Core Concepts: Biological Molecules

Question 1

What are the 4 key elements that make up biological molecules and are essential for living

Answer 1

Oxygen
Carbon
Hydrogen
Nitrogen

Question 2

What are four macronutrient inorganic ions

Answer 2

Magnesium
Iron
Phosphate
Calcium

Question 3

What is the importance of Magnesium

Answer 3

It’s a part of chlorophyll, without it chlorophyll can’t be made so the leaves turn yellow

Question 4

Whats the importance of Iorn

Answer 4

Its part of haemoglobin, lack of iron in the human diet can lead to anaemia

Question 5

What is the importance of Phosphate

Answer 5

Used for making nucleic acids such as DNA, RNA and ATP. Its a part of phospholipids, found in plasma membranes.

Question 6

What is the importance of calcium

Answer 6

Its a structural component for bones and teeth.

Question 7

What does inorganic mean

Based on this what would organic mean

Answer 7

Compounds that do not contain carbon bonded to hydrogen like water or carbon dioxide

Compounds that consist of carbon bonded to hydrogen.

Question 8

What is a Micronutrient

Answer 8

Inorganic nutrients needed in minute traces e.g copper and zinc

Question 9

What is a Macronutrient

Answer 9

Inorganic ions needed in small amounts e.g phosphate, calcium, magnesium and iron.

Question 10

What is polymerisation

Answer 10

The linking together of identical monomers to form larger molecules called polymers.

Question 11

State one way polymerisation can occur and what is eliminated in this reaction.

Answer 11

Condensation reaction, in this reaction water is eliminated

Question 12

State one way a polymer can be broken down and what is added.

Answer 12

Hydrolysis reaction, in this reaction water is added.

Question 13

What elements to carbohydrates contain

Answer 13

Carbon Oxygen and Hydrogen

Question 14

What are the two main functions of carbohydrates

Answer 14

• Storage and release of Energy
• Cellular structures (like cellulose cell walls in plants)

Question 15

What are the three types of carbohydrate.

Answer 15

Monosaccharides
Disaccharides
Polysaccharides

Question 16

What are monosaccharides

Answer 16

These are monomers of much larger and complex carbohydrates

Question 17

What are disaccharides and what bond is involved

Answer 17

These are two monosaccharides combined together by glycosidic bonds.

Question 18

What are polysaccharides

Answer 18

These are Large carbohydrates made up of monosaccharides joined together by glycosidic bonds.

Question 19

What is the general formula for carbohydrates

Answer 19

Cn(H2O)n

Question 20

If a monosaccharide has 3,5 and 6 carbon atoms what sugar is it (3)

Answer 20

3 = Triose
5 = Pentose
6 = Hexose

Question 21

What is an isomer

Answer 21

An isomer is when there is the same amount of molecules but different arrangement of their atoms

Question 22

What is the difference between alpha-glucose and beta-glucose. And what acronym can I use to remember this

Answer 22

They are isomers. the arrangement of OH and H bonded to the carbon 1 is different In both glucoses. ABBA (Alpha Below Beta Above) Meaning for alpha the OH is below the Carbon 1 but for beta the OH is above Carbon 1.

Question 23

Whats a useful property of monosaccharides

Answer 23

They are small therefore they are soluble in water and can easily dissolve inside the cells and are easily transported in the blood stream for animals.

Question 24

Name two hexose sugars that are also isomers.

Answer 24

Fructose and galactose

Question 25

Name the three disaccharides

Answer 25

Maltose Sucrose Lactose

Question 26

What two monosaccharides is Maltose, Sucrose and Lactose made up of

Answer 26

Maltose = a-glucose + a-glucose Sucrose = glucose + fructose Lactose = glucose + galactose

Question 27

Where is Maltose found and what is it used for

Answer 27

Maltose is found inside seeds and is a important source of glucose during germination

Question 28

What is Sucrose used for

Answer 28

Transported through the phloem of all plants

Question 29

What is Lactose used for

Answer 29

This is found in mammalian milk and is an important source of energy for their young.

Question 30

Explain why a bond may be called 1-4 glycosidic bond

Answer 30

This is because the bond occurs between carbon 1 and carbon 4 of the monosaccharide

Question 31

Draw a condensation reaction of maltose between two alpha-glucose monomers.

Answer 31

Refer to page 9 of Biological molecules booklet.

Question 32

What two main functions can a polysaccharide have

Answer 32

* Storage * Structural

Question 33

What three properties do storage polysaccharides such as glycogen and starch have

Answer 33

Insoluble - don't effect osmosis Compact - so can be stored in a small place in the cell Easily be hydrolysed - to release the glucose for respiration

Question 34

Give 4 examples of polysaccharides, which of them are structural or storage and which of them are animal or plant.

Answer 34

Starch - storage - plant Glycogen - storage - animals Cellulose - structural - plants Chitin - structural - animals

Question 35

What are the two types of starch

Answer 35

Amylose and amylopectin

Question 36

What type of glucose is amylose starch made up of, what type of structure does it have and what bonds does it have

Answer 36

Amylose Starch is made of alpha glucose monomers - straight chained helix structure - alpha 1-4 glycosidic bonds

Question 37

What type of glucose is amylopectin starch made up of, what type of structure does it have and what bonds does it have

Answer 37

Amylopectin Starch is made of alpha glucose monomers - branched polymer - alpha 1-4 and 1-6 glycosidic bonds

Question 38

What is glycogen found (2)

Answer 38

Liver and muscle cells

Question 39

What type of glucose is glycogen made up of, what type of structure does it have and what bonds does it have

Answer 39

glycogen is made up of alpha glucose monomers - highly branched - alpha 1-4 and 1-6 glycosidic bonds

Question 40

Why does glycogen being highly branched a good thing

Answer 40

It allows the quick release of glucose from the ends of branches to be used in respiration

Question 41

What type of monomers is cellulose made up of, what type of structure does it have and what bonds does it have

Answer 41

cellulose is made up of beta monomers - straight chained - beta 1-4 and 1-6 glycosidic bonds

Question 42

Why is cellulose useful in plants

Answer 42

It is very useful in plant cell walls as it gives the cell wall rigidity, this is because cellulose makes the cell wall inelastic and have high tensile strength to keep the cell from bursting

Question 43

Explain the structure of cellulose and why its strong in plant cells

Answer 43

Beta monomers are joined together by glycosidic bonds, with each beta glucose molecule rotated 180° to each other. This forms straight chains that can be joined to other straight chains via hydrogen bonds in the OH group. Many straight chains joined together can make a strong microfibril which can form a strong cellulose bundle.

Question 44

What is the structure of chitin similar to and what differs

Answer 44

Chitin is similar to cellulose however some of the OH bonds are replaced with nitrogen

Question 45

What are the three main properties of chitin

Answer 45

Lightweight Waterproof very strong

Question 46

what are the two types of lipids

Answer 46

triglycerides and phospholipids

Question 47

What are the two main components that make up triglycerides

Answer 47

Glycerol and fatty acids