M2 C3 Biological molecules

Question 1

what are the 4 most abundant elements present in biological molecules and how many bonds can they have

Answer 1

hydrogen- 1 oxygen- 2 nitrogen- 3 carbon- 4

Question 2

name 5 important properties of water and relate them to its structure

Answer 2

adhesion- the attraction between water molecules & surface molecules

cohesion- the attraction between water molecules caused by hydrogen bonds, leads to surface tension

good solvent- dissolves most substance

coolant- high specific heat capacity & latent heat

Question 3

explain what a monomer is

Answer 3

a single unit

Question 4

how do monomers form polymers

Answer 4

create glycosidic bonds and lose water (condensation reaction) with other monomers

Question 5

what is a monosaccharide

Answer 5

a single unit of sugar

Question 6

what is a disaccharide

Answer 6

two sugar units joined to

Question 7

what is a polysaccharide

Answer 7

many sugars joined together

Question 8

how are bonds formed in carbohydrates

Answer 8

condensation reactions

Question 9

describe the structure of starch and how relates to its function

Answer 9

its made from
- amylose: made from 1,4 glycocidic bonds and forms a single coilled strand of alpha glucose which is easily broken down to use for energy

• amylopectin: made from 1,4 and 1,6 glycocidic bonds .: branched. insoluble so it doesnt effect water potential amd is good for storage as it is compact due to the branches

Question 10

describe the structure of glycogen and how relates to its function

Answer 10

very branched due to 1,4 and 1,6 glycocidic bond

Question 11

describe the structure of cellulose and how relates to its function

Answer 11

straight due to 1,4 glycosidic bonds and alternating beta glucose molecules, for structural purpose in plant cells

Question 12

how is a calibration curve used to find unknown concentrations

Answer 12

Where it crosses the x axis

Question 13

what are the main principals of colorimetry

Answer 13

pfegbthy

Question 14

describe the structure of triglycerides

Answer 14

• made up of one glycerol and 3 fatty acids
• glycerol is an alcohol and has 3 carbons & 3 -OH groups
• fatty acids have a carboxyl group (-COOH) on one end, attached to a hydrocarbon tail
• fatty acids are acids as they ionise to form H+ and -COO~

Question 15

describe the structure of phospholipids

Answer 15

same as triglycerides but one of the fatty acids is replaced by a phosphate group

Question 16

name and describe the bond in lipids

Answer 16

ester

Question 17

what is the difference between saturated and unsaturated fats

Answer 17

Saturated- single bonds, solid

Unsaturated- double bonds, liquid

Question 18

test for proteins

Answer 18

Add beiurets solution

Question 19

test for lipids

Answer 19

Emulsification, and water and mix should become cloudy

Question 20

test for reducing sugars

Answer 20

benedicts solution and heat,

Question 21

test for non-reducing sugars

Answer 21

Add benedicts solution should be negative result then add HCL and heat (hydrolysis) then neutralise the acid with NaOH before adding benedicts solution

Question 22

test for starch

Answer 22

Iodine

Question 23

principals of chromatography

Answer 23

phrybgs

Question 24

Rf values

Answer 24

psbrg

Question 25

Primary structure of proteins & amino acids

Answer 25

Primary - sequence of amino acids - peptide bonds

Question 26

what is the difference between globular and fibrous proteins

Answer 26

Fibrous proteins are relatively long, thin and insoluble in water whereas globular proteins are relatively spherical and soluble in water

Question 27

name 4 important ions and their role in living organisms

Answer 27

Ca: muscle contractions Na & K: nerve impulse transmission K: open stomata

Question 28

secondary structure of proteins & amino acids

Answer 28

- forms a helix shape or beta sheet chains that lie parallel to each other are joined by H bonds - bonds involved: peptide, hydrogen, alpha hydrogen bonds between O & H

Question 29

tertiary structure of proteins & amino acids

Answer 29

This is the folding of the protein into its shape. Coiling & folding brings R groups close to one another H/ionic/disulphide bridges bonds between R groups hold twists/loops in place

Question 30

quaternary structure of proteins & amino acids

Answer 30

- association of two or more individual proteins - R group interactions between submits - hydrophobic and hydrophilic interactions

Question 31

Similarities between fibrous and globular

Answer 31

They are all polypeptides encoded by DNA consist of any combination of the 20 amino acids

Question 32

ROLES OF LIPIDS TRIGLYCERIDES Long term energy store

Answer 32

They are insoluble in water :. can be stored w/o affecting the wa

Question 33

describe the structure and properties of triglycerides

Answer 33

jfjf

Question 34

how are phospholipids formed

Answer 34

- condensation reaction between an OH group on a phosphoric acid molecule and one of the three -OH groups on the glycerol forms an ester bond

Question 35

describe the structure and properties of phospholipids

Answer 35

dds