Organic Chemistry

State the name of a family of compounds related in a certain way

Homologous series

Ethanol is a good solvent. Explain how ethanol could dissolve both polar and non-polar substances.

Ethanol has a polar -OH group that attracts polar molecules and a small hydrocarbon chain that attracts non-polar molecules.

State the function of yeasts in fermentation.

Function is that yeast is a micro-organism that releases the enzyme zymase that is used in the fermentation process.

State the colour of acidified potassium dichromate.

orange

Primary alcohols

Only one hydrocarbon chain (R) is attached to the carbon containing

the hydroxyl group

Secondary Alcohols

Two hydrocarbon chains (R and R’) are attached to the carbon

containing the hydroxyl group

Tertiary alcohols

Three hydrocarbon chains (R, R’ and R’’) are attached to the carbon

containing the hydroxyl group

what colour change indicates that a primary alcohol is present with acidified dichromate

orange to green

Name the organic technique used to obtain a more concentrated solution of ethanol.

Distillation

State one other condition, other than a warm temperature, that is required for fermentation to take place.

Anaerobic conditions

why does some stuff react with HBr

due to the C-C bond in the substance which allows addition reactions. Therefore it is likely that Her will add across the double bond the same as hydrogen

what is the carboxyl group

COOH

What are amines

Amines contain a carbon bonded to a basic nitrogen with a lone pair

Polarity of amines

Both N–C and N–H bonds in amino functional groups are polar. However, because nitrogen is less electronegative than oxygen, the magnitude of the partial charges in amines is considerably less than in functional groups which contain oxygen.

Why do amines act as bases

The lone pair on the nitrogen can accept H+ to form a protonated amine. ]

How do amines react in water

they form a protonated amine and hydroxide ion

How do amines react with acids

they react to form ionic salts which are water soluble

Why do many pharmaceutical drugs contain amino groups but are also large molecules with many non-polar components

these amine salts can form strong ion-dipole interactions with polar water molecules. Ion-dipole interactions are stronger than hydrogen bonds; hence, the drugs dissolve more easily in bodily fluids.

How are esters produced

An ester can be prepared by reacting a carboxylic acid with an alcohol in the presence of an acid catalyst. It is a condensation reaction, as a water molecule is produced.

What is the ester functional group

COO

How are esters named

alcohol component then carboxylate component

\

What type of reaction is involved in forming a polyester

This is a condensation reaction, as one water molecule is produced for each ester group.

What type of intermolecular forces do esters experience

dipole-dipole secondary interactions. This is because the carbon atom with a ∂+ charge is surrounded by other bulky atoms and cannot be accessed by ∂– atoms in other molecules.

are unsaturated hydrocarbon triglycerides more likely to be solid or liquid at room temperature

substance is likely to be a liquid at 25^oC because unsaturated substances have poorer packing and hence weaker secondary interactions (dispersion forces) caused by the greater distances between molecules. This leads to lower MPs.

systematic name for glycerol

propan-1,2,3-triol

what is a carbonyl group

C=O c double bonded to O

Monosaccharides are the simplest of the carbohydrates . name examples

Glucose and fructose

What are Disaccharides

 Disaccharides are made up of two monosaccharide molecules that have combined in a condensation reaction.

What are polysaccharides

The complex carbohydrates are condensation polymers of monosaccharides

What does complete hydrolysis of polysaccharides produce

Produces monosaccharides such as glucose while Partial hydrolysis may produce di- or trisaccharides.

Why does the cyclic form of glucose not contain aldehyde or ketone groups

The cyclic form does not contain the aldehyde or ketone groups because they are joined with an O-H on another part of the molecule to complete the ring. The sugars still act as aldehydes or ketones because there are enough straight chain molecules left.

where do saturated molecules come from

animals

where to unsaturated molecules come from

plants

How are carboxylic acids produced

Produced by oxidation of aldehydes or primary alcohols with excess acidified dichromate solution.

Carboxylic acids are weak acids therefore

Weak acids. Only ionize to a small extent to produce the carboxylate ion

Are potassium and sodium carboxylates soluble in water

Potassium and sodium carboxylates are soluble in water because of the strong ion – dipole bonds that form between the negatively charged carboxylate ion and the water molecules.

Are amines soluble in water

Some of the smaller primary amines are soluble in water because of the polar N-H bonds but as the molecule increase in size, their solubility decreases.

are salts of amines (protonated amines) soluble in water

The salts of amines (protonated amines) are soluble in water because of the ion – dipole attraction between the ions and water. This forms stronger bonds with water than the polar N-H groups found in amines.When insoluble amines react with acids they appear to dissolve because of the formation of the water soluble salts produced.

How are esters prepared

Esters are prepared by reacting an alcohol with a carboxylic acid in the presence of conc. sulfuric acid under reflux. This is a condensation reaction(water is produced). The reaction is slow and low yielding.

What is the reverse of preparing an ester

Hydrolyisis

products of alkaline hydrolysis of an ester

carboxylate anion and the alcohol.

systematic name of glycerol

propane-1,2,3-triol

what is it called if more than one C = C bond exists in a tryglericeride

polyunsaturated

what naturally occurring substances contain the amine link / peptide link

proteins

How to draw carboxylic acid in anionic form

get rid of H on OH and add - charge on O

how do u draw zwitterion

draw the molecule with both the cation and anion features/ acidic and alkaline conditions

what makes some proteins susceptible to oxidation

lone pair of electrons on nitrogen atom

name the reaction that converts sucrose into glucose and fructose

hydrolysis

what type of bonds does the less polar ester group form with itself

dipole-dipole interactions. they are weaker than hydrogen bonds

products of acidic amide hydrolysis

original carboxylic acid and protonated amine

products of alkaline amide hydrolysis

carboxylate anion and amine

products of acidic hydrolysis of an ester

original carboxylic acid and alcohol

products of alkaline hydrolysis of an ester

carboxylate anion and alcohol

what happens when an amine is protonated upon reaction with water (ONLY THING THAT HAPPENS TO AMINE)

Each N has + charge and gains a h

Type of reaction in which polysaccharides are converted into di or monosaccharides

hydrolysis

conditions needed for formation of ester

high temperature, concentrated catalyst eg sulphuric acid

what are isomers

isomers have the same molecular formula but a different structure formula

)  State an observation likely to be made during the reflux process making an ester

sweet fruity odour

why is the reflux process needed to make esters

                                  Esterification is a slow reaction

                                    Heating under reflux allows the reaction to occur at its

                                    boiling point (increasing the rate) without losing any of the

                                    reagents

(3)

why proteins are sensitive to changes in pH.

pH affects ionic bonding between NH₃⁺ and COO ^– side groups

causing disruption of the bonds that hold the structures in shape

what is primary structure

The sequence in which the amino acids are linked together

What is secondary structure

this refers to In aqueous solution, protein chains fold and coil in specific ways. The secondary structure is determined by the hydrogen bonding between non-adjacent amide functional groups.

What is tertiary structure

The folding that occurs between the twisted and folded chains (like a

coiled spring twisting in on itself) because of interactions between

distant amino acids.

Interactions may be due to:

 Covalent bonding (ie disulphide bridges)

 Hydrogen bonding between polar groups on a side chain

 Ionic bonds may form between -NH3

+ and –COO- groups

 Hydrophobic interactions where the non-polar groups exclude the polar regions

Tertiary structure gives proteins 3D shape

QUATERNARY STRUCTURE

The 3D arrangement of the packing together of a multi chain protein

Separate polypeptide chains can interact together to give a more

complex structure