1.7 Carbohydrate Structure and Digestion

Question 0

Two epimers of D-Glucose

Answer 0

D-Mannose (epimer at C-2)

D-Galactose (epimer at C-4)

Question 1

3 main categories of Carbohydrates

Answer 1

1. Monosaccharides
2. Oligosaccharides
3. Polysaccharides

Question 2

In the Hemi acetal (cyclic structure) what parts of the carbohydrate bond to each other to become cyclic

Answer 2

Carbonyl group covalently bonds to OH group

Question 3

T or F, The cyclic structure of Carbohydrates are more stable than open chain structure

Answer 3

True

Question 4

Pyranose has how many carbons involved in the ring?

Answer 4

6 membered ring

Question 5

Which is the less prevalent cyclic structure?

Answer 5

Furanose (5 membered rings)

Question 6

alpha linkages on anomeric carbon has the OH below or above the plane

Answer 6

Below

Question 7

Which anomeric linkage has the OH above the plane?

Answer 7

beta linkage

Question 8

What is a glycoside

Answer 8

It is technically a disaccharide. It is formed when OH group attached on an Anomeric carbon condenses with a group on another monosaccharide

Question 9

What type of linkages are involved with Starch?

Answer 9

alpha-1,4 and alpha-1,6.

Question 10

Cellulose has what type of linkages?

Answer 10

beta-1,4 linkages.

Question 11

Is Cellulose branched or unbranched

Answer 11

Unbranched

Question 12

What are the linkages of Glycogen

Answer 12

alpha-1,4 and alpha-1,6. Highly branched!

Question 13

What sugars are found in starch

Answer 13

Amylose (alpha-1,4) and Amylopectin (alpha-1,6)

Question 14

Where is Salivary Amylase found?

Answer 14

In the mouth

Question 15

What does Salivary Amylase digest?

Answer 15

alpha-1,4 linkages

Question 16

What enzyme of digestion is found in the lumen of small intestine

Answer 16

Pancreatic Amylase

Question 17

What are the digestion products of starch after it has been broken down by amylase?

Answer 17

Dextrins, Maltose, Isomaltose

Question 18

Name the brush border enzymes

Answer 18

Sucrase
Lactase
Maltase
Isomaltase

Question 19

Purpose of Brush border enzymes

Answer 19

Break down disaccharides to monosaccharides

Question 20

4 functions of Cellulose

Answer 20

1. Increase stool volume
2. Increase stool softness
3. Decrease transit time
4. Increase Satiety

Question 21

Two results of undigested carbohydrates (disaccharides?) passing into large intestine

Answer 21

1. Osmotic Diarrhea

2. Bacterial fermentation of carbs to 2 & 3 carbon fragments plus CO2 and H2 gas

Question 22

Sucrose is made up of what two sugars?

Answer 22

Glucose and Fructose

Question 23

Lactose is made up of what two sugars

Answer 23

Glucose and Galactose

Question 24

What sugars make up Cellulose

Answer 24

Glucose with beta-1,4 linkages

Question 25

Maltose sugars?

Answer 25

Glucose (alpha-1,4 linkages)

Question 26

Outline the association between oral bacteria, sucrose (carbs) and tooth decay

Answer 26

1. S. Mutans can cleave Sucrose into Fructose & Glucose
2. Fructose is used by the bacteria as a source of anaerobic energy
3. Glucose is polymerized into Dextran which helps attach bacteria to tooth enamel.
4. Dextran can be broken down into glucose producing lactic acid and tooth decay

Question 27

What is the most common disaccharidase deficiency

Answer 27

Lactase, Lactose intolerance