Additional Applied Science - The Basics Flashcards
What do hazard symbols show?
Hazard symbols show if something is dangerous
What are safety signs used for?
Keeping people safe in the workplace
When should different fire extinguishers be used and what do they contain?
Red = water (for wood)
Black = CO2 (for electrical)
Cream = foam (for liquids)
Blue = powder (for gases)
What is the blood made up of and what does it carry?
Red blood cells, white blood cells, platelets and plasma
The blood carries amongst other things oxygen and glucose to all the cells
What are the three types of blood vessel and what do they do?
Arteries – blood away from the heart
Veins – blood back to the heart
Capillaries – exchange of material at the tissues
When we breathe what gas do we need to inhale and what gas do we need to exhale?
We need to inhale oxygen and exhale carbon dioxide (for respiration)
What is aerobic respiration?
Aerobic respiration is the release of energy from glucose using oxygen
What is anaerobic respiration and what is the problem with it?
Aerobic respiration is the release of energy from glucose without oxygen – it leads to an oxygen debt
What does recovery time depend on?
Recovery time depends on fitness
How does the body regulate body temperature?
If the body is too hot it sweats, blood vessels dilate and hair lays flat
If the body is too cold it shivers, blood vessels constrict and hair stands on end
How does the body regulate sugar levels?
If there is too much glucose then insulin is released which stores excess sugar
If there is too little sugar then insulin is now longer released (and glucagon is) which releases excess sugar
How are glucose levels measured?
Using a dipstick (urine sample measured on a colour chart to identify if any glucose is present)
How is muscle strength measured?
Using the grip test
How do muscles move bones?
Bones are held together by ligaments
Bones are attached to muscles by tendons and the muscles contract to pull on the bone and move it
Muscles usually come in antagonistic pairs (e.g. biceps and triceps) as muscles can only pull (not push)
What is a moment and how is it worked out?
A moment is a turning force
Moment = force x distance
What materials are suitable for artificial joints?
Materials which are durable, lightweight but do not react with the body (e.g. titanium)
What does body mass index (BMI) show?
BMI shows underweight / overweight people
BMI = mass ÷ height2
<18.5 = underweight
18.5-24.9 = normal
25-29.9 = overweight
How do sports drinks help an athlete?
Sports drinks contain water, glucose and electrolytes which are lost during exercise (isotonic drinks)
How are good safety standards promoted?
Products carry a BSI or CE mark meaning the product has been tested for safety and is fit for purpose
What is compressive and tensile strength?
Materials can have a high compressive strength (cannot be crushed easily) and a high tensile strength (resist being stretched)
What properties can materials have to be useful?
Stiffness
Flexibility
Toughness
Brittleness
Hardness
Density
What is electrical and thermal conductivity?
Electrical conductivity is the ability for a material to conduct electricity (e.g. copper wire)
Thermal conductivity is the ability for a material to conduct heat (e.g. a saucepan)
What are the properties of ceramics?
Ceramics are hard (but break easily) and are very poor conductors (e.g. used as a coffee cup)
What are the properties of metals?
Metals are strong but flexible (alloys are a mixture of metals)
What are the properties of polymers?
Polymers are plastics which are flexible, are good insulators, have a low density (e.g. a plastic bag / electrical wire shielding)
What are the properties of composites?
Composites are two or more different materials (e.g. glass reinforced plastic for windscreens)
What is the difference between a natural and synthetic material?
Synthetic: man made materials which can be more durable / cheaper
Natural: found naturally and are usually biodegradable
Who regulates the food industry?
FSA and DEFRA
What can cause food poisoning?
Microorganisms
How can hygiene be improved in areas used for cooking?
Keep yourself clean
Use disinfectants / detergents
Use heat to sterilize equipment
Dispose of waste properly
Control pests
How can bacteria be slowed / stopped?
Refrigeration
Freezing
Heating
Drying
Salting / Pickling
How do streak plates help identify bacteria?
Wire loop to get rid of any bacteria / dip the loop into the sample / spread onto agar plate and leave to grow
How are bacteria useful in food production?
How are yeast useful in food production?
Bacteria are used to make cheese / yoghurt
Yeast are used to make bread / alcohol
What minerals are needed for plants to be healthy?
Nitrates
Phosphates
Potassium
Magnesium
How does intensive farming maximise the amount of food which can be produced?
Artificial fertilisers, pesticides, fungiscides and herbicides help plants grow and pests destroyed
Livestock are kept in warm restricted areas to reduce energy loss
What is organic farming?
Organic farming methods do not use chemicals (weeds are pests are controlled by hand / natural pesticides and predators) and livestock have more room to move
What is selective breeding?
Only allowing certain animals to breed so traits you want are shown (e.g. only big cows are bred)
What is genetic engineering?
Transferring genes from one organism to another
How is artificial fertiliser made?
Artificial fertilisers are made via a neutralization reaction
Ammonia + Nitric Acid >>> Ammonium Nitrate + Water
How is percentage yield calculated?
Percentage yield = (actual yield ÷ theoretical yield) x 100
How can a reaction be sped up?
Increase temperature
Increase concentration
Increase pressure
Use smaller particles
Add a catalyst
What are the properties of an ionic compound?
Ionic compounds have charged particles – they have high melting points
What are the properties of a covalent compound?
Covalent compounds have low melting and boiling points
What are the flame tests for metal ions?
What are the flame tests for metal ions?
How are carbonates tested for?
Add dilute acid – carbon dioxide is given off is a carbonate is present
How are sulfates tested for?
Add hydrochloric acid then barium chloride – if a white precipitate forms a sulfate is present
How are chlorides tested for?
Add nitric acid then silver nitrate – if a white precipitate forms a chloride is present
What is the test for ethanol?
Acidified potassium dichromate tests for ethanol (turns from orange to green)
Acidified potassium dichromate tests for ethanol (turns from orange to green)
Place dot of ink on chromatography paper; place paper in water; as water travels up the paper the ink is separated…
What is titration?
What can it be used for?
Titration is used to add exact quantities of solution – a known concentration of acid can be used to work out the concentration of an unknown alkali (or vice-versa)
How can Rf values be calculated?
Different chromatograms and the separated components of the mixtures can be identified by calculating the Rf value
What is contained in blood?
Blood plasma, red blood cells, white blood cells and platelets
What are the 4 main blood groups?
A
B
O
AB
What is refractive index?
Refractive index is the bending of light (due to refraction) in different mediums
