes na positive,negative

Question 35

Proteoglycans are also called__

Answer 35

Mucopolysaccharides