Carboydrate Structure and Chemistry

Question 1

What is the function of glyceraldehyde?

Answer 1

An important intermediate in glycolysis and the pentose phosphate pathway

Question 2

What is the function of Dihydroxyacetone?

Answer 2

Its phosphate ester is an intermediate in glycolysis

Question 3

What is an important Tetrose monosaccharide?

Answer 3

Erythrose (aldose)

Question 4

What is the function of erythrose?

Answer 4

A pentose phosphate pathway intermediate

Question 5

What are the important pentose monosaccharides?

Answer 5

Aldose: D-ribose
Ketose: D-ribulose

Question 6

What is the function of D-ribose?

Answer 6

In its furanose form, it contributes to the structure of RNA and nucleotide coenzymes

Question 7

What is the function of D-ribulose?

Answer 7

Its phosphate ester, which is the most important ketopentose, is an intermediate in the pentose phosphate pathway

Question 8

What are the important Hexose monosaccharides?

Answer 8

Aldose: D-glucose, D-galactose, D-mannose
Ketose: D-fructose

Question 9

What is the function of D-glucose?

Answer 9

The most important aldohexose; it is the building block for glycogen, starch and cellulose. Free D-glucose is found in blood

Question 10

What is the function of D-galactose?

Answer 10

A constituent of lactose. Found in glycolipids and glycoproteins, along with D-mannose

Question 11

What is the function of D-fructose?

Answer 11

The most widely distributed ketohexose. It is a component of sucrose

Question 12

What is an important Heptose monosaccharide?

Answer 12

Ketose: Sedoheptulose

Question 13

What is the function of sedoheptulose?

Answer 13

An intermediate of the pentose phosphate pathway

Question 14

What are the important Triose aldose and Triose Ketose monosaccharides?

Answer 14

Glyceraldehyde and Dihydroxyacetone

Question 15

What is the structure of carbohydrates?

Answer 15

Cn (H2O) n

n = 3-9

Question 16

What is the simplest form of a CH? Give examples

Answer 16

monosaccharides

Glucose, fructose, galactose, ribose

Question 17

What form of CH consists of two monosaccharides? Give examples

Answer 17

disaccharides

Maltose, lactose, sucrosse

Question 18

What form of CH consists of 3-10 monosaccharides? Give examples

Answer 18

oligosaccharides

Glycolipids and glycoproteins

Question 19

What form of CH consists of greater than 10 monosaccharides? give examples

Answer 19

Polysaccharides

Glycogen, starch, cellulose

Question 20

What are the names of 3C, 4C, 5C, 6C, and 7C monosaccharides respectively?

Answer 20

Triose, tetrose, pentose, hexose, heptose

Question 21

Monosaccharide structure: if the carbonyl group is on the 2nd carbon it is a/an ______.

Answer 21

ketone

Question 22

Monosaccharide structure: if the carbonyl group is on the 1st carbon it is a/an ______.

Answer 22

Aldehyde

Question 23

What are stereoisomers?

Answer 23

same molecular formula and bond constituents but differ in spatial orientation of atoms attached to the asymmetric carbon

Question 24

What determines a monosaccharide D or L form?

Answer 24

OH group on the a carbon farthest away from carbonyl group

Question 25

What are epimers?

Answer 25

Diastereomers that differ in configuration of only on sterogenic (chiral) center

Question 26

What forms an asymmetric center?

Answer 26

4 different groups | *creates the mirror image

Question 27

Most sugars are in the __-series in human

Answer 27

D

Question 28

What is anomer?

Answer 28

The cyclic monosaccharides or glycosides that are epimers

Question 29

When -OH at C-1 is on the opposite side of the rign from the CH2OH it is a/an __ anomer

Answer 29

alpha

Question 30

A five carbon monosaccharide ring is called _____.

Answer 30

Furanose

Question 31

A six carbon monosaccharide ring is called _____.

Answer 31

pyranose

Question 32

True or false: The Fischer projection structure of a monosaccharide is more stable

Answer 32

False, The ring structure is more stable

Question 33

What modified monosaccharide is a major component of DNA?

Answer 33

Deoxyaldose

Question 34

What modified monosaccharides are components of glycoproteins and glycolipids? What do they play a major role in?

Answer 34

Acetylated amino sugars | Role: cell signaling, cell adhesion, immune response

Question 35

Acidic sugars are components of what?

Answer 35

Glycosaminoglycans and proteoglycans that are present in plasma membranes of cells and extracellular matrix

Question 36

What modified monosaccharide is created when a monosaccharide is attached to a phosphate group or sulfate group?

Answer 36

Sugar esters

Question 37

What modified monosaccharides constituted the gangliosides in oligodendrocyte of the nervous system and G6P is an example of this modified monosaccharide?

Answer 37

Sugar esters

Question 38

What creates sugar alcohols?

Answer 38

Carbonyl group is reduced, forming a hydroxyl group

Question 39

What are examples of sugar alcohols?

Answer 39

Glycerol, Xylitol, sorbitol

Question 40

What are the uses of sugar alcohols?

Answer 40

Food additives, gains importance in uncontrolled diabetes leading to cataracts and peripheral neuropathy; used in synthesis of lipids

Question 41

Carbohydrates are linked through what type of bond?

Answer 41

Either O or N - glycosidic bond | O is most common

Question 42

What is the nutritional reservoir of CH in plants?

Answer 42

Starch

Question 43

What is starch made of? what is the name of the branched and unbranched form of starch?

Answer 43

Glucose Amylopectin Amylose

Question 44

What is the natural sweetener?

Answer 44

Sucrose: Glucose and fructose

Question 45

What is the major dietary carb of animal origin?

Answer 45

Lactose: glucose and galactose | *Lactose intolerance: body can't easily digest lactose

Question 46

Starch amylose has what type of glycosidic bonds?

Answer 46

Alpha 1,4

Question 47

Amylose with the addition of branch points creates amylopectin: what is the glycosidic bond that creates these branches?

Answer 47

Alpha 1,6

Question 48

Cellulose is a major plant polysaccharide; what is the typical structure?

Answer 48

unbranched polymer of glucose residues joined by Beta 1,4 linkages.. Very long straight chains

Question 49

Why does starch and glycogen have bent structures?

Answer 49

More suitable for storage

Question 50

• Blood Glucose: regulated through the actions of hormones such as 1. _______ and _______. Normal fasting plasma glucose concentration range is 2. _________.; rarely exceeds 3. ________ after a meal. When blood glucose drops below 60 mg/dL (4._________) after a meal, 5. _____, _______, and ______ may be experienced. Below 40: 6. ____,____,_____, and _____. Fasting levels above ~130 and postprandial ~200 are diagnostic of 7________.

Answer 50

1. Insulin and glucagon 2. 70-100 mg/dL 3. 140 mg/dL 4. hypoglycemia 5. hunger, sweating, and trembling 6. convulsions, coma, brain damage, and death 7. diabetes mellitus

Question 51

Glycolysis: Process most cells generate energy. 6-C 1. ______ metabolized to 2 molecules of 3-C organic acid 2. ______. Net synthesis of 3. ____ ATP. Under aerobic conditions: pyruvate can be oxidized in 4. ______ to yield more energy (5. ___ ATP).

Answer 51

1. glucose 2. pyruvate 3. 2 4. mitochondria 5. 36

Question 52

What are the only means that cells obtain energy from glucose under anaerobic conditions?

Answer 52

Anaerobic conditions: glycolysis is the only means by which ATP can be generated from glucose. Cells that lack mitochondria rely only on glycolysis (RBCs).

Question 53

What is Pasteur effect?

Answer 53

Pasteur effect: aerobic conditions in other cells tend to suppress glycolysis in this phenomenon due to allosteric inhibition of glycolytic enzymes by citrate and ATP

Question 54

What is the Warburg effect

Answer 54

Warburg effect: many cancers exhibit high rates of glycolysis even in the presence of oxygen. This property is used in clinical detection of cancer by position emission tomography (PET)

Question 55

Describe erythritol

Answer 55

Erythritol: 4-carbon sugar alcohol used as artificial sweetener. Little metabolized, releases little energy when consumed in food. Doesn’t promote tooth decay. Absorbed and excreted in urine = less flatulence than other sugar alcohols

Question 56

Describe Xylitol

Answer 56

Xylitol: 5-C sugar alcohol used as natural sweetener. Low glycemic index. Doesn’t promote tooth decay. Lower energy content than sucrose but same sweetness. Does cause flatulence after excess

Question 57

Describe mannitol

Answer 57

Mannitol: energy storage by some micro-organisms and plants. Used to treat head trauma and kidney failure, heart-lung machine primer, make the blood-brain barrier permeable to drugs. Inhaled solid: treatment of cystic fibrosis by osmotically liquefying mucus. Low glycemic index, tooth-friendly sweetener, half as sweet as sucrose, high dose causes flatulence

Question 58

Describe sorbitol

Answer 58

Sorbitol: sweetener in chewing gum, tooth-paste, mouthwash and laxative

Question 59

(Carbs/lipids/proteins)_______ are synthesized from Acetyl CoA?

Answer 59

Lipids