Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IOCH14B > Carbohydrates > Flashcards

Carbohydrates Flashcards

1
Q

The word carbohydrate arose because molecular formulas of these compounds can be expressed as

A

hydrates of carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The chemistry of carbohydrates is mainly the combined chemistry of two functional groups:

A

hydroxyl group and the carbonyl group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Carbohydrates are-_____,______, or substances that give such compounds on hydrolysis

A

polyhydroxyaldehydes, polyhydroxyketones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

usually classified according to their structure as monosaccharides, oligosaccharides, or polysaccharides.

A

Carbohydrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The term saccharide comes from Latin (_____, _____) and refers to the sweet taste of some simple carbohydrates

A

saccharum, sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The three classes of carbohydrates are related to each other through hydrolysis.

A

Monosaccharides, Polysaccharides, and Oligosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

(or simple sugars, as they are sometimes called) are carbohydrates that cannot be hydrolyzed to simpler compounds

A

Monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

contain many monosaccharide units—sometimes hundreds or even thousands. Usually, but not always, the units are identical. Two of the most important ___________, starch and cellulose, contain linked units of the same monosaccharide, glucose.

A

Polysaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

(from the Greek oligos, few) contain at least two and generally no more than a few linked monosaccharide units. They may be called disaccharides, trisaccharides, and so on, depending on the number of units, which may be the same or different.

A

Oligosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Monosaccharides are classified according to the number of carbon atoms present (triose, tetrose, pentose, hexose, and so on) and according to whether the carbonyl group is present as an ________or______

A

aldehyde (aldose) or as a ketone (ketose).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

There are only two trioses in Monosaccharides

A

glyceraldehyde and dihydroxyacetone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

the simplest aldose

A

glyceraldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

the simplest ketose

A

dihydroxyacetone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

used a capital D to represent the configuration of (+)-glyceraldehyde, with the hydroxyl group on the right; its enantiomer, with the hydroxyl group on the left, was designated L-(-)-glyceraldehyde. The most oxidized carbon (CHO) was placed at the top.

A

Emil Fischer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

If the stereogenic carbon farthest from the aldehyde or ketone group had the same configuration as D-glyceraldehyde (hydroxyl on the right), the compound was called a

A

D-sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

If the configuration at the remote carbon had the same configuration as L-glyceraldehyde (hydroxyl on the left), the compound was an

A

L-sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

These structures are called _____forms after the six-membered oxygen heterocycle pyran

A

pyranose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

formed by reaction of the hydroxyl group at C-5, with the carbonyl group. With some sugars, however, the hydroxyl group at C-4 reacts instead.

A

pyranoses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

type of cyclic monosaccharide is called a_____, after the parent five-membered oxygen heterocycle furan

A

furanose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The most common oligosaccharides

A

disaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In a disaccharide, two monosaccharides are linked by a __________ between the anomeric carbon of one monosaccharide unit and a hydroxyl group on the other unit

A

glycosidic bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

the disaccharide obtained by the partial hydrolysis of starch.

A

Maltose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

hydrolysis of maltose gives only

A

D-glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

the disaccharide obtained by the partial hydrolysis of cellulose.

A

Cellobiose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Further hydrolysis of cellobiose gives only

A

D-glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

the major sugar in human and cow’s milk (4% to 8% _____)

A

lactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Hydrolysis of lactose gives equimolar amounts of

A

D-galactose and Dglucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q
  • Some human infants are born with a disease called
  • They lack the enzyme that isomerizes galactose to glucose and therefore cannot digest milk. If milk is excluded from such infants’ diets, the disease symptoms caused by accumulation of galactose can be avoided
A

galactosemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

The most important commercial disaccharide

A

Sucrose

30
Q

More than_______ are produced annually worldwide. Sucrose occurs in all photosynthetic plants, where it functions as an energy source.

A

130 million tons

31
Q

It is obtained commercially from sugar cane and sugar beets, in which it constitutes ___ %to ___% of the plant juices

A

14% to 20%

32
Q

very water soluble (2 grams per milliliter at room temperature) because it is polar due to the presence of eight hydroxyl groups on its surface

A

Sucrose

33
Q

Hydrolysis of sucrose gives equimolar amounts

A

D-glucose and the ketose D-fructose.

34
Q

contain many linked monosaccharides and vary in chain length and molecular weight.

A

Polysaccharides

35
Q

Most polysaccharides give a ______ on complete hydrolysis.

A

single monosaccharide

36
Q

the energy-storing carbohydrate of plants. It is a major component of cereals, potatoes, corn, and rice.

A

starch

37
Q

It is the form in which glucose is stored by plants for later use

A

starch

38
Q

Starch is made up of glucose units joined mainly by ________, although the chains may have a number of branches attached through 1,6-α-glycosidic bonds

A

1,4-α-glycosidic bonds

39
Q

Partial hydrolysis of starch gives maltose, and complete hydrolysis gives only

A

D-glucose

40
Q

Starch can be separated by various techniques into two fractions:

A

amylose and amylopectin

41
Q

which constitutes about 20% of starch, the glucose units (50 to 300) are in a continuous chain, with 1,4 linkages.

A

amylose

42
Q

highly branched. Although each molecule may contain 300 to 5000 glucose units, chains with consecutive 1,4 links average only 25 to 30 units in length. These chains are connected at branch points by 1,6 linkages.

A

Amylopectin

43
Q

the energy-storing carbohydrate of animals

A

Glycogen

44
Q

Like starch, it is made of ____and____ glucose units. Glycogen has a higher molecular weight than starch (perhaps 100,000 glucose units), and its structure is even more branched than that of amylopectin, with a branch every 8 to 12 glucose units

A

1,4- and 1,6-linked

45
Q

produced from glucose that is absorbed from the intestines into the blood; transported to the liver, muscles, and elsewhere; and then polymerized enzymatically

A

glycogen

46
Q

an unbranched polymer of glucose joined by 1,4-b-glycosidic bonds

A

Cellulose

47
Q

X-ray examination of cellulose shows that it consists of linear chains of cellobiose units in which the ring oxygens alternate in “______” and “______” positions.

A

forward and backward

48
Q

Many bacteria, however, do contain b-glucosidases and can hydrolyze cellulose. Termites, for example, have such bacteria in their intestines and thrive on wood (cellulose) as their main food. Ruminants (cud-chewing animals such as cows) can digest grasses and other forms of cellulose because they harbor the necessary microorganisms in their ______

A

rumen

49
Q

a nitrogen-containing polysaccharide that forms the shells of crustaceans and the exoskeletons of insects.

A

chitin

50
Q

which are obtained from fruits and berries, are polysaccharides used in making jellies.

A

Pectins

51
Q

has the same structure as D-galactose, except that the C-6 primary alcohol group is replaced by a carboxyl group.

A

D-Galacturonic acid

52
Q

one or more of the hydroxyl groups is replaced by a hydrogen atom.

A

Deoxy Sugars

53
Q

The most important example is 2-deoxyribose

A

the sugar component of DNA.

54
Q

one of the sugar hydroxyl groups is replaced by an amino group.

A

Amino Sugars

55
Q

one of the more abundant amino sugars.

A

D-Glucosamine

56
Q

b-D-glucosamine the monosaccharide unit of chitin, which forms the shells of lobsters, crabs, shrimp, and other shellfish.

A

N-acetyl form

57
Q

more precisely in terms of their organic structures

A

carbohydrates

58
Q

the chain numbered from the aldehyde carbon

A

aldoses

59
Q

the carbonyl group is located at C-2

A

ketoses

60
Q

The most oxidized carbon -_____ was placed at the top.

A

CHO

61
Q

“convert D-glucose to the cyclic a-pyranose form as a Haworth projection”

A

Converting a Fischer Projection to A Haworth Projection

62
Q

some “tricks” for converting a Fischer to a Haworth

For C1: the a anomer has OH →

A

down (for D-sugars)

63
Q

some “tricks” for converting a Fischer to a Haworth

For C1: the B anomer has OH →

A

up (for D-sugars)

64
Q

In Maltose, The ________of the left unit is linked to the C-4 _______of the unit at the right

A

anomeric carbon & hydroxyl group

65
Q

cellobiose differs from maltose only in having the b-configuration at ____ of the left glucose unit. Otherwise, all other structural features are identical, including a link from C-1 of the left unit to the hydroxyl group at ___ in the right unti.

A

C-1 & C-4

66
Q

Lactose, The anomeric carbon of the galactose unit has the b configuration at____and is linked to the hydroxyl group at ___ of the glucose unit.

A

C-1 & C-4

67
Q

Sucrose differs from the other disaccharides in that the anomeric carbons of both units are involved in the glycosidic bond; that is,___ of the glucose unit is linked via oxygen to ___ of the fructose unit..

A

C-1 & C-2

68
Q

Sucrose, an additional difference is that the fructose unit in the ____

A

furanose form

69
Q

Amino sugars: ______is also acetylated

A

NH2 group

70
Q

The main function of carbohydrate is a _____

A

short term energy

IOCH14B (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions