Carbohydrates

Question 1

What are polymers?

Answer 1

Large, complex molecules composed of long chains of monomers joined together.

Question 2

What are monomers?

Answer 2

Monomers are small, basic molecular units.

Question 3

What are some examples of monomers?

Answer 3

monosaccharides, amino acids and nucleotides

Question 4

What elements do all carbohydrates contain?

Answer 4

C, H and O

Question 5

What are the monosaccharides that carbohydrates and made from called?

Answer 5

glucose, fructose, galactose

Question 6

How many carbons does glucose contain?

Answer 6

6 - it is a hexose sugar

Question 7

What is the diffrence between alpha glucose and beta glucose?

Answer 7

they have a diffrent arrangement of atoms. they have the H and OH, group reversed. H on top for alpha on rightside, OH on top for beta on the riightside.

Question 8

What is a condensation reaction?

Answer 8

two molecules join together with the formation of a new chemical bond, and a water molecule is realeased.

Question 9

How are Monosaccharides join together?

Answer 9

condensation reaction

Question 10

What is the bond called between to monosaccharides?

Answer 10

Glycosidic bond

Question 11

What is formed when two monosaccharides join together?

Answer 11

A disaccharide

Question 12

What do two molecules of alpha glucose form when joined up?

Answer 12

maltose

Question 13

What does fructose and glucose form when joined ?

Answer 13

Sucrose

Question 14

What does glucose and galactose form when joined?

Answer 14

Lactose

Question 15

How are polymers broken back down to monomers?

Answer 15

By a hydrolysis reaction

Question 16

What is a hydrolysis reaction?

Answer 16

Hydrolysis reaction breaks the chemical bond between monomers using a water molecule.

Question 17

What test is used for sugars?

Answer 17

Benedicts reagent

Question 18

What sugars are reducing sugars?

Answer 18

All monosaccharides and some disaccharides

Question 19

What do you do after adding benedicts reagent to a sample?

Answer 19

heat it in a water bath that been brought to the boil.

Question 20

What would happen if the test is positive for a reducing sugar?

Answer 20

the sample will turn coloured brick red or orange

Question 21

If the result for reducing sugars is negative what can you do?

Answer 21

a test for non reducing sugars

Question 22

How do you break up the sample into monosaccharides?

Answer 22

add dilute HCl and carefully heat it in a water bath thats been brought to boil. you can nuetralise it with sodium hydrogencarbonate.

Question 23

What do you do after you break up the monosaccharides in a non reducing sugar test?

Answer 23

carry out benedicts test normally

Question 24

How would you do if the test is postive for a non reducing sugar?

Answer 24

it will form a coloured precipitate, if the test is negative the solution will stay blue which means it does not contain a sugar( either reducing or non reducing).

Question 25

How is a polysaccharide formed?

Answer 25

it is formed when more than two monosccharides are joined together by a condensation reaction

Question 26

Where do cell get energy from?

Answer 26

glucose

Question 27

What do plants store excess glucose as?

Answer 27

starch (when a plant needs more glucose for energy, it breaks down starch to release the glucose)

Question 28

What are the two polysaccharides of alpha glucose that make up starch called?

Answer 28

amylose and amylopetin

Question 29

What is amylose?

Answer 29

a long, unbranched chain of alpha glucose. the angles of the glycosidic bonds give it a coiled structure, almost like a cylinder. this makes it compact so its really good for storage because you can fit more in to a small space.

Question 30

What is amylopectin?

Answer 30

a long, branched chain of alpha glucose. its side branches allow the enzymes that break down the molecule to get at the glycosidic bonds easily. this means that glucose can be released quickly.

Question 31

What is the test for starch?

Answer 31

Iodide

Question 32

What is a postive test for starch with iodide?

Answer 32

blue/black colour

Question 33

What do animals store execess glucose as?

Answer 33

glycogen

Question 34

What is the stucture of glucogen?

Answer 34

loads of branchs means that stored glucose can be released quickly, which is important for energy release in animals. it is also compact molecule so its a good storage molecule

Question 35

What is cellouse made up of?

Answer 35

long, unbranched chains of beta glucose

Question 36

What do beta molecules form when they bond?

Answer 36

staight cellouse chains

Question 37

What happens when the cellulose chains are linked together by hydrogen what do they provide?

Answer 37

they form strong fibers called microfibrils. the strong fibres mean cellulose provide structural support for cells