Biological Molecules

Question 1

The variety of life of host past and present is extensive. However what is similar for all living things

Answer 1

The biochemical basis of life

Question 2

Monomers are the ———— units from which —————- molecules are made.

Answer 2

Smaller

Larger

Question 3

Give three examples of monomers

Answer 3

Monosaccharides
Amino acid
Nucleotides

Question 4

————— are molecules made from a ——- number of monomers ———- together.

Answer 4

Polymers
Large
Joined

Question 5

A condensation joins what together?
With the formation of what?
What molecule is eliminated?

Answer 5

Two molecules
A chemical bond
Water

Question 6

What does a hydrolysis reaction break?
Between what?
What molecule does it involve the use of?

Answer 6

A chemical bond
Between two molecules
Involves the use of a water molecule

Question 7

Three common monosaccharides from which larger carbohydrates are made

Answer 7

Glucose
Galactose
Fructose

Question 8

How are disaccharides formed

Answer 8

A condensation reaction between two monosaccharides with the formation of a glycosidic chemical bond and the elimination of a water molecule

Question 9

What is the chemical bond formed in a condensation reaction of two monosaccharides to form a disaccharide

Answer 9

GLYCOSIDIC bond

Question 10

How is the disaccharide maltose formed

Answer 10

Glucose + glucose arrow maltose + water

Question 11

Sucrose is formed how

Answer 11

Condensation reaction
Glucose + fructose
Glycosidic bond
Release of water

Question 12

Lactose is formed by

Answer 12

Condensation reaction
Glucose + galactose
Form glycosidic chemical bond
Release of water

Question 13

Name the two isomers of glucose

Answer 13

Alpha

Beta

Question 14

What does alpha glucose structure

Answer 14

H O

OH OH

Question 15

Structure of beta glucose

Answer 15

H O

OH H

Question 16

How are polysaccharide formed?
What reaction?
What molecule?

Answer 16

Condensation reaction between MANY glucose units

Glycosidic bond

Question 17

Name the three polysaccharides

Answer 17

Cellulose
Glycogen
Starch

Question 18

Glycogen and starch are made of what type of glucose

Answer 18

Alpha glucose

Question 19

Cellulose is formed by what type of glucose

Answer 19

Beta glucose

Question 20

What elements to carbohydrates contain?

In what ratio of H:O

Answer 20

C
H
O
2H:1O

Question 21

Carbohydrate can be classified into three groups. Name then

Answer 21

Monosaccharides
Disaccharide
Polysaccharides

Question 22

Mono and Di saccharides are —— and s——- molecules easy to t———- and ——— to taste

Answer 22

Small 
Soluble 
Transport 
W
Sweet

Question 23

What are monosaccharides mainly used in 2

Answer 23

Respiration (glucose) to provide energy

Growth in formation of larger molecules

Question 24

What is the general formulae for monosaccharides?
These are also called?
How are they different?

Answer 24

C6H12O6
Hexoses
They have different structures

Question 25

What are monosaccharides also called? | They give what result in the Benedicts test?

Answer 25

Reducing sugar | Brick Red

Question 26

Two ways the disaccharides can be HydroLysed into smaller monosaccharides

Answer 26

Boiling with acid (dilute HCL) | Heating with enzyme at OPTIMUM temperature

Question 27

The glycosidic bond is also called a what bond

Answer 27

1,4 (glycosidic bond between C 1 and 4)

Question 28

Which mono/disaccharide gives a NEGATIVE response to the bendicts tests

Answer 28

Sucrose

Question 29

Procedure of Benedict’s test | 4

Answer 29

Small amount of sample added to 2xm cube of Benedicts solution. Boiled in water bath for 5 mins Positive if turned brick red (produced by copper 1 oxide) Remind blue no reducing sugar

Question 30

The bendicts test can be used to compare the amount of sugar in different solutions. How would u carry this out

Answer 30

Same volume of BS Sams volume of sample Boiled for same amount of time The precipitate colour compression using Color meter

Question 31

Why does bendicts sultion turn red with reducing sugar

Answer 31

•Benedict’s reagent is an alkaline solution of copper(II) sulfate •Reducing sugars –OILRIG (of electrons) * Blue Benedict’s reagent is reduced * An insoluble red precipitate of copper(I) oxide is formed

Question 32

Test for non reducing sugar

Answer 32

Confirm that a reducing sugar is not present using the Benedict’s test. * Take another sample of the food to be tested. * Add 2cm3 of dilute hydrochloric acid in a test tube and place the test tube in a gently boiling water bath for 5 minutes. * This hydrolyses any dissacharide present into its constituent monosaccharides. * Add some sodium hydroxides solution to the test tube in order to neutralise the hydrochloric acid. * Re-test the resulting solution by heating it with 2cm3 of Benedict’s reagent in a gently boiling water bath for 5 minutes. * If a non-reducing sugar was present in the original sample, the Benedict’s reagent will now turn orange-brown.

Question 33

What two mixtures do we add for a non reducing bendicts test

Answer 33

Dilute acid Ed HCL | Dilute sodium hydroxide solution to neutralise

Question 34

How do the 3 polysaccharides differ

Answer 34

The number and arrangement of glucose

Question 35

Polysaccharides either function as 2

Answer 35

Storage or structural molecules

Question 36

What result do polysaccharides give in a bendicts test

Answer 36

Negative

Question 37

Non reducing sugars are non —— to taste. | Relatively ————— in water

Answer 37

Sweet | Insoluble

Question 38

Where is cellulose found? | What does it provide?

Answer 38

Cell wall of plants | Rigidity and shape to cell

Question 39

In a condensation of beta glucose to form a glycosidic chemical bond this reaction form a ——-, —————, ———. Why?

Answer 39

Long Straight Chain Every other beta glucose is inverted

Question 40

An OH group is called an

Answer 40

Hydroxyl group

Question 41

How is a microfibril formed in cellulose

Answer 41

``` The OH groups hydroxyl pRoJect from either side of the beta glucose chaIn to Form hydrogen bonds with HO groups On adjacent chains 3D structure known as microfibril ```

Question 42

Microfibril are grouped together into larger bundles known as

Answer 42

Microfibril

Question 43

How do microfibrils provide rigidity and full permeability

Answer 43

Macrofibrils of one layer are orientated in same direction Successive layer different direction Provide interwoven embedded matrix = rigidity The layers of macrofibrils have minute channels allow full permability of cellulose

Question 44

Starch is a ——— carbohydrate Where is it found? Where is it stored?

Answer 44

Storage Plants Stored in starch grains amyloplasts in the cytoplasm

Question 45

Why is starch ideally suited to its function as a storage compound 2

Answer 45

Insoluble so osmotically inactive so does not draw water into cell by osmosis which could lead to cell damage Helical shape forming compact store

Question 46

Starch is hydrolysed by what enzyme? | Into what disaccharide?

Answer 46

Amylase | Maltose

Question 47

Test for starch

Answer 47

Iodine test Add 2 drops of iodine solution = black / blue preset Remains yellow/ orange not present

Question 48

What type of carbohydrate is glycogen? Where is it found? Where is it stored?

Answer 48

Storage Animal cells Cytoplasm Usually in large amounts in liver and muscle tissues

Question 49

How is glycogen different to starch? 1 | How is the same (function suitability)

Answer 49

Has more branches (free ends) so can be hydrolysed rapidly to release glucose for respiration. Insoluble and osmotically inactive