biological molecules BAILEY

Question 1

define monomers

Answer 1

small molecular unit

Question 2

define polymerisation

Answer 2

process of forming a polymer from many monomers

Question 3

define a condensation reaction

Answer 3

when a monomer is joined to another monomer forming a chemical bond and a molecule of water

Question 4

define hydrolysis reaction

Answer 4

polymers can be broken down into monomers by using water to break chemical bonds

Question 5

name one monosaccharide

Answer 5

glucose

Question 6

name 3 polysaccharide

Answer 6

glycogen
starch
cellulose

Question 7

name the polymer made out of amino acids

Answer 7

polypeptides
(proteins)

Question 8

name one type of proteins

Answer 8

enzymes

Question 9

name a polynucleotide

Answer 9

DNA
RNA

Question 10

write a method of how to test for reducing sugars
(all monosaccharides all disaccharides)

Answer 10

1. equal volumes of sample and Benedict’s solution
2. HEAT gently for 5 mins

if the sample stays blue this is the negative result and means there no reducing sugars in the sample

sample could change colour
RED (strongest concentration of sugar)
ORANGE
YELLOW
GREEN

Question 11

Name one issue with using Benedict’s to test for reducing sugars

Answer 11

it’s semi quantitative
colours can be subjective

Question 12

What is a more accurate way to measure the amount of reducing sugar

Answer 12

use a colourimeter to measure how much light passes through the sample

Question 13

list 2 positives of using a colourimeter

Answer 13

it is quantitative
standardises

Question 14

when testing how much sugar there is in a precipitate after drying and filtering it
What does the mass mean

Answer 14

more mass = more reducing sugars

Question 15

what elements are carbohydrates made up out of

Answer 15

C H O

Question 16

in a condensation reaction with 2 monosaccharides what is formed

Answer 16

disaccharide

Question 17

name one disaccharide

Answer 17

sucrose
maltose
lactose

Question 18

what is the general formula for monosaccharides

Answer 18

CnH2nOn

Question 19

name 3 monosaccharides

Answer 19

glucose
galactose
fructose

Question 20

name 2 reducing sugars

Answer 20

maltose
lactose

Question 21

name the 2 isomers of glucose

Answer 21

beta glucose
alpha glucose

Question 22

state the formula for hexose

Answer 22

C6H12O6

Question 23

what type of sugars are all made out of alpha glucose

Answer 23

all disaccharides are made out of alpha glucose

Question 24

give 2 properties of glucose, galactose, fructose

Answer 24

soluble
sweet tasting

Question 25

describe how disaccharides are formed

Answer 25

disaccharides are 2 monosaccharides joined together by a condensation reaction (forming a new glyosidic bond and a water molecule is released)

Question 26

when the react 2 alpha glucose molecules what is formed as the products

Answer 26

alpha glucose + alpha glucose = maltose + water

Question 27

name the reactants to form sucrose + water

Answer 27

glucose + fructose

Question 28

name the reactants to form lactose + water

Answer 28

galactose + glucose

Question 29

name the reactants to form maltose + water

Answer 29

glucose + glucose

Question 30

give the method to test for non reducing sugars

Answer 30

1. heat if the sample stays blue then no reducing sugars are present 2. add sample and HCl (hydrolyses the glyosidic bond producing a reducing sugar) and boil for 5 mins 3. add NaHO3 to neutralise the sample 4. add Benedicts reagent and heat 5. no non reducing sugars in sample will stay blue as this is a negative result 6. the colour change will be green, orange, red and then a non reducing sugar is present

Question 31

How are polysaccharides created

Answer 31

Polysaccharides are created by condensation reactions between many glucose monomers

Question 32

What are the monomers of starch

Answer 32

Alpha glucose

Question 33

In starch what are the bonds between monomers

Answer 33

1-6 and 1-4 glycosidic bonds in amlopectin

Question 34

Where is starch located

Answer 34

In starch grains in plant cells

Question 35

What is the function of starch

Answer 35

Insoluble store of glucose

Question 36

What is the structure of starch

Answer 36

2 polymers Amylose- unbranched helix Amylopectin- a branched molecule

Question 37

Explain how the structure of starch leads to its function

Answer 37

Helix can compact to fit a lot of glucose into a small space Branched surface increases the surface area for rapid hydrolysis back to glucose

Question 38

What are the monomers of cellulose

Answer 38

Beta glucose

Question 39

What are the bonds between the monomers in cellulose

Answer 39

1-4 glycosidic bonds

Question 40

What is the function of cellulose

Answer 40

Structural strength to cell wall

Question 41

Where is cellulose located

Answer 41

Cell wall of plant cells

Question 42

Describe the structure of cellulose

Answer 42

Long straight chains of 1-4 glycosidic bond are held together in parallel by many hydrogen bonds (fibrils)

Question 43

Explain how the structure of cellulose leads to its function

Answer 43

Many hydrogen bond provide collective strength

Question 44

What are the monomers of glycogen

Answer 44

Alpha glucose

Question 45

What are the bonds between monomers in glycogen

Answer 45

1-4 and 1-6 glycosidic bonds

Question 46

What is the function of glycogen

Answer 46

Insoluble store of glucose

Question 47

Where is glycogen located

Answer 47

Muscle and liver cells in animals

Question 48

What is the structure of glycogen

Answer 48

A highly branched molecule (has more 1-6 glycosidic bonds)

Question 49

Explain how the structure of glycogen leads to its function

Answer 49

Branched structure increases the surface area for rapid hydrolysis (faster hydrolysis back to glucose) And then glucose provides the respiratory substrate for energy release Insoluble so does not affect water potential Helix is compact

Question 50

Describe 2 differences between the structure of cellulose molecule and a glycogen molecule

Answer 50

Glycogen is a highly branched molecule but cellulose is in long straight chains Cellulose is made out beta glucose and glycogen is made out of alpha glucose Glycogen has 1-4 glycosidic bonds and 1-6 glycosidic bonds but cellulose only has 1-4 glycosidic bonds

Question 51

Describe and explain 2 features of starch that makes it a good storage molecule

Answer 51

- helix can compact to fit a lot of glucose into a small space - branched surface increases the surface area for rapid hydrolysis of starch into glucose

Question 52

list the 2 types of lipids

Answer 52

Phospholipids Triglyceride

Question 53

List the 5 roles of lipids

Answer 53

- phospholipids form cell membranes (Flexible and transfer soluble substances) - energy source (When oxidised release 2x the energy of carbohydrates) - protection (around organs) - waxy cuticle/oils from sebaceous glands in the skin (Waterproofing) - insulation (warmth, myelin sheath around neurona allows electrical impulses to be transmitted quickly)

Question 54

list 3 characteristics of lipids

Answer 54

- C H O but less than in carbohydrates - insoluble in water so doesn't affect water potential - soluble in organic solvents (alcohol)