Intro to Carb Metabolism

Question 1

In what direction does the hydroxyl point in an alpha conformation? A beta conformation?

Answer 1

Alpha is down

Beta is up

Question 2

What is amylose? What types of linkages are present? Is it linear or branched?

Answer 2

Starch, polysaccharide, with alpha -1,4 linkages, linear

Question 3

What is amylopectin? What types of linkages are present? Is it linear or branched

Answer 3

Starch, polysaccharide, with alpha- 1,4 linkages and alpha 1-6 linkages, branched

Question 4

What two monosaccharides make up lactose? What is the linkage?

Answer 4

Glucose and galactose, beta-1,4

Question 5

What is glycogen? What types of linkages are present? Is it linear or branched?

Answer 5

Polysaccharide, alpha-1,4 and alpha-1,6, highly branched (more than amylopectin)

Question 6

What is cellulose? What are the linkages? is it linear or branched?

Answer 6

Polysaccharide, beta-1,4, linear

Can’t be digested because we dont have the enzyme

Question 7

Glycosidases are extremely specific. What factors attribute to this specificity?

Answer 7

1. the specific orientation of the linkage (alpha or beta)
2. Specific molecule involved
3. Position of the bond

Question 8

What type of glycosidase is alpha-amylase?

Answer 8

endoglycosidase that hydrolyzes internal alpha-1,4 linkages

Question 9

What is the difference between salivary alpha amylase and pancreatic alpha amylase?

Answer 9

Salivary amylase cleaves polysaccharides into smaller polysaccharides and gets inactivated in the stomach
Pancreatic amylase cleaves polysaccharides into disaccharides

Question 10

Where do you get the cleavage of disaccharides to monosaccharides?

Answer 10

Brush border secreted by the epithelial cells

Question 11

What glycosidic bond does glucoamylase cleave? What are the products?

Answer 11

Cleaves an alpha-1,4 bond that produces glucose and isomaltose

Question 12

What bond does maltase cleave? What are the products?

Answer 12

Cleaves alpha-1,4 to give maltose and glucose

Question 13

What bond does isomaltase cleave? What are the products?

Answer 13

Cleaves alpha-1,6 to give glucose and glucose polymers

Question 14

What bond does sucrase cleave? What are the products?

Answer 14

Cleaves alpha-1,2 to give fructose and glucose

Question 15

What bond does lactase (beta-galactosidase) cleave? What are the products?

Answer 15

Cleaves beta-1,4 to give galactose and glucose

Question 16

What causes lactose intolerance?

Answer 16

Shortage of lactase

Question 17

True or False: both the liver and skeletal muscle do glucogenolysis and gluconeogenesis

Answer 17

False -only liver

Question 18

What happens first, glucogenolysis or gluconeogenesis?

Answer 18

Glucogenolysis