PCOG CARBS AND RELATED COMPOUNDS

Question 1

What are the two types of functional groups in carbohydrates?

Answer 1

Aldehyde and ketone.

Question 2

What is the general formula for carbohydrates?

Answer 2

C_n(H_2O)_n.

Question 3

What is the first product of photosynthesis?

Answer 3

Glucose.

Question 4

What are the two processes involved in the conversion of carbon dioxide and water during photosynthesis?

Answer 4

Reduction and oxidation.

Question 5

How are carbohydrates classified?

Answer 5

Into monosaccharides, disaccharides, and polysaccharides.

Question 6

What are homoglycans?

Answer 6

Polysaccharides made of only one type of sugar, such as starch and cellulose.

Question 7

What are heteroglycans?

Answer 7

Polysaccharides made of different types of sugars, such as gums and mucilage.

Question 8

What is the most important monosaccharide in plants?

Answer 8

Hexoses.

Question 9

What distinguishes aldoses from ketoses?

Answer 9

Aldoses contain an aldehyde group, while ketoses contain a ketone group.

Question 10

What is the simplest natural aldose?

Answer 10

Glyceraldehyde.

Question 11

What is the cyclic configuration of glucose called?

Answer 11

Haworth projection.

Question 12

What is an anomeric carbon?

Answer 12

A carbon that has two oxygens and determines the alpha or beta configuration.

Question 13

How many isomers can glucose have based on its chiral carbons?

Answer 13

16 isomers (2^4).

Question 14

What is a diastereomer?

Answer 14

Compounds that differ in 2 or more chiral carbons, e.g., arabinose and xylose (C2, C3).

Question 15

What is an epimer?

Answer 15

Compounds that differ in only 1 chiral carbon, e.g., arabinose and ribose (C2), glucose and mannose (C2).

Question 16

What are enantiomers?

Answer 16

Mirror images of each other where all chiral carbons are switched, e.g., rhamnose and mannose.

Question 17

What type of sugar is glucose?

Answer 17

An aldohexose with an aldehyde group in C1 and a reducing sugar.

Question 18

What is the only utilizable sugar in the blood?

Answer 18

Glucose.

Question 19

What is the natural source of glucose?

Answer 19

Grapes.

Question 20

What is fructose commonly known as?

Answer 20

Fruit sugar or levulose.

Question 21

What is the sweetest monosaccharide?

Answer 21

Fructose.

Question 22

What is galactose and where is it found?

Answer 22

An aldohexose found in milk (as lactose) and neuronal fibers (as galactoceramides).

Question 23

What condition affects the body’s ability to convert galactose to glucose?

Answer 23

Galactosemia.

Question 24

What are natural sources of xylose (wood sugar)?

Answer 24

Corn cobs, straws, heartwood of deciduous trees, and other materials soaked in dilute acids to hydrolyze xylan.

Question 25

What is the primary use of xylose?

Answer 25

As a diagnostic aid for intestinal malabsorption.

Question 26

What are disaccharides composed of?

Answer 26

Two monosaccharide units.

Question 27

How are disaccharides formed?

Answer 27

Via dehydration synthesis, forming ether glycosidic bonds.

Question 28

What is sucrose composed of?

Answer 28

Glucose and fructose, linked by a β-1,2 glycosidic bond.

Question 29

What is a characteristic of sucrose?

Answer 29

It is a non-reducing sugar.

Question 30

What are the natural sources of sucrose?

Answer 30

Sugar cane, sugar beet, and sugar maple.

Question 31

What is trehalose and where is it found?

Answer 31

A disaccharide composed of glucose + glucose, found in brown seaweed and fungi.

Question 32

What is maltose commonly known as?

Answer 32

Malt sugar or beer sugar.

Question 33

What is the primary use of maltose?

Answer 33

As a component in beers.

Question 34

What is lactose derived from?

Answer 34

Fresh cow's milk and the crystallization of whey, a by-product of cheese production.

Question 35

What is the glycosidic bond in lactose?

Answer 35

α-1,4 glycosidic bond between glucose and galactose.

Question 36

What causes lactose intolerance?

Answer 36

Absence of the enzyme lactase or β-galactosidase.

Question 37

What is condensed milk?

Answer 37

Partially evaporated milk.

Question 38

What is malted milk?

Answer 38

Milk evaporated with malt extract from barley.

Question 39

What is Kumyss?

Answer 39

An alcoholic beverage made from fermented mare's milk, originally made by nomads of Central Asia.

Question 40

What is lactulose and its primary use?

Answer 40

A synthetic sugar used as a laxative (e.g., Duphalac®).

Question 41

How does lactulose affect blood ammonia concentration?

Answer 41

It decreases blood ammonia concentration in portal-systemic encephalopathy by trapping ammonia as NH4+.

Question 42

What are tautomers?

Answer 42

Constitutional isomers of organic compounds that readily interconvert in a rapid equilibrium.

Question 43

What is the most common tautomeric relation in organic chemistry?

Answer 43

The keto-enol pair.

Question 44

What are oligosaccharides?

Answer 44

Carbohydrates that have 3-10 sugar units.

Question 45

What is maltotriose composed of?

Answer 45

Three glucose units.

Question 46

What are dextrins?

Answer 46

Products of partial hydrolysis of starch, formed by amylase and glucosidase.

Question 47

What is the role of α-glucosidase inhibitors?

Answer 47

They inhibit the conversion of limiting dextrins to glucose, preventing post-prandial increases in glucose levels.

Question 48

What is raffinose composed of?

Answer 48

Glucose, galactose, and fructose.

Question 49

What are polysaccharides?

Answer 49

Carbohydrates that consist of more than 10 sugar units, used for storage or structure.

Question 50

What is the primary storage polysaccharide in plants?

Answer 50

Starch.

Question 51

What is the primary storage polysaccharide in animals?

Answer 51

Glycogen.

Question 52

What are homoglycans made up of?

Answer 52

One type of sugar only.

Question 53

What is the temporary storage form of photosynthetic products in plants?

Answer 53

Starch (glucosan).

Question 54

Name two natural sources of starch.

Answer 54

Corn grain (Zea mays) and potato tubers (Solanum tuberosum).

Question 55

What are the two structurally different polysaccharides that make up starch?

Answer 55

Amylose and amylopectin.

Question 56

What is the iodine test result for amylose?

Answer 56

Deep blue.

Question 57

What is the primary use of pregelatinized starch?

Answer 57

As a tablet excipient.

Question 58

What is the end product of α-amylases?

Answer 58

A mixture of glucose, maltose, and amylopectin.

Question 59

What is glycogen's role in animals?

Answer 59

Storage form of carbohydrates.

Question 60

How frequently does glycogen branch compared to starch?

Answer 60

Every 10 units, more highly branched than starch.

Question 61

What is the iodine test result for glycogen?

Answer 61

Wine red.

Question 62

What is inulin primarily composed of?

Answer 62

A polymer of fructose.

Question 63

What is one use of inulin?

Answer 63

To measure renal glomerular filtration.

Question 64

What type of bonds link glucan in dextran?

Answer 64

ɲ - (1 o 6) bonds with some branching due to ɲ - (1 o 3).

Question 65

What enzyme is responsible for converting sucrose to dextran?

Answer 65

Dextran sucrase/transglycosylase.

Question 66

What is a common use of dextran?

Answer 66

As a plasma expander at 10%.

Question 67

What is cellulose primarily responsible for in plant cell walls?

Answer 67

Rigidity.

Question 68

Why can't mammals digest cellulose?

Answer 68

They lack cellulase.

Question 69

What is the natural source of cellulose?

Answer 69

Cotton (Gossypium hirsutum).

Question 70

What is methylcellulose used for?

Answer 70

As a bulk laxative and suspending agent.

Question 71

What is the function of ethylcellulose?

Answer 71

As a tablet binder and film coat.

Question 72

What is chitin a homopolymer of?

Answer 72

N-acetyl-ɴ-D-glucosamine.

Question 73

What are heteroglycans made of?

Answer 73

Different types of sugar.

Question 74

What are gums and mucilage classified as?

Answer 74

Natural plant hydrocolloids.

Question 75

What is the primary function of gums in plants?

Answer 75

As a protective agent after injury.

Question 76

What are the components of gum tragacanth?

Answer 76

Bassorin (60-70%) and tragacanthin (30-40%).

Question 77

What is the best grade of tragacanthin and bassorin for use as a suspending agent?

Answer 77

Low tragacanthin and high bassorin.

Question 78

What is the primary use of Acacia gum?

Answer 78

As a suspending agent (35%).

Question 79

What is the exudate from Acacia senegal known as?

Answer 79

Gum arabic.

Question 80

What type of gum is Karaya gum and what is its primary use?

Answer 80

It is an exudate from Sterculia urens, used as a bulk laxative.

Question 81

What is the source of sodium alginate?

Answer 81

Brown seaweeds, specifically Macrocystis porifera.

Question 82

What are the components of agar?

Answer 82

Agarose and agaropectin.

Question 83

What is the primary use of carrageenan?

Answer 83

As a thickener and gelling agent.

Question 84

What is the main property of xanthan gum?

Answer 84

It possesses pseudoplastic properties.

Question 85

What is pectin derived from?

Answer 85

The inner portion of the rind of citrus fruits or from apple pomace.

Question 86

What is the role of dextran in medical applications?

Answer 86

It is used as a plasma expander.

Question 87

What is pectic acid?

Answer 87

An insoluble degradation product of overripe fruits.

Question 88

What is chondroitin sulfate used for?

Answer 88

As a supplement for osteoarthritis to maintain elasticity of cartilage joints.

Question 89

What is the role of hyaluronic acid?

Answer 89

It lubricates synovial fluid and is used in dermatology for anti-aging and anti-wrinkle treatments.

Question 90

What is heparin and its primary function?

Answer 90

A natural anticoagulant that inhibits the action of thrombin.

Question 91

What are sugar alcohols?

Answer 91

Reduction or hydrogenation products of sugars, such as sorbitol and mannitol.

Question 92

What is the polyol pathway?

Answer 92

A metabolic pathway where glucose is converted to sorbitol by aldose reductase.

Question 93

What can excess sorbitol lead to in diabetics?

Answer 93

Depletion of NADPH levels, lower antioxidant activity, and possible oxidative damage to cells.

Question 94

What is the effect of NADPH in the body?

Answer 94

It activates glutathione and is involved in the pentose phosphate pathway.

Question 95

What is the significance of chitin?

Answer 95

It is composed of N-acetylgalactosamine and comprises the shells of crustaceans.

Question 96

What is the main cause of incompatibilities in cherry juice preparations?

Answer 96

Pectin.

Question 97

What is the only plant acid that does not carbonize when heated?

Answer 97

Malic acid.

Question 98

What is the use of malic acid in cherry juice?

Answer 98

Preparation of cherry syrup to mask the taste of sour drugs.

Question 99

What are plant acids?

Answer 99

Aliphatic organic acids from plants with 2 to 6 carbon atoms and 2 or 3 carboxyl groups.

Question 100

What is the ratio of citric acid to tartaric acid in effervescent tablet formulation?

Answer 100

1 part citric acid to 2 parts tartaric acid.

Question 101

Which acid is a by-product of the wine industry?

Answer 101

Tartaric acid.

Question 102

What is the oxidation product of ethylene glycol poisoning?

Answer 102

Oxalic acid (forms calcium oxalate crystals).

Question 103

What is the precursor of aromatic compounds and amino acids?

Answer 103

Shikimic acid.

Question 104

Which acid is known as the cheapest antioxidant but is very unstable?

Answer 104

Ascorbic acid.