food. a balanced diet – what nutrients? energy warmth repair of tissues chemical reactions in body
TRANSCRIPT
Food
A balanced diet – what nutrients?
energy
warmth
repair of tissues
chemical reactions in
body
Why do we need vitamins?
And minerals?
How much energy do each of the following need?
pensioner
footballer office worker
builder
2000 kcal 4000 kcal
2500kcal 4500 kcal
Additives…
antioxidants
flavourings and flavouring enhancers
colourings preservatives
thickeners
sweeteners
Additives – good or bad?Advantages Disadvantages
Cochineal
In the 19th century the insects were imported and grown on a large scale on the Canary
Islands In 1868, the Canary Islands exported six million pounds of cochineal, equivalent to
420.000.000.000 insects....
Cochineal became widely used as a food colouring in cakes, cookies, beverages, jam,
jelly, ice cream, and sausages.
Food labelsName of product
How to store
product
Best before or use by
date
Ingredients list
Weight of product
Amount of each
nutrient
Allergy advice
Fairtrade or healthy
eating logos
Food tests
Test for starchTest for protein
Test for sugar
Test for fats
Test for acidity
Quantitative food tests
Moisture content
Suspended matter
Acidity content
Vitamin C content
Iron content
• What are the five nutrients needed for?• Name four minerals and their uses.• What additives are likely to be found in:a) Lemonade b) Sweets c) Low-calorie ice cream
• Give an advantage and disadvantage of additives.
• What things might you find on a food label?
• What are the tests for:a) Fat b) Starch c) Protein
Making cheese and yoghurt
curd
whey
Using yeast to make bread
Sugar → carbon dioxide + ethanol
Making beer!
barley
sugary solution
beer
yeast
Caused by…?
Symptoms…?
Prevented by…?
Kitchen hygiene
Food preservation
Detecting bacteriaStreak plates
Aseptic techniquesSerial dilution
• Describe the process of making cheese.• Why is yeast used when making bread?• What does yeast do to the sugar in the
production of wine?• Give three symptoms of food poisoning.• Give three ways of preventing food
poisoning.• Give four conditions bacteria need to
survive.• Describe how to do a serial dilution.
Minerals for plants…
Nitrates - greeN
PHosphates – Fruit and roots
Magnesium - green
Potassistem
Farming – which is better?
Intensive OrganicFertilisers
Pest control
Animals
Fertilisers
Pest control
Animals
• Why do plants need nitrates, potassium and magnesium?
• What is intensive farming?• What is battery farming and why is it
used?• What is meant by biological control?• How does removing hedges have a
bad effect on the environment?• Give three advantages and three
disadvantages of organic farming.
Forensics
Collecting evidence
How do we avoid contamination?
How do we collect evidence?
How do we record the evidence?
What marks do we find and how do we record them?
How do we compare impressions and marks?
How do we take fingerprints?
What do fingerprints look like?
Analysing crime scene Analysing crime scene evidenceevidence
Ionic compoundsCl-
Cl-
Mg2+
Covalent compounds
Why has this man collapsed?
Microscopes
Comparison microscopes
Polarising microscopes
Electron microscopes
Blood and blood groups
Blood group Antigens Does it clot with anti A antibodies
Does it clot with anti B antibodies
A A No yes
B B Yes No
AB A, B Yes Yes
O NONE no no
DNA Profiling
DNA
Found in…
DNA profiling…
GlassAngle of incidence
Angle of refraction
Dye stain on clothes
• What is contamination?• Why must contamination be avoided
at a crime scene?• How would you collect fibres?• Describe how to make a cast
impression.• What is a fingerprint and what are
the three types?• How would you collect soil?
Flame tests for metal ions
Tests for solubility
Tests for carbonates using dilute acid
Tests for sulphates using hydrochloric acid and
barium chloride
Tests for metal ions
Metal ion Colour of precipitate
Calcium White
Copper Blue
Iron (II) Sludgy green
Iron (III) Red brown
Lead White at first but will turn colourless with more sodium hydroxide
Tests for chlorides
Tests for ethanol Tests for glucose
In a flame test you see a brick red colour.
When you add sodium hydroxide you see a white precipitate.
When you add nitric acid and silver nitrate you see a white precipitate.
What is the substance?
What else do forensic scientists use?
Databases
loop
arch
whorl
• How do you use flame tests to test for copper?
• How do you test for carbonates and sulphates?
• How do you test for solubility?• How would you use sodium
hydroxide to test for calcium?• How would you test for ethanol and
glucose?• Name three databases forensic
scientists use.
Sports
Being successful in sport
FITNESS
FOOD
EQUIPMENT
SKILL
PERFORMING UNDER PRESSURE
The Cardiovascular System
The heart
The lungs
1
2
3
4
5
6
7
8
9
The respiratory system
BreathingBreathing in
Intercostal muscles contract, pulling ribcage up and outDiaphragm contracts and flattens outContracting muscles make chest cavity largerPressure inside lung decreases so air is drawn in
Breathing out
Intercostal muscles relax, ribcage drops in and downDiaphragm relaxes and arches upRelaxing muscles make chest cavity smallerPressure inside lung increases so air is forced out
Measuring lung capacity – use a spirometer
Inspiratory reserve volume
Expiratory reserve volume
Vital capacity
Tidal volume during exercise
Tidal volume at rest
Residual volume
To use a spirometer
2. Divide your reading by 3 to get an average tidal volume.
1. Breathe normally into the spirometer 3 times.
To get tidal volume
To get vital capacity
1. Breathe in as far as
you can through your
nose then out as far as
you can through your
mouth.
2. Repeat 2 more
times and use the highest
value.
Respiration
Aerobic respiration
Anaerobic respiration (without oxygen)
Glucose + oxygen carbon dioxide + water + energy
Glucose lactic acid + energy
Recovery rate
Heart rate / beats per minute
Time / minutes
Ed’s
Jo’s
Controlling body temperature
Too hot??
Too cold??
Normal body temperature
is 37°c
Controlling water and glucose
Why must we control our water levels? How do
we do it?
And what about
glucose?
How to measure glucose levels
Testing urine
Testing blood
The action of musclesMuscles are attached by tendons to bones
Testing muscle strength
What do you have to do to test muscle strength?
Daily basic energy requirements
BER (Kcal/day) = 1.3 x 24 hours x body mass (kg)
Body mass index
BMI = body mass / (height2)
Sports clothing and footwear
Item Used to be made of…
Now made of…
Because…
Cycling helmets
Motorbike jacket
Friction between…
and… means that…
so we…
Running shoes
Running track
Bicycle wheel
Brake pad
Canoe Water
Canoe paddle
Water
Bicycle helmet
Air
Materials in sport
Metal Wood
Ceramics
CompositesPolymers