Module 2: Section 2 - Biological Molecules

Question 1

What does water being di polar result in

Answer 1

Attracts positively and negatively charged ions towards it

Question 2

How do hydrogen bonds form

Answer 2

Hydrogen is slightly positively charged and oxygen slightly negatively charged so these opposite charges attract to each-other forming hydrogenbonds

Question 3

What does hydrophilic mean

Answer 3

It attracts water (water loving)

Question 4

Do charges / polar molecules dissolve readily in water and if they do what are they called

Answer 4

Yes and are called hydrophilic

Question 5

Do charges/ non polar molecules dissolve readily in water and if not what are they called

Answer 5

No and are called hydrophobic

Question 6

What does hydrophobic mean

Answer 6

It repels water (water hating)

Question 7

How can water resist changes in temperature

Answer 7

Hydrogen bonds between water molecules can absorb a lot of energy. This means they have a high specific heat capacity so it doesn’t change temperature very easily and remains at constant temperature

Question 8

Why is water having a high specific heat capacity good for organisms

Answer 8

The constant temperature is good for organisms because it means water doesn’t experience rapid temperature changes so it’s a good habitat for them. And water inside organisms is stable which helps them maintain a constant internal body temperature

Question 9

Why is water having a high specific heat capacity good for organisms

Answer 9

The constant temperature is good for organisms because it means water doesn’t experience rapid temperature changes so it’s a good habitat for them. And water inside organisms is stable which helps them maintain a constant internal body temperature

Question 10

What is cohesion

Answer 10

It’s the tendency for molecules within a substance to stick together

Question 11

Why are water molecules very cohesive

Answer 11

They are polar hydrogen bonds so can stick together

Question 12

What does waters strong cohesion do

Answer 12

Helps water to flow which is useful for transporting substances
Gives the water a high surface tension, allowing small organisms to walk/ move on the surface of things like a pond

Question 13

Is waters solid or liquid form more dense

Answer 13

Liquid

Question 14

How are water’s density and freezing properties beneficial for organisms

Answer 14

Ice floats on water and insulates the water below it reducing the chances of organisms completely freezing and increasing chances of life

Question 15

What are monomers

Answer 15

Small, identical or similar molecules,that can be joined together to make large molecules called polymers

Question 16

What are polymers

Answer 16

Large molecules which are formed by joining many identical or very similar monomers together

Question 17

What is a hexose sugar

Answer 17

A monosaccharide which has six carbon atoms in each molecule

Question 18

What are the types of glucose

Answer 18

Alpha and beta

Question 19

What is an isomer

Answer 19

Same molecular but the atoms are connected in a different way

Question 20

Is glucose a hexose or Pentose sugar

Answer 20

Hexose

Question 21

What is the difference between alpha and beta glucose

Answer 21

Alpha have a H on top and OH on the bottom and beta has a OH on top and H on bottom

Question 22

What bonds are carbohydrates joined by

Answer 22

Glycosidic bonds

Question 23

What bonds are proteins joined by

Answer 23

Peptide bonds

Question 24

What bonds are lipids joined by

Answer 24

Ester bonds

Question 25

What elements do carbohydrates contain

Answer 25

Carbon, hydrogen and oxygen

Question 26

How are disaccharides formed

Answer 26

Two monosaccharides are joined by a glycosidic bond (condensation reaction) and a water molecule is released

Question 27

What is glucose +glucose

Answer 27

Maltrose

Question 28

What is glucose and fructose

Answer 28

Sucrose

Question 29

What is glucose and galactose

Answer 29

Lactose

Question 30

What is cellulose structure

Answer 30

-Polymer of beta glucose -Made of long unbranched chains of beta glucose - 2nd glucose is inverted so cellulose molecule is straight rather than curved - cellulose chains linked together by hydrogen bonds to form cellulose micro fibrils and as these fibres are so strong it supports the cell

Question 31

What is starch a mixture of

Answer 31

Two polysaccharides of alpha glucose amylose and amylopectin

Question 32

What is amylose structure

Answer 32

-Long - unbranched chain of alpha glucose - 1-4 glycosidic bonds - coiled, cylinder like structure due to the angle of glycosidic bonds

Question 33

Amylopectin structure

Answer 33

-Long - branched chain of alpha glucose - side branches -1-6 glycosidic bonds -compact

Question 34

Glycogen structure

Answer 34

-long branched chain -1-4 and 1-6 glycosidic bonds - side branches -compact

Question 35

Why are compact branches good

Answer 35

Good for Energy storage

Question 36

What is glycogens function

Answer 36

Energy storage in animals, bacteria and fungi

Question 37

What are triglycerides soluble in and insoluble in

Answer 37

Soluble in alcohol Insoluble in water as not polar

Question 38

How are triglycerides formed

Answer 38

1 glycerol esterified with three fatty acid

Question 39

Triglycerides function

Answer 39

Storing energy

Question 40

What are phospholipids structures

Answer 40

-1 glycerol esterified with two fatty acid groups and 1 phosphate group - phosphate head is hydrophilic and polar(water soluble) and the tails are non polar and hydrophobic

Question 41

What happens when phospholipids are mixed with water

Answer 41

Form droplet spheres with the hydrophilic heads facing the water and the hydrophobic tails facing eachother

Question 42

What is amino acids general structure

Answer 42

-central carbon -amino group -carboxyl group -hydrogen atom -an R group

Question 43

How are polypeptides formed

Answer 43

Condensation reactions between the amine group of one amino acid and the carboxyl group of another

Question 44

What are the 4 levels of the protein structure

Answer 44

Primary structure, secondary structure,tertiary structure and the quaternary

Question 45

What is the primary structure

Answer 45

The unique sequence of amino acids in the polypeptide chain

Question 46

What are the bonds that hold the secondary structure of proteins together

Answer 46

Hydrogen bonds which cause the protein to fold into specific structures

Question 47

What are two secondary structures of proteins

Answer 47

Alpha helix Beta pleated sheet

Question 48

Why are the secondary structure of proteins stable

Answer 48

Many hydrogen bonds

Question 49

How does the secondary structure form

Answer 49

Primary polypeptide chain folds to form a secondary structure ( result of protein folding)

Question 50

How does the tertiary structure form

Answer 50

Further foldings in the secondary structure

Question 51

What are the bonds in the tertiary structure

Answer 51

Hydrogen bonds-which are weak Ionic bonds- which are strong Sulphur bridges -which are strong

Question 52

How is the quaternary structure formed

Answer 52

The interaction between many polypeptides

Question 53

Examples on quaternary structure of proteins

Answer 53

-collagen(protein in skin)has 3 polypeptide chains -haemoglobin( globular proteins 4 polypeptide chains) -insulin(2 polypeptide chains held together by disulphide bonds)

Question 54

what is meant by a conjugated protein

Answer 54

1. contains non-protein groups 2. has prosthetic group 3. (prosthetic group) is , iron / Fe , ion 4. (prosthetic group) is attached by , covalent bonds / ionic interactions / hydrogen bonds

Question 55

what are fibrous proteins properties

Answer 55

-insoluble in water -strong -stable (unreactive)structure -polypeptide chains form long twisted strands -form hydrogen bonds with adjacent chains

Question 56

what are globular proteins properties

Answer 56

-unstable (reactive) structures -soluble -Hydrophobic R group on the inside and hydrophilic on the outside -Polypeptide chains roll up into spherical shape

Question 57

what are 3 roles of lipids

Answer 57

-energy storage -thermal insulation -protection

Question 58

What are the examples of globular proteins and what do they do

Answer 58

- Haemoglobin has 4 polypeptide chains and a prosthetic group called a haem, it carries oxygen around the red blood cells - insulin is a hormone secreted in the pancreases and consists of 2 polypeptide chains -amylase is an enzyme that catalyses the breakdown of starch

Question 59

what are the examples of fibrous proteins and what do they do

Answer 59

-collagen is found in animal connective tissues e.g skin and is very strong -keratin is found in skin hair nails.it can be flexible or tough -elastin- found in elastic connective tissues such as skin . As its elastic it allows the tissue to return to its original shape

Question 60

What are the elements in Carbohydrates

Answer 60

Carbon, Hydrogen and oxygen

Question 61

What are the elements in lipids

Answer 61

Carbon, hydrogen and oxygen

Question 62

What are the elements in proteins

Answer 62

Carbon, hydrogen, oxygen, nitrogen and sulphur

Question 63

What are the elements in nucleic acids

Answer 63

Carbon, hydrogen, oxygen, nitrogen and phosphorus