paper 1: Monomers, Polymers: Carbohydrates

Question 1

define a monomer

Answer 1

smaller, soluble molecules from which larger molecules are made

Question 2

define a polymer

Answer 2

molecules made from many similar monomers joined together

Question 3

why are lipids not polymers

Answer 3

they don’t contain similar monomers

Question 4

what is the monomer and polymer of a carbohydrate called

Answer 4

monomer: monosaccharide
polymer: polysaccharide

Question 5

what is the monomer and polymer of a protein called

Answer 5

monomer: amino acid
polymer: polypeptide

Question 6

what is the monomer and polymer of DNA/RNA called

Answer 6

monomer: nucleotide
polymer: polynucleotide

Question 7

describe what happens during a condensation reaction

Answer 7

a condensation reaction joins two molecules together with the formation of a chemical bond and involves the elimination of a water molecule.

Question 8

describe what happens during a hydrolysis reaction

Answer 8

a hydrolysis reaction breaks a chemical bond between 2 molecules and involves the use of a water molecule.

Question 9

what is a monosaccharide and name 3 examples.

Answer 9

monomers from which larger carbohydrates are made.
glucose, fructose, galactose

Question 10

describe a disaccharide and give 3 examples

Answer 10

2 monosaccharides joined together by a glycosidic bond which form during a condensation reaction
maltose, sucrose, lactose

Question 11

describe a polysaccharide and give 3 examples

Answer 11

formed by the condensation of many repeating monosaccharides
starch, glycogen, cellulose

Question 12

what is an isomer

Answer 12

molecules with the same chemical formula but different structural formula.

Question 13

what is the chemical formula for glucose

Answer 13

C6H12O6

Question 14

name the two isomers of glucose

Answer 14

alpha glucose, beta glucose

Question 15

draw the diagram of an alpha glucose molecule

Answer 15

Question 16

Draw the diagram of a beta glucose molecule

Answer 16

Question 17

describe the difference between the two isomers of alpha glucose and beta glucose

Answer 17

the position of the hydrogen and hydroxyl groups on the carbon 1 are inverted.

Question 18

when two glucose molecules join together in a condensation reaction what forms

Answer 18

maltose and water

Question 19

when a glucose molecule and a fructose molecule join together in a condensation reaction what is produced

Answer 19

sucrose and water

Question 20

when a glucose molecule and a galactose molecule join together in condensation reaction what is produced

Answer 20

lactose and water

Question 21

draw a diagram of a condensation reaction of 2 glucose molecules

Answer 21

Question 22

draw a diagram showing a hydrolysis reaction of 2 glucose molecules

Answer 22

Question 23

which monosaccharide is glycogen and starch made out of

Answer 23

alpha glucose

Question 24

which monosaccharide is cellulose made from

Answer 24

beta glucose

Question 25

draw a diagram of the polysaccharides starch and glycogen

Answer 25

Question 26

draw a diagram of the polysaccharide cellulose

Answer 26

Question 27

how is the structure of cellulose different from the structure of glycogen and starch

Answer 27

in the cellulose polymer the monomers face in **alternate directions** rather than all the same way like a starch polymer.

Question 28

explain why the structure of the polysaccharide chains of starch/ glycogen and cellulose are different

Answer 28

starch and glycogen are polymers of alpha glucose whereas cellulose is a polymer of beta glucose. in beta glucose the position of the hydrogen and hydroxyl groups on the carbon 1 are inverted

Question 29

explai why it is useful that starch is branched

Answer 29

- the branches provide **more ends** for enzymes to **hydrolyse** starch into **glucose** - so glucose is released **faster** in **respiration**

Question 30

how do the properties of starch relate to their function

Answer 30

coiled into a helix: compact so can fit a lot in a small space insoluble: doesn't effect osmosis large: cannot diffuse across cell membrane and out of cells highly branched: provides a larger surface area so can be more rapidly hydrolysed so glucose can be released more readily for respiration.

Question 31

how do the properties of glycogen relate to their function

Answer 31

coiled into a helix: compact so can fit a lot in a small space insoluble: doesn't effect osmosis large: cannot diffuse across cell membrane and out of cells highly branched: provides a larger surface area so can be more rapidly hydrolysed so glucose can be released more readily for respiration.

Question 32

describe the structure of cellulose

Answer 32

many **beta-glucose** molecules joined together, forming **long, straight and unbranched** chains of cellulose

Question 33

how do the properties of cellulose relate to its function

Answer 33

* long, straight and unbranched chains of beta glucose * linked together by many hydrogen bonds to form microfibrils * provide strength and rigidity to plant cell walls.

Question 34

summarise the differences and similarities between cellulose, starch and glycogen

Answer 34

Question 35

name the three tests for carbohydrates

Answer 35

benedicts test for reducing sugars, benedicts test for non-reducing sugar, iodine solution test for starch.

Question 36

describe the benedicts test for reducing sugars

Answer 36

* add benedicts solutions to sample and heat to 95 degrees * a colour change from blue to a brick red shows a positive result * if no change in colour then a non-reducing sugar is present

Question 37

suggest a way, other than comparing colour changes, in which different concentrations of reducing sugar could be estimated

Answer 37

- **filter** and **dry precipitate** in each sample - find the **mass** - the **higher the mass** of the precipitate the **more reducing sugar** is present

Question 38

describe the test for non-reducing sugar (sucrose)

Answer 38

- do benedicts test and if **stays blue** - boil a fresh sample with **acid** - **then** neutralise with **alkali ** - **heat** with benedicts solution at **95** degrees - if **non-reducing sugar **is present, there will be a **colour change** from blue to orange/ red

Question 39

describe the test for starch

Answer 39

* add iodine solution to sample * colour will change from orange to blue/black if starch is present

Question 40

what is the function of glycogen

Answer 40

the main glucose store in animals