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C1 Revision. Food additives. Make food look and taste better, and last longer. Anti-oxidants stop the food from reacting with oxygen. Emulsifiers help.

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Presentation on theme: "C1 Revision. Food additives. Make food look and taste better, and last longer. Anti-oxidants stop the food from reacting with oxygen. Emulsifiers help."— Presentation transcript:

1 C1 Revision

2 Food additives. Make food look and taste better, and last longer. Anti-oxidants stop the food from reacting with oxygen. Emulsifiers help oil and water mix. –Hydrophobic and hydrophilic. The E means it has passed a safety test, the number tells you what it does.

3 Cooking. Proteins denature. –Heat changes their shape permanently. Starch grains burst. Cooking is an irreversible chemical change. NaHCO 3 → Na 2 CO 3 + CO 2 + H 2 O

4 Perfume. Acid + Alcohol → Ester and Water. –Easily evaporates. –Non toxic. –Doesn't react with water. –Doesn't irritate your skin. –Insoluble in water.

5 Solutions. A solute dissolves in a solvent making a solution. Its all about attraction. –The solvent needs to be able to break the bonds of the solute and make stronger bonds with them.

6 What is oil made of??? Oil is a Mixture of Hydrocarbons They are called: Alkanes and Alkenes

7 Chemicals Name chemical formula display formula 3d shape. methane, CH 4 C H H H H

8 An example of an alkane Methane All single bonds Saturated

9 an example of an alkene Ethene Contains a double bond unsaturated

10 Alkanes and alkenes. Alkanes: –C-C –‘saturated‘ –C n H 2n+2 –Can’t make polymers. –Very unreactive. –Does nothing to bromine water. Alkenes: –C=C –'unsaturated' –C n H 2n –Used to make polymers. –Very reactive. –Turns bromine colourless.

11 Naming hydrocarbons NO. OF CARBONSNAME 1Meth- 2Eth- 3Prop- 4But- 5Pent-

12 Fractional distillation. Hydrocarbon molecules contain only carbon and hydrogen atoms. Crude oil can be separated by fractional distillation, –because they have different boiling and condensation points. The crude oil is heated to vapourise it (evaporated or boiled). The most volatile fraction, i.e. the molecules with the lowest boiling points, boil or evaporate off first and go to the top of the column.

13 How do we separate this mixture?? Fractional Distillation As you go up the column to the: –Boiling point decreases –Intermolecular forces decrease –Volatility/ignition increases

14 Hydrocarbon Bonds. Down the pic above the molecule gets...... bigger as the carbon atom number in the molecule increases.... more viscous as the intermolecular forces between molecules increases.... higher melting point as more energy is needed to overcome the intermolecular forces holding the molecules together.... higher boiling point as more energy is needed to overcome the increasing intermolecular forces between the liquid molecules.... less flammable as they become less volatile, again due to increasing intermolecular forces.

15 How do we make the fractions more useful?? What process is used to break long carbon molecules (like tar) into smaller, more useful molecules (like petrol)? Cracking Need a catalyst High pressure

16 Cracking. In the catalytic cracker long chain molecules are split apart or ‘cracked’. This is another example of thermal decomposition. C 8 H 18  C 6 H 14 + C 2 H 4 + ethene Octane hexane Ethene is used to make plastics Heat pressure catalyst Used as a fuel

17 Polymers. Monomers stick together and make polymers. Unsaturated monomers have a double bond between 2 carbons. HH CC H HH HH C C HH HH CC HH HH CC HH HH CC HH And lots more.. addition polymerisation This is called addition polymerisation and is written as: Pressure high temperature catalyst n n ethene poly(e)thene 1 2 3 4 5 thousands CC H H H H CC H H H H C C HH HH

18 Making Polymers What do we start with??? An AlKENE

19 Making Polymers The DOUBLE bond is broken leaving:

20 Polypropene polymerisedEthene is only one alkene. Other unsaturated molecules such as propene, vinyl chloride and styrene can also be polymerised to produce a range of plastics. E.g. propene Poly(propene) n n propene

21 pvc CC HH H Cl n n Vinyl chloride CC Cl H HH PVC

22 Fuels. Oil is running out, and is none renewable. Oil slicks, acid rain, and green house problems. Things that are important about choosing fuels are: –How much energy it gives out. –How much it costs. –How easy it is to store. –How poisonous it is. –How much pollution it gives off.

23 Burning fuels. Burning hydrocarbons always gives off water vapour. Enough oxygen allows complete combustion giving off carbon dioxide as well. Too little oxygen gives off carbon monoxide instead (and less oxygen). Cobalt blue goes pink for water Lime water goes cloudy for carbon dioxide.

24 Burning hydrocarbons The apparatus below is used to test the products of combustion of a hydrocarbon. any hydrocarbon + oxygen  water + carbon dioxide Suction pump Candle wax is the hydrocarbon here ice- water Liquid collected can be tested with anhydrous cobalt chloride paper (blue  pink). Lime water

25 Incomplete Combustion of Alkanes In the absence of an adequate supply of air, alkanes may react to form carbon monoxide and water. Carbon monoxide is highly poisonous and this is one reason why gas boilers must be serviced regularly. Methane + oxygen  water + carbon monoxide 2CH 4 + 3O 2  4H 2 O + 2CO A carbon monoxide detector


27 Energy. Exothermic –Gives out energy –More bonds are made than broken Endothermic –Takes in energy. –More bonds are broken than made. It takes 4.2 Joules of energy to increase the temp of 1g of water by 1C Energy transferred (J) = mass of water (g) x 4.2 x temp change (C) Energy of fuel (J/g) = energy transferred (J) / mass of fuel burnt (g)

28 Energy for the Home Module P1 Revision The thermal energy in a mass is the total energy of all the particles in the mass Thermal energy (heat) is measured in joules (J) The temperature is a measure of how hot something is (how fast the average particle is moving) Temperature is measured in degrees Celsius (°C)

29 Like water flowing downhill, from higher places to lower places Thermal energy transfers from high temperature places to low temperature places The bigger the temperature difference the quicker the heat energy transfers

30 The Thermogram Temperature is shown by the colour Hot = red/yellow Cold = blue

31 Heating and Cooling To raise the temperature of an object energy must be added (by heating it) To lower the temperature of an object energy must be taken away (by cooling it)

32 Specific Heat Capacity, SHC The amount of energy added or subtracted to change the temperature of a substance depends on: Its mass The material The temperature change

33 Specific Heat Capacity, SHC The Specific Heat Capacity of a substance is the energy needed to change the temperature 1 kg of the substance by 1 o The greater the SHC the more heat energy it can store

34 Specific Latent Heat, SLH When a solid melts or a liquid boils it requires energy, even though its temperature does not change The energy is needed to break the bonds between the molecules

35 Specific Latent Heat, SLH When a liquid solidifies or a gas condenses energy is released even though the temperature does not change The energy is released as the atoms or molecules join together and slow down

36 Specific Latent Heat, SLH The Specific Latent Heat, SLH, is the energy required or released by 1 kg of a substance when it melts or freezes, evaporates or condenses

37 Changes of state

38 Insulation Air is a good insulator, (all gases are good insulators) Any material that traps pockets of air is a good insulating material Eg: Expanded polystyrene, fibreglass wool, Double glazing, feathers, fur

39 Insulating the house Loft insulation Cavity Wall insulation Double glazing Carpets Draught excluders

40 Payback time Payback time = Original cost ÷ annual saving

41 Efficiency The more efficient a machine or device is, the more of its INPUT energy is transferred into a USEFUL energy OUTPUT 100 J Electrical Energy INPUT 90 J Light Energy USEFUL OUTPUT 10 J Heat Energy WASTED OUTPUT Efficiency = 90/100 = 0.9 = 90%

42 Payback time Money spent on insulating your home is money well spent – but some methods are better than others: Loft insulation may cost £500 to buy, and save £250 each year in heating costs So it would take 2 years to save the original cost: Payback time is 2 Years

43 Heat Energy Transfer (1) CONDUCTION:- Transfer of Thermal Energy via particle to particle, atom to atom –Mainly occurs in solids –“Hotter” Particles/atoms vibrate faster, taking up more space so the solid expands –Best conductors are metals, due to free electrons enabling rapid transfer of energy

44 Heat Energy Transfer (2) CONVECTION:- transfer of heat energy through liquids and gases –“Hotter” particles/atoms move faster, so they take up more space and the gas or liquid expands and becomes less dense –“Hotter,” less dense, masses of water or air will rise –“Colder”, more dense, masses of water or air will sink CONVECTION CURRENTS will develop, transferring energy everywhere else

45 Heat Energy Transfer (3) RADIATION:- EVERY object that is HOTTER than its surroundings will emit heat energy as INFRARED RADIATION until it is the same temperature as its surroundings This can be seen by infrared cameras and sometimes felt by the skin

46 INFRARED (1) Black surfaces absorb infrared best –Black cars get hot in the sun, white ones stay cool Black surfaces emit infrared best –Radiators should be black – but who wants black radiators? White/silver surfaces reflect infrared –NEWS FLASH! Space tourists travel to the sun behind a giant mirror and survive! White/silver surfaces emit least –So why is my radiator white?!

47 INFRARED (2) USED FOR: –Burglar alarms: “heat sensors” detect infrared –Cooking: infrared heats the surface of food, cooking it –Control: Remote controls for TVs, videos, DVDs –Information: transfer of data to/from computer mouse

48 MICROWAVES Have longer wavelength (lower frequency) than infrared, so transfer less energy. Are reflected by metals, but go through plastics and glass Used by mobile phones, satellites and radar One particular wavelength used for cooking because it is absorbed by water molecules which then move more quickly (ie they get “hotter”) – this then cooks the food

49 ANALOGUE SIGNALS These are waves that continuously vary They can have many different values Any interference can not be removed: signal quality can only get worse

50 DIGITAL SIGNALS These are waves that only have two values: –High/Low 1 or 0 On/Off Interference or distortion can be removed or is not recognised by the receiver Signals can be boosted or amplified without increasing interference

51 DIGITAL SIGNALS Surface of DVD disc Digital signal Computer Binary Code

52 WAVES in general Wavelength Amplitude Frequency = number of cycles (0scilations) per second (Hertz) Speed of wave (m/s) = wavelength (m) x frequency (Hz)

53 Wave Characteristics There are two main types of wave –Longitudinal, e.g. Sound, P-waves –Transverse, e.g. Light, S-waves Energy flow Vibrational direction Transverse WaveLongitudinalWave

54 Wave Characteristics All waves can be REFLECTED The angle of reflection = the angle of incidence

55 TOTAL INTERNAL REFLECTION Optical fibres can carry signals without losing as much energy Signals are more secure: more difficult to listen in

56 Wave Characteristics All waves can be REFRACTED Because light SLOWS down in more dense materials like glass

57 Wave Characteristics All waves can be DIFFRACTED When a gap or obstacle is the same width as the wavelength the waves spread out through it, or around it When the wavelength is smaller the spreading is less obvious

58 ELECTROMAGNETIC WAVES Electromagnetic waves are transverse At the lowest energy, lowest frequency and longest wavelength are radiowaves Next come microwaves, infrared, visible, ultraviolet, x-rays At the highest energy, highest frequency and shortest wavelength are gamma rays

59 LASERS Laser light consists of lightwaves that are all in phase with each other This makes a tight beam with great intensity Can be used to cut wood, steel and flesh with great accuracy Reflects precisely off CD and DVD discs

60 Wireless Technology Transmitter and receiver do not need to be physically connected Available 24/7 Radio waves can be reflected around the world through the IONOSPHERE (a layer of ionised air high in the atmosphere)

61 Wireless Technology Microwaves can be sent around the world by being RECEIVED and RE-TRANSMITTED from geostationary satellites Microwaves can be transmitted from phone mast to phone mast if in line of sight NOT TO SCALE

62 INTERFERENCE Different TV and radio channels use different frequencies to broadcast their programs If these frequencies are nearly the same the receiving TV or radio will get both programs – this is INTERFERENCE

63 SEISMIC WAVES : P-WAVES P-Waves = Primary waves = “Pressure” waves = longitudinal waves Are transmitted through solids, liquids and gasses The denser the substance the quicker they travel Sound travels at –330m/s in air1500m/s in water5000m/s in steel

64 SEISMIC WAVES : S-WAVES S-waves = Secondary waves = “sideways” waves = transverse waves Only travel through solids or semi solid material Travel more slowly through the Earth than P- Waves

65 Structure of the Earth This is what the interior looks like – we think! But how do we know?

66 Structure of the Earth If the Earth was simply solid all the way through –Then the waves from an earthquake would be felt everywhere around the world

67 STRUCTURE OF THE EARTH What the S-Waves tell us Observation: The S-Waves are not detected over nearly half of the Earth Explanation: The waves are blocked by a Liquid Core

68 STRUCTURE OF THE EARTH What P-Waves tell us Observation: There is a shadow zone where P-Waves are not detected Explanation: A liquid core causes refraction of the waves

69 ULTRAVIOLET RADIATION UV radiation can damage DNA in skin cells Small amounts cause tanning Large amounts may cause skin cancer Dark skin absorbs some UV reducing the amount reaching the deeper layers of skin The OZONE layer absorbs some UV reducing the amount reaching the Earth’s surface CFCs reduce OZONE, CFCS have been banned from current use

70 CLIMATE CHANGE The Earth’s climate changes naturally as the sun changes Volcanic dust and ash and man- made pollution can reflect sunlight away – cooling the planet Greenhouse gases “trap” heat in – warming the planet Greenhouse gases include CO 2, Methane and Nitrous Oxides (NOXs)

71 That’s all folks Remember –Read the question at least twice, or until you understand what it is asking you –If the question asks you to “Describe...” or “Explain…” then write a complete sentence for each mark that can be given –Read through your answers to make sure that they make sense –Nonsense award Examiners marks cannot for!

72 Biology Unit 1

73 What’s the difference between fitness and health?

74 Fitness is ability to do physical activity Health is being free from infection

75 How can we measure fitness? Strength Stamina Speed Flexibility Agility Cardiovascular efficiency

76 How many words can you find that are to do with fitness and exercise?


78 Your beating heart gives your blood pressure Blood pressure can be: –Diastolic (When the heart relaxes) –Systolic (When the heart contracts) What are the units for blood pressure? –mmHg

79 Blood pressure too high?! Burst blood vessels Damage to brain Stroke Kidney damage

80 Blood pressure too low?! Dizziness Fainting Poor circulation

81 Blood pressure is affected by age and lifestyle (diet, smoking, alcohol…)

82 RESPIRATION What’s the equation?










92 Can you remember it? Try saying it to yourself!

93 Glucose + oxygen  carbon dioxide + water + (energy)

94 FATIGUE When we do hard exercise, we respire ANAEROBICALLY and LACTIC ACID builds up in our muscles.

95 ANAEROBIC RESPIRATION Respiration without oxygen! Glucose  lactic acid + energy MUCH LESS ENERGY RELEASED IN ANAEROBIC RESPIRATION

96 BALANCED DIETS Vary depending on age, gender and amount of activity Carbohydrate – The body’s energy resource Fat – An insulator and an energy resource Protein – For growth and repair Vitamins – Keep the body functioning Minerals – Keep the body functioning Fibre – Keeps food moving along the gut

97 Can you remember the food types and what they are needed for? Carbohydrate – The body’s energy resource Fat – An insulator and an energy resource Protein – For growth and repair Vitamins – Keep the body functioning Minerals – Keep the body functioning Fibre – Keeps food moving along the gut



100 PROTEINS Are made from… AMINO ACIDS

101 Animal proteins are known as ‘first class’ proteins… …because they contain all the essential amino acids the body needs. Lack of protein causes KWASHIORKOR

102 BMI (body mass index) = mass (g) (height (m)) 2 BMI can be used to help us understand whether a person is underweight, normal, overweight or obese

103 A desire for perfection, low self-esteem and poor self image can lead to a poor diet and increased risks of poor health.

104 DIGESTION Chemical digestion is the break down of large insoluble food molecules into smaller more soluble ones by enzymes for absorption into the blood plasma or lymph. CAN YOU MEMORISE IT? Chemical digestion is the break down of large insoluble food molecules into smaller more soluble ones by enzymes for absorption into the blood plasma or lymph.



107 PROTEIN is broken down by PROTEASE

108 FAT/LIPID is broken down by LIPASE

109 Where does digestion take place? The mouth The stomach The small intestine Stomach acid aids enzyme function. Small molecules are absorbed into the blood in the small intestine by DIFFUSION.


111 Diseases and disorders can be caused by: Infectious microbes Genetic inheritance Vitamin deficiency Mineral deficiency

112 DEFICIENCIES No vitamin C  Scurvy No iron  Anaemia BODY DISORDERS Inability to control blood sugar level  diabetes GENETIC DISORDERS Red – green colour blindness

113 Diseases like MALARIA are caused by PARASITES. MALARIA is spread when the parasite is carried from person to person by a mosquito (the vector). How can knowledge of how vectors spread disease help to control infection

114 Immunity to disease Active: –The body remembers a pathogen invasion and white blood cells can respond quickly next time it happens! Passive: –Injecting a person with antibodies (e.g. Protection from a snake bite)

115 The immune response The body’ white blood cells produce antibody, specific to the pathogen

116 Can you order these pictures? 1 2 3 4 5

117 THE EYE Can you remember the labels?



120 What is this? A motor neurone CAN YOU REMEMBER THE LABELS?

121 Sensory neurones carry impulses ________ from a sense organ. Motor neurones carry impulses to an _________ (muscle or gland) away effector


123 What are the effects of the following types of drug? Depressants Hallucinogens Painkillers Performance enhancers Stimulants

124 Depressants – slow down brain function Hallucinogens- change what a person sees/hears Painkillers – Stop nerve impulses so no pain is felt Performance enhancers – develop muscles Stimulants – speed up brain function

125 The effects of drinking alcohol Do silly things Easily lose balance Find it hard to talk clearly Liver cirrhosis Drink driving

126 The effects of smoking tobacco Nicotine is addictive Carbon monoxide reduces oxygen absorption Particulates collect and block lungs Tar causes lung cancer


128 HOMEOSTASIS Keeping everything in balance –Water –Temperature –Blood sugar –Hormones


130 Female sex hormones, progesterone and oestrogen, are produced in the ________ The male sex hormone, testosterone, is produced in the ________ The pancreas produces the hormone _______, which controls blood sugar level ovaries testes insulin

131 The genetic code is a set of instructions that provide each organism with its characteristics

132 DNA is a double helix It looks like a twisted ladder The rungs of the ladder are made up of 4 bases.

133 Females have 2 ‘X’ chromosomes

134 Males have an X and a Y chromosome

135 Humans have 46 chromosomes (23 pairs) Human sex cells (gametes) contain 23 chromosomes When two sex cells meet  23 +23 = 46! THIS IS FERTILISATION

136 How do we get our characteristics? Genes are inherited Humans show variation (we all have differences) What causes variation?

137 Causes of variation Genes mixed up in gametes Genes coming from two different parents (fertilisation) Mutations –Radiation –Chemicals (mustard gas)

138 Can you think of any conditions that are inherited?

139 Red – green colour blindness Cystic fibrosis Sickle cell anaemia Haemophilia

140 DOMINANT OR RECESSIVE? Dominant characteristics: –A curved little finger –Ability to roll your tongue Dominant characteristics tend to be more common than recessive characteristics.

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