carbohydrates

Question 1

what is a polymer?

Answer 1

many chemical units chemically bonded together

Question 2

what is a monomer?

Answer 2

a single chemical unit

Question 3

what are monosaccharides?

Answer 3

monomers (single sugar unit) from which larger carbohydrates are made

Question 4

what is a disaccharide?

Answer 4

two sugar units chemically bonded together

Question 5

what is a polysaccharide?

Answer 5

many sugar units chemically bonded together

Question 6

what does the chemical formula tell us?

Answer 6

which elements are present in a molecule and how many atoms of each element

Question 7

what does a structural formula tell us?

Answer 7

shows how the atoms are arranged and which atoms are bonded to other atoms

Question 8

what is a hydrolysis reaction?

Answer 8

a reaction where water is added to break a bond

Question 9

what is a glycosidic link?

Answer 9

a bond which links monosaccharides together

Question 10

what is a condensation reaction?

Answer 10

a reaction where water is removed to form a bond

Question 11

what are the three monosaccharides?

Answer 11

glucose
fructose
galactose

Question 12

what are the three disaccharides?

Answer 12

maltose
sucrose
lactose

Question 13

what are the three polysaccharides?

Answer 13

starch
cellulose
glycogen

Question 14

what are the main properties of mono and di, compared with poly?

Answer 14

mono and di; small +soluble
poly; large +insoluble

Question 15

what monosaccharides make up sucrose?

Answer 15

glucose and fructose

Question 16

what monosaccharides make up maltose?

Answer 16

glucose and glucose

Question 17

what monosaccharides make up lactose?

Answer 17

galactose and glucose

Question 18

what is the only non-reducing sugar we need to know about?

Answer 18

sucrose

Question 19

what is the only difference between alpha and beta glucose?

Answer 19

the H and OH on the right are flipped

Question 20

via what reaction are the monosaccharides joined to make a disaccharide?

Answer 20

condensation reaction

Question 21

what is a description of how two alpha glucose’s join to make maltose?

Answer 21

the hydroxyl group from one alpha glucose reacts with the hydroxyl group from another. Water is removed and a glycosidic link forms to produce the disaccharide maltose.

Question 22

which type of glucose is a molecule that curls up into a compact shape?

Answer 22

poly alpha glucose

Question 23

which type of glucose is a molecule that forms long fibrous chains?

Answer 23

Poly beta glucose

Question 24

which glucose does not form a complex with iodine?

Answer 24

poly beta glucose

Question 25

which glucose forms a helix into which an iodine molecule can fit?

Answer 25

poly alpha glucose
the complex formed absorbs most wavelengths of light

Question 26

which glucose matches this description; hydrogen bonds between - OH groups on glucose residues in the same chain into a specific shape?

Answer 26

poly alpha glucose

Question 27

which glucose matches this description; OH groups are not involved in hydrogen bonding between glucose residues in the same chain but are available for bonding to another chain.

Answer 27

poly beta glucose

Question 28

what is the formula for monosaccharides?

Answer 28

C6H12O6

Question 29

what is the test for reducing sugars?

Answer 29

1. add 2cm3 of the food sample to be tested to a test tube (must be in liquid form)
2. add equal volume of benedict’s
3. heat mixture gently in gently boiling water bath for 5 minutes
4. if reducing sugar is present solution turns from blue to green /yellow if amount is low and brick red if high