Topic 1A- Biological molecules

Question 1

how do we know that we all desended from a common ansestor

Answer 1

we all have the same biochemisty, all contain the ame group og carbon-based compounds that interact in a similar way

Question 2

what is a monomer

Answer 2

make up polymers

e.g monosaccharide

Question 3

what is a polymer

Answer 3

chain of monomers

Question 4

how do you make a polymer

Answer 4

condensation reactions, removal of a molecule of water to monomers

Question 5

how do you break down polymers

Answer 5

hydrolysis reactions, the addition of a water molecules

Question 6

what are the monosaccharides

Answer 6

glucose, fructose and galactose

Question 7

what type not sugar is glucose

Answer 7

hexose

Question 8

what are alpha and beta types of

Answer 8

glucose

Question 9

what are isomers

Answer 9

molecules either the same molecular formula as each other but the atoms are connected differently

Question 9

what is the difference between alpha and beta glucose

Answer 9

the right H2O group are reversed, H is at the top for A glucose

Question 10

what forms when two monosaccharides join together

Answer 10

disaccharide

Question 11

how are monosaccharides formed and what bond is between them

Answer 11

condensation reaction and a glycosidic bond

Question 12

what are sugars classified as

Answer 12

reducing or non-reducing

Question 13

how do you test for reducing sugars

Answer 13

add Benedict’s reagent to a sample and then heat up in a hot water bath that’s been brought to the boil

Question 13

what is a positive result for reducing sugars

Answer 13

green/yellow/orange/brick red, any solids will suspend in the solution

Question 14

what alters the colour of the solution after being tested

Answer 14

the concentration

Question 15

how can you compare amounts of reducing sugars more accurately

Answer 15

filter the solution and weigh the precipitate, or remove precipitate and use a colorimeter to measure the absorbence of the reaming benedict’s reagent

Question 16

test for non-reducing sugars

Answer 16

add dilute HCl acid to solution and heat in a hot water bath. neutralise the solution by adding sodium hydrogencarbonate. then heat with benedict’s reagent

Question 17

positive result for non-reducing sugars

Answer 17

green/yellow/orange/brick red

Question 18

what are the three polysaccharides

Answer 18

starch, glycogen and cellulose

Question 19

ow do plants store excess glucose

Answer 19

starch

Question 20

what is starch a mixture of

Answer 20

amylose and amylopectin

Question 21

what is amylose

Answer 21

long unbranched chain of alpha glucose

Question 22

what shape do the glycosidic bonds form for amylose

Answer 22

coiled/helix

Question 23

why is a helix shape for amylose useful

Answer 23

better for storage and can fit into small places

Question 24

what shape is amylopectin

Answer 24

long, branched chain of alpha glucose

Question 25

why is the branched shape of amylopectin helpful

Answer 25

the enzyme can easily break the bonds quickly

Question 26

does starch affect water potential?

Answer 26

no, its insoluble

Question 27

how do aimals store glucose

Answer 27

gycogen

Question 28

what is glycogen a polysaccharide of

Answer 28

alpha glucose

Question 29

does glycogen have more branches than amylopectin

Answer 29

yes, many more

Question 30

why is the branched molecule needed for animals to release energy quicker

Answer 30

they need to maintain a body heat, therefore more branches mean more energy released quicker

Question 31

what is cellulose made from

Answer 31

beta glucose

Question 32

what shape does cellulose make

Answer 32

straight chains

Question 33

what are the cellulose chains joined by

Answer 33

hydrogen bonds

Question 34

what are joined chains of cellulose called

Answer 34

microfibrils

Question 35

what does strong cellulose fibres provide

Answer 35

provides support

Question 36

what test do you do for the presence of starch in a solution

Answer 36

iodine test

Question 37

what is the iodine test

Answer 37

add iodine dissolved in potassium iodide to the solution

Question 38

positive result of iodine test

Answer 38

sample changes from browny-orange colour to a dark blue colour