Download presentation
Presentation is loading. Please wait.
Published byJennifer Winne Modified over 10 years ago
2
Unit 2 Carbon compounds
3
Menu To work through a topic click on the title. Fuels Nomenclature and structural formula Reactions of carbon compounds Plastics and synthetic fibres Natural products Click here to End.
4
Fuels
5
A fuel is a chemical which burns, releasing energy. Combustion is another word for burning, the reaction of a substance with oxygen, in which energy is given out.
6
Hydrocarbons The chemical compounds which are found in oil and natural gas are mainly hydrocarbons. A hydrocarbon is a compound which contains hydrogen and carbon only.
7
Hydrocarbons burn in a plentiful supply of air to produce carbon dioxide and water. The test for carbon dioxide is that it turns lime water milky.
8
Burning candle Lime water (turns cloudy) Anhydrous copper sulphate (turns blue) To pump
9
Incomplete Combustion When fuels burn in a limited supply of air then incomplete combustion takes place and the poisonous gas, carbon monoxide (CO) is produced. Increasing the amount of air used to burn fuel improves efficiency and decreases pollution.
10
Other products of combustion Fossil fuels contain sulphur which produces sulphur dioxide when the fuel is burned. The oil industry tries to remove this sulphur from the fuels before selling them.
11
Nitrogen does not react well because of its strong bonds. Air +- High Voltage spark If there is a high temperature the nitrogen and oxygen will combine to make nitrogen oxides. The experiment opposite shows how a high voltage spark, like one provided by the spark plug or lightning will do the same.
12
Nitrogen does not react well because of its strong bonds. If there is a high temperature the nitrogen and oxygen will combine to make nitrogen oxides. The experiment opposite shows how a high voltage spark, like one provided by the spark plug or lightning will do the same. Air +- High Voltage spark Brown gas
13
Atmospheric Pollution The sulphur and nitrogen oxides produced can dissolve in water, making acid rain. Unburnt hydrocarbons escaping from car exhausts can help cause the destruction of the ozone layer.
14
Reducing Pollution Air pollution caused by burning hydrocarbons can be reduced by: using a special exhaust system – a catalytic converter, in which metal catalysts (platinum or rhodium) will convert pollutants into harmless gases. altering the fuel to air ratio.
15
Pollution Soot particles produced by the incomplete combustion of diesel are harmful.
16
Oil Crude oil is a mixture of chemical compounds (mainly hydrocarbons) which can be to split it into fractions. Oil can be separated into fractions by the process of fractional distillation.
17
Oil A fraction is a group of chemical compounds, all of which boil within the same temperature range.
18
Fractional Distillation of Oil Heated oil from furnace gases petrol (gasoline) naphtha paraffin (kerosine) residue diesel (petrol) (gaseous fuel) (chemicals) (aircraft fuel) (fuel for lorries etc.) (wax, tar)
19
Oil Fractions NameCarbon atoms per molecule Uses Gases1 to 4Fuel Petrol 4 to 9Fuel for cars Naphtha8 to 14Chemicals Paraffin10 to 16Aircraft fuel Diesel15 to 20Lorry fuel ResidueMore than 20Lubricating oil, tar, wax etc.
20
Viscosity is a measure of the thickness of a liquid. Flammability is a measure of easily the liquid catches fire.
21
As the boiling point of a fraction increases then: it will not evaporate as easily. it will be less flammable it will be more viscous (thicker).
22
Moving through the fractions from gases to the residue The molecules present in the fraction are longer and heavier They will find it more difficult to become a gas i.e. they will be less easy to evaporate.
23
Moving up the fractions from gases to the residue Since combustion involves the reaction of gas molecules with oxygen flammability will decrease. Increased molecular lengths mean that molecules become more "tangled up", so the liquid will become thicker (more viscous).
24
Fuels Click here to repeat Fuels Click here to return to the Menu Click here to End.
25
Nomenclature & Structural formula
26
Nomenclature Nomenclature means the way chemical compounds are given names. These names are produced by a special system.
27
Naming hydrocarbons All hydrocarbons belong to “families” called homologous series. A homologous series is a set of compounds with the same general formula and similar chemical properties.
28
Homologous Series General formula Name alkanesC n H 2n+2 ….ane alkenesC n H 2n ….ene cycloalkanesC n H 2n cyclo….ane
29
The other part of the name tells us how many carbon atoms are present.
30
Number of C atoms nameNumber of C atoms name 1meth-5pent- 2eth-6hex- 3prop-7hept- 4but-8oct-
31
This method works well for straight-chain hydrocarbons like hexane. H H H H H H H C C C C C C H H H H H H H
32
We have to add rules to help deal with branched chains. H H H H CH 3 H H C C C C C C H H H CH 3 H CH 3 H
33
First draw out the full structure. H H H H CH 3 H H C C C C C C H H H CH 3 H CH 3 H
34
Number the atoms in the longest continuous carbon chain. Start at the end nearest most groups. H H H H CH 3 H H C C C C C C H H H CH 3 H CH 3 H 654321
35
This now gives us the basic name – in this case hexane. H H H H CH 3 H H C C C C C C H H H CH 3 H CH 3 H 654321
36
You must now identify any side chains. -CH 3 is methyl -CH 2 CH 3 is ethyl
37
Now identify and count the number and type of side chain. di - shows 2 tri – shows 3 tetra – shows 4 Label the carbon atom(s) they join
38
This now gives us the full name: 2,2,4 trimethylhexane. H H H H CH 3 H H C C C C C C H H H CH 3 H CH 3 H 654321
39
Naming alkenes works in the same way, except we start numbering at the end nearer the double bond. H H H H CH 3 H H C C C C C C H H C 2 H 5 CH 3 H
40
Number the atoms in the longest carbon chain. H H H H CH 3 H H C C C C C C H H C 2 H 5 CH 3 H 123456
41
This now gives us the basic name – in this case hex-2-ene. H H H H CH 3 H H C C C C C C H H C 2 H 5 CH 3 H 123456
42
Identifying the side chains gives us the full name: 5,5 dimethy 4 ethyl hex-2-ene. H H H H CH 3 H H C C C C C C H H C 2 H 5 CH 3 H 123456
43
We can use the same principles with cyclic hydrocarbons. H H C H C C H C C H H H CH 3
44
1 methyl cyclopentane H H C H C C H C C H H H CH 3 1 2 3 4 5
45
Isomers Isomers are compounds with the same molecular formula but different structural formulae For example C 4 H 10 H C C C C H H H butane H C C C H H H H H C H H H 2 methyl propane
46
Alkanols The alkanols form another homologous series. We can recognise the alkanols because they contain an OH group.
47
We can name the alkanols using the principles we have used before. H H CH 3 H H H C C C C C H H H H OH H
48
3 methyl pentan-2-ol H H CH 3 H H H C C C C C H H H H OH H 12345
49
Alkanoic acids The alkanoic acids form another homologous series. We can recognise the alkanoic acids because they contain a COOH group. C OH O
50
We can name the alkanoic acids using the principles we have used before. H H CH 3 H H H C C C C C H H H H H C OH O
51
4 methyl hexanoic acid We don’t need to number the acid group because it must be on the first carbon. H H CH 3 H H H C C C C C H H H H H 12345 C OH O 6
52
Esters An ester can be identified the ‘-oate’ ending to its name. The ester group is: C O O
53
Esters An ester can be named given the names of the parent alkanol and alkanoic acid. The name also tells us the alkanoic acid and alkanol that are made when the ester is broken down.
54
CH 3 CH 2 C OH O The acid and alkanol combine
55
HO CH 3 The acid and alkanol combine
56
CH 3 CH 2 C OH O HO CH 3 The acid and alkanol combine Water is formed.
57
CH 3 CH 2 C O O CH 3 H2OH2O
58
Naming esters Acid nameAlkanol nameEster name ethanoic acidmethanolmethyl ethanoate propanoic acidethanolethyl propanoate butanoic acidpropanolpropyl butanoate methanoic acidbutanolbutyl methanoate
59
A typical ester is shown below. H H O H H H C C C O C H H H H C H
60
We can identify the part that came from the alkanoic acid – propanoic acid. H H O H H H C C C O C H H H H C H
61
We can identify the part that came from the alkanol - ethanol H H O H H H C C C O C H H H H C H
62
This gives us the name ethyl propanoate H H O H H H C C C O C H H H H C H
63
Nomenclature and Structural Formulae Click here to repeat Nomenclature and Structural Formulae. Click here to return to the Menu Click here to End.
64
Reactions of Carbon Compounds
65
Saturated Hydrocarbons Alkanes and cycloalkanes are saturated hydrocarbons. Saturated hydrocarbons contain only carbon to carbon single covalent bonds.
66
Unsaturated Hydrocarbons The alkenes are unsaturated hydrocarbons. Unsaturated hydrocarbons contain at least one carbon to carbon double covalent bond.
67
It is possible to distinguish an unsaturated hydrocarbon from a saturated hydrocarbon using bromine solution (bromine water).
68
Take some bromine solution (brown) in test tube.
69
Add a few drops of an unsaturated hydrocarbon.
70
Unsaturated hydrocarbons decolourise bromine water. colourless
71
Addition Reactions Addition reactions take place when atoms, or groups of atoms, add across a carbon to carbon double bond. H H H H C C + * * C C * *
72
When bromine adds to an alkene we have an addition reaction. C 4 H 8 + Br 2 C 4 H 8 Br 2 H H H H C C + Br Br C C Br Br
73
The addition reaction between hydrogen and an alkene gives the equivalent alkane. propene + hydrogen propane C 3 H 6 + H 2 C 3 H 8 H H H H C C + H H C C H H
74
The addition reaction between water and an alkene gives the equivalent alkanol. propene + water propanol C 3 H 6 + H 2 O C 3 H 7 OH H H H H C C + H 2 O C C H OH
75
Cracking Hydrocarbons Fractional distillation of crude oil yields more long-chain hydrocarbons than are needed by industry. Cracking is an industrial method for producing a mixture of smaller, more useful molecules, some of which are unsaturated.
76
catalyst mineral wool soaked in oil heat gas
77
Cracking The cracking process can be carried out in different ways. Thermal cracking is where heat is used to split large molecules into smaller ones. Catalytic cracking is where a catalyst is used to split large molecules into smaller ones.
78
Catalytic Cracking A catalyst allows the reaction to take place at a lower temperature. Cracking can be carried out in the laboratory using an aluminium oxide or silicate catalyst. Some unsaturated hydrocarbons are produced because there are not enough hydrogen atoms to give completely saturated products.
79
Alcohol Alcohol (ethanol) is a drug. If we take too much alcohol it can have many harmful effects on our bodies and brains.
80
Ethanol, for alcoholic drinks, can be made by fermentation of glucose derived from any fruit or vegetable.
81
The type of alcoholic drink varies with the plant from which the glucose comes.
82
Fermentation During fermentation glucose is broken down to form ethanol; carbon dioxide is also produced. Fermentation is brought about by enzymes present in yeast. There is a limit to the amount of ethanol which can be produced by fermentation.
83
Distillation Distillation is a method of increasing the ethanol concentration of fermentation products in the manufacture of ‘spirit’ drinks. Water and alcohols can be partially separated by distillation because they boil at different temperatures.
84
Ethanol To meet market demand ethanol is made by means other than fermentation. Industrial ethanol is manufactured by the catalytic hydration of ethene. H H H H H C C H + H 2 O H C C H H OH
85
Ethanol can be converted to ethene by dehydration. H H H H H C C OH C C + H 2 O H H H H
86
Ethanol, mixed with petrol, can be used as a fuel for cars. The ethanol is obtained from sugar cane, a renewable source of energy.
87
Condensation Reactions In a condensation reaction, the molecules join together by the reaction of the functional groups to make water. H HO H2OH2O
88
Esters Esters are formed by the condensation reaction between a carboxylic acid and an alcohol. They can be recognised by the ester link: C O O
89
The ester link is formed by the reaction of a hydroxyl group of an alkanol with a carboxyl group of a carboxylic acid. H H HO C C H H H
90
The ester link is formed by the reaction of a hydroxyl group of an alkanol with a carboxyl group of a carboxylic acid. H H HO C C H H H
91
The ester link is formed by the reaction of a hydroxyl group of an alkanol with a carboxyl group of a carboxylic acid. H H O H C C C O H H H
92
The ester link is formed by the reaction of a hydroxyl group of an alkanol with a carboxyl group of a carboxylic acid. H H O H C C C O H H H
93
H H O H C C C O H H H Carboxylic acid H H HO C C H H H Alkanol
94
H H O H C C C O H H H HO C C H H H
95
H H O H C C C O H H H HO C C H H H Water is formed from hydrogen of one molecule and hydroxide from the other.
96
H H O H C C C O H H C C H H H H2OH2O Water is formed from hydrogen of one molecule and hydroxide from the other.
97
H H O H C C C O H H C C H H H H2OH2O Water is formed from hydrogen of one molecule and hydroxide from the other. The remains of the molecules join together
98
H H O H C C C O H H C C H H H H2OH2O Water is formed from hydrogen of one molecule and hydroxide from the other. The remains of the molecules join together
99
Hydrolysis Reactions In a hydrolysis reaction, a molecule is split up by adding the elements of water. H HO H2OH2O
100
The carboxylic acid and the alcohol from which the ester are made can be obtained by hydrolysis. CH 3 CH 2 COOCH 3 CH 3 CH 2 COOH + H 2 O + CH 3 OH
101
The formation and hydrolysis of an ester is a reversible reaction. Acid + alkanol Ester + water hydrolysis condensation
102
Reactions of Carbon Compounds Click here to repeat Reactions of Carbon Compounds Click here to return to the Menu Click here to End.
103
Plastics and Synthetic Fibres
104
Most plastics and synthetic (i.e. man-made) fibres are made from materials which come from oil. Plastics are selected for various uses, according to their properties e.g. lightness, durability, electrical and thermal insulation.
105
For some purposes synthetic materials are more suitable than natural materials. Plastics are selected for various uses, according to their properties e.g. lightness, durability, electrical and thermal insulation.
106
There are many examples of plastics which we use in our everyday lives Polythene Polystyrene Perspex PVC Nylon Bakelite Formica Silicones Kevlar Poly(ethenol).
107
Examples of Plastics and Synthetic Fibres Recently developed plastics are Kevlar, which is very strong Poly(ethenol), which readily dissolves in water Synthetic fibres, like polyesters are Terylene Nylon.
108
Biodegradable Biodegradable means "able to rot away". Most plastics are not biodegradable and so cause environmental problems of disposal. A plastic called biopol has been developed which is biodegradable.
109
Burning plastics Certain plastics burn or smoulder to give poisonous fumes. The poisonous fumes that are released depend on the elements present in the plastic.
110
All plastics can release carbon monoxide. P.V.C. can release hydrogen chloride Polyurethane releases hydrogen cyanide.
111
Thermoplastic or Thermosetting? A thermoplastic plastic is one which can be melted or reshaped (examples polythene, polystyrene, P.V.C.) A thermosetting plastic is one which cannot be melted and reshaped (examples bakelite in electrical fittings, formica in worktops)
112
Polymerisation A monomer is a small molecule which is able to join together with other, similar, small molecules. A polymer is the large molecule produced. This process is called polymerisation. Plastics and fibres (natural and synthetic) are examples of polymers. The making of plastics and synthetic fibres are examples of polymerisation.
113
Addition Polymerisation Many polymers are made from the small unsaturated molecules, produced by the cracking of oil. They add to each other by opening up their carbon to carbon double bonds. This process is called addition polymerisation.
114
H C H The ethene is attacked by an initiator (I*) which opens up the double bond I*
115
The ethene is attacked by an initiator (I*) which opens up the double bond I H C C* H Another ethene adds on. H C H
116
The ethene is attacked by an initiator (I*) which opens up the double bond Another ethene adds on. I H C H C C* H Then another H C H
117
The ethene is attacked by an initiator (I*) which opens up the double bond Another ethene adds on. Then another I H C H C H C C* H ….
118
Naming polymers The name of the polymer is derived from its monomer. MONOMERPOLYMER ***ene poly(***ene) ethene poly(ethene) propene poly(propene) styrene poly(styrene) chloroethene poly(chloroethene) tetrafluoroethenepoly(tetrafluoroethene)
119
Repeat Units You can look at the structure of an addition polymer and work out its repeat unit and the monomer from which it was formed. The repeat unit of an addition polymer is always only two carbon atoms long.
120
-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 - Repeat Unit CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 - -CH 2 -CHCl -CH 2 -CHCl -CH 2 -CHCl -CH 2 -CHCl - Repeat Unit CH 2 -CHCl -CH 2 -CHCl -CH 2 -CHCl -CH 2 -CHCl -CH 2 -CHCl -
121
Condensation Polymers Condensation reactions involve eliminating water when two molecules join. Condensation polymers are made from monomers with two functional groups per molecule.
122
Normally there are two different monomers which alternate in the structure e.g. HH and HOOH
123
The molecules join together, eliminating water as they do so. Hydrogen comes from one molecule. Hydroxide comes from the other molecule. The molecules join where these groups have come off. This repeats many times, joining together many of the monomers
124
H H HOOH
125
H H2OH2O HH
126
H H H2OH2OH2OH2O HOOH
127
H H2OH2OH2OH2OH2OH2O HH
128
H H2OH2OH2OH2OH2OH2OH2OH2O H HOOH
129
H H2OH2OH2OH2OH2OH2OH2OH2OH2OH2O
130
Repeat Units You can look at the structure of a condensation polymer and work out its repeat unit and the monomers from which it was formed.
131
-C-(CH 2 ) 4 -C-N-(CH 2 ) 6 -N -C-(CH 2 ) 4 -C-N-(CH 2 ) 6 -N- O O H H O O H H -C-(CH 2 ) 4 -C-N-(CH 2 ) 6 -N- O O H H -C-(CH 2 ) 4 -C-N-(CH 2 ) 6 -N -C-(CH 2 ) 4 -C-N-(CH 2 ) 6 -N- O O H H O O H H HO-C-(CH 2 ) 4 -C-OH O O H-N-(CH 2 ) 6 -N-H H H Polymer Repeat Unit Monomers and
132
Polymer Repeat Unit Monomers and -O-C-C 6 H 4 -C-O-CH 2 -CH 2 -O-C-C 6 H 4 -C-O-CH 2 -CH 2 - O O 0 O HO-CH 2 -CH 2 -OH -O-C-C 6 H 4 -C-O-CH 2 -CH 2 -O-C-C 6 H 4 -C-O-CH 2 -CH 2 - O O 0 O H-O-C-C 6 H 4 -C-O-H O O -O-C-C 6 H 4 -C-O-CH 2 -CH 2 - O O
133
Condensation Polymers Typical condensation polymers are polyesters and polyamides. Terylene is the brand name for a typical polyester. Nylon is a typical polyamide.
134
Polyesters As the name suggests polyesters are polymers which use the ester link. The two monomers which are used are a diacid and a diol.
135
The diacid will have a typical structure: The diol will have a typical structure: HOOH They combine like this: C-O-H O H-O-C O C-O-H O H-O-C O
136
The diacid will have a typical structure: The diol will have a typical structure: HOOH They combine like this: C-O-H O H-O-C O C-O-H O H-O-C O HOOH
137
The diacid will have a typical structure: The diol will have a typical structure: HOOH They combine like this: C-O-H O H-O-C O C-O O H-O-C O OH C-O-H O H-O-C O
138
The diacid will have a typical structure: The diol will have a typical structure: HOOH They combine like this: C-O-H O H-O-C O C-O O H-O-C O O C-O-H O -C O HOOH
139
The diacid will have a typical structure: The diol will have a typical structure: HOOH They combine like this: C-O O H-O-C O O C-O O -C O OH C-O-H O H-O-C O
140
Amines Amines are a homologous series containing the amine group: N H H
141
The amide link The amide link is formed when an acid and amine join together. N H H HO C O
142
The amide link The amide link is formed when an acid and amine join together. N H H HO C O
143
The amide link The amide link is formed when an acid and amine join together. NHNH C OC O H2OH2O
144
The amide link The amide link is formed when an acid and amine join together. NHNH C OC O The amide link
145
Polyamides A polyamide is made from a diamine and a diacid: H N H N H H diamine C-O-H O H-O-C O diacid They combine like this:
146
H N H N H H C-O-H O H-O-C O
147
H N H N H H H N H NHNH C-O-H O COCO H2OH2O
148
C-O-H O H-O-C O H N H NHNH COCO COCO N H N H H H2OH2O H2OH2O
149
H N H NHNH COCO COCO N H NHNH C-O-H O C O H2OH2O H2OH2O H2OH2O
150
Plastics and Synthetic Fibres Click here to repeat Plastics and Synthetic Fibres Click here to return to the Menu Click here to End.
151
Natural Products
152
Carbohydrates Carbohydrates are important foods, produced by plants. Carbohydrates act as an important source of energy for animals. Carbohydrates burn, releasing energy and producing carbon dioxide and water.
153
Carbohydrates contain the elements carbon, hydrogen and oxygen. There are two hydrogen atoms for each oxygen atom in carbohydrates e.g. C 6 H 12 O 6 and C 12 H 22 O 11
154
Sugars and Starch Carbohydrates can be divided into sugars and starches.
155
Sugars Sugars are sweet, dissolves well in water and let a beam of light pass through their solutions. Sugars are small molecules.
156
Examples of sugars include glucose, fructose, maltose and sucrose (table sugar). Monosaccharides have formula C 6 H 12 O 6. Disaccharides have formula C 12 H 22 O 11.
157
Starch Starch is not sweet, does not dissolve in water and does not let a beam of light pass through its solution. Starch is a condensation polymer, made of large molecules.
158
Testing Carbohydrates Benedict's solution (or Fehling's solution) gives a positive test (an orange colour) with glucose, fructose, maltose and other sugars but NOT sucrose. Iodine will turn blue/black in the presence of starch.
159
Photosynthesis Photosynthesis is the process by which plants make carbohydrates and oxygen from carbon dioxide and water, using light energy. 6CO 2 + 6H 2 O + energy C 6 H 12 O 6 + 60 2 Chlorophyll (the green colour in plants) is used to absorb the light energy.
160
Respiration Respiration is the process by which animals AND plants obtain the supply of energy that they need for growth, movement, warmth etc. They obtain this energy by breaking down the carbohydrate, glucose, using oxygen: C 6 H 12 O 6 + 60 2 6CO 2 + 6H 2 0 + energy
161
The Atmosphere The combination of respiration and photosynthesis lead to the balance of carbon dioxide/oxygen in the atmosphere. The clearing of forests with the loss of green plants, reduces the amount of photosynthesis taking place. This could alter the balance of the atmosphere, with a consequent danger to life on Earth.
162
Condensation Polymerisation Glucose monomers polymerise to form starch. Plants convert the glucose into starch for storing energy. This is a condensation polymerisation. nC 6 H 12 O 6 (C 6 H 10 O 5 ) n + nH 2 O
163
Hydrolysis Hydrolysis takes place when large molecules are broken down into smaller molecules by the addition of small molecules, such as water. The breakdown of starch is an example of a hydrolysis reaction.
164
Digestion During digestion starch molecules are broken down by the body into smaller glucose molecules that can pass through the gut wall into the bloodstream. The breakdown of starch is brought about using acid or the enzymes, such as amylase.
165
Sucrose and starch molecules break down by the addition of water: C 12 H 22 O 11 + H 2 O C 6 H 12 O 6 + C 6 H 12 O 6 sucrose glucose fructose (C 6 H 10 O 5 ) n + nH 2 O n C 6 H 12 O 6 starch glucose
166
Enzymes Enzymes, such as amylase, are biological catalysts An enzyme will work most efficiently within very specific conditions of temperature and pH. The further conditions are removed from the ideal the less efficiently the enzyme will perform.
167
Amino acids These are compounds which contain an amine group and an acid group. N H H R HO C C O H
168
There are about 25 essential amino acids. They are different because they have different side groups – shown by “R”. Condensation of amino acids produces the peptide (amide) link. N H H R HO C C O H
169
The peptide link The peptide link is formed when an acid and amine join together. (We have previously called this the amide link.) N H H R 1 HO C C O H N H H R 2 HO C C O H
170
The peptide link The peptide link is formed when an acid and amine join together. (We have previously called this the amide link.) NHNH R 1 HO C C O H N H H R 2 C C O H peptide link
171
Proteins Proteins form an important class of food made by plants. They are condensation polymers made of many amino acid molecules linked together. The structure of a section of protein is based on the constituent amino acids.
172
Proteins are used to make the main structures in animals – muscles, tissues etc. They also make important chemicals needed for the main processes of life such as enzymes, antibodies and hormones. Examples of these proteins are insulin and haemoglobin.
173
Amino acids polymerising N H H R 1 HO C C O H N H H R 2 HO C C O H
174
Amino acids polymerising NHNH R 1 HO C C O H N H H R 2 C C O H H2OH2O N H H R 3 HO C C O H
175
Amino acids polymerising NHNH R 1 HO C C O H NHNH R 2 C C O H H2OH2O N H H R 3 C C O H H20H20 N H H R 4 HO C C O H
176
Amino acids polymerising NHNH R 1 HO C C O H NHNH R 2 C C O H H2OH2O NHNH R 3 C C O H H20H20 N H H R 4 C C O H H2OH2O
177
Digestion During digestion enzymes hydrolysis the proteins in our diet to produce amino acids. The body then builds up the proteins it needs from those amino acids.
178
Fats and Oils Natural fats and oils can be classified according to where they come from: Animal Vegetable Marine
179
Fats and oils in the diet supply the body with energy. They are a more concentrated source of energy than carbohydrates. Oils are liquids and fats are solids. Oils have lower melting points than fats. This is because oil molecules have a greater degree of unsaturation.
180
Saturated fats: have more regular shapes than unsaturated oils:
181
This means that fat molecules fit together easily and have a low melting point
182
Oil molecules do not fit together easily and have a high melting point
183
Oils can be converted into hardened fats by adding of hydrogen. H2H2 H2H2 H2H2
184
Oils can be converted into hardened fats by adding of hydrogen. This is how margarine is made
185
Fatty acids Fatty acids are straight chain carboxylic acids, usually with long chains of carbon atoms. Fatty acids may be saturated or unsaturated.
186
Fats and oils are esters. They are made from the triol glycerol CH 2 OH CH OH CH 2 OH glycerol and fatty acids. R C OH O fatty acid
187
Fats and oils are esters. They are made from the triol glycerol CH 2 OH CH OH CH 2 OH glycerol and fatty acids. fatty acid HO C R O
188
HO C R 3 O CH 2 OH CH OH CH 2 OH HO C R 2 O HO C R 1 O Three fatty acids form esters with the three OH groups of glycerol.
189
C R 3 O CH 2 O CH CH 2 O O C R 2 O C R 1 O Three fatty acids form esters with the three OH groups of glycerol.
190
The hydrolysis of fats and oils produces fatty acids and glycerol in the ratio of three moles of fatty acid to one mole of glycerol. C R O CH 2 O CH CH 2 O O C R O C R O CH 2 OH CH OH CH 2 OH R C OH O + 3
191
Natural Products Click here to repeat Natural Products Click here to return to the Menu Click here to End.
192
The End Hope you found the revision useful. Come back soon!!
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.