Carbohydrates

Question 1

what are the three types of carb molecules?

Answer 1

Monosaccharides. disaccharides and polysaccharides

Question 2

what are monosaccharides?

Answer 2

the single unit from which all other carbohydrates are made from - simple sugars

Question 3

what are the three main types of monosaccharides?

Answer 3

glucose, fructose and galactose

Question 4

what are structural isomers?

Answer 4

molecules that have the same molecular formula, but have a different arrangement in space

Question 5

what are the two structural isomers of glucose and how are they different?

Answer 5

alpha and beta glucose - different on the orientation of hydrogen and OH- groups on carbon 1

Question 6

what are disaccharides?

Answer 6

formed when two monosaccharides are joined together via a condensation reaction

Question 7

what is the bond that forms between monosaccharides called?

Answer 7

glycosidic bond

Question 8

what are the three different disaccharides?

Answer 8

maltose, sucrose and lactose

Question 9

maltose

Answer 9

alpha glucose

Question 10

sucrose

Answer 10

glucose and fructose

Question 11

lactose

Answer 11

glucose and galactose

Question 12

what is a hydrolysis reaction?

Answer 12

it’s a reaction which breaks a glycosidic bond between monomers using a water molecules

Question 13

what is a polysaccharide?

Answer 13

a giant molecule made up from more than two monosaccharides via a condensation reaction

Question 14

what are the three main polysaccharides?

Answer 14

starch, glycogen and cellulose

Question 15

describe starch

Answer 15

• a mixture of two ps of alpha glucose - amylose and amylopectin
• amylose - long/unbranched = has a coiled structure and it’s insoluble in water - ideal energy storage compound
• amylopectin - long/branched = it has side branches which have enzymes that break down the glycosidic bond = glucose is released quickly

Question 16

why is starch good for storage?

Answer 16

large molecule and it’s insoluble = has no osmotic effect on the cell

Question 17

describe glycogen

Answer 17

• main energy storage material in animals

- has more side branches than amylopectin

Question 18

describe cellulose

Answer 18

• made up of long unbranched of beta glucose molecules

- the beta glucose molecules join together = straight cellulose chains = linked by hydrogen bonds to form microfibrils

Question 19

what do the microfibrils do for cellulose?

Answer 19

they give cellulose strength, so it can provide structural support