Science Y08 Aut1 Flashcards
List the 7 parts of a balanced diet.
carbohydrate, protein, fat (lipid), vitamins, minerals, fibre, water
Why do we need each of these nutrient groups?
carbohydrates for energy, protein for growth and repair, fats as an energy store, vitamins and minerals for vital cell processes, fibre keeps digestive system moving and healthy, water for cell function
What do we use to test for starch?
iodine- changes orange to black
Write the sequence of organs in the digestive system from mouth to anus.
mouth, oesophagus, stomach, small intestine, large intestine, rectum, anus.
What is the purpose of digestion?
The purpose of digestion is to break down large food particles into small ones so they can be absorbed into the blood and carried around the body.
What does the stomach contain and why?
The stomach contains acid (HCl) which destroys harmful bacteria and makes the pH right for digestion of protein.
What happens in the small intestine?
In the small intestine, small food particles are transferred from the digestive system into the blood.
What is an enzyme?
An enzyme is biological catalyst.
What do enzymes do?
A catalyst is something which speeds up chemical reactions, so an enzyme is something which speeds up chemical reactions in living things.
Why do we need enzymes?
We need enzymes to speed up the breakdown of large food particles into small food particles.
Where are enzymes produced?
salivary gland, stomach, pancreas, small intestine
What are pathogens?
disease causing micro-organisms
Name three types of pathogen.
bacteria, viruses and fungi
Define a non-communicable disease.
A non-communicable disease is one that is not caused by a pathogen and cannot be spread.
What happens in the respiratory system of a person suffering from asthma?
If you have asthma, your bronchioles can become inflamed, swollen and constricted (narrowed), and excess mucus is produced.
List 3 lifestyle factors that can be bad for health.
smoking, drinking alcohol, having an unbalanced diet
Classify the following drugs as stimulants or depressants: alcohol, caffeine, heroine, cannabis, cocaine, MDMA.
stimulants: caffeine, cocaine, MDMA. Depressants: heroine, cannabis, alcohol
Define obesity.
Obesity is being very overweight.
Describe what happens when the energy you take in as food and drink is more than the energy you use.
If your energy intake is more than your energy use, then you will gain weight.
What is malnutrition?
Malnutrition is not having enough, or having too much, of one or more of nutrients.
What is the name for a solid turning into a liquid and a liquid turning into a solid?
melting and freezing
What is the name for a liquid turning into a gas and a gas turning into a liquid?
boiling and condensing
What is the name for a solid turning into a gas?
sublimation
How does heating affect the energy of particles?
the energy of the particles increases
What happens if particles in a solid have enough energy to overcome the forces holding them together?
the particles begin to flow and the solid melts
Define “boiling point”
the temperature at which a liquid turns into a gas
Define “diffusion”
the movement of particles from a high concentration to a low concentration
Define pressure
the force pushing on a particular area
What is the formula to calculate pressure?
pressure = force ¸ area
What is the formula to calculate density?
density = mass ¸ volume
What is a scientific theory?
an idea used to explain events
How are theories proved or disproved?
by collecting evidence
Define a formulation
a mixture designed as a useful product
Give 2 examples of formulations
formula milk and paint
Define “composite”
a material made from two or more different types of material
Give two examples of composites
MDF and fibreglass
What is a polymer?
a very large molecule made from smaller molecules called monomers which are joined together
Give examples of polymers
polyester, polyethene and polystyrene
Other than separating mixtures give another use of chromatography
identifying unknowns
What property of the spots do we compare to identify unknowns
distance travelled compared to the distance travelled by a known substance
What is a contact force?
one that acts through direct contact between objects
What are examples of contact forces?
friction, air resistance, tension, normal contact force, upthrust
What is a resultant force?
a single force that could replace all forces acting on an object
What happens when there is NO resultant force on an object?
It will remain at rest or move with constant speed in straight line.
What happens when there IS a resultant force on an object?
It will accelerate or decelerate.
How can air resistance and friction be reduced?
streamlining (air resistance) and lubrication (friction)
What is pressure?
a measure of the force exerted on an area
What equation links pressure, force and area?
pressure = force divided by area ( P=F/A ). The units of pressure are N/m2, also Pascals).
What is atmospheric pressure?
The pressure caused by the weight of air above a surface.
How does pressure vary with the depth of a fluid?
It increases with depth.
In what direction does pressure in a fluid act?
in all directions
What is the upwards force on an object in a fluid?
upthrust
What type of energy is stored due to interaction of magnetic fields?
magnetic energy
How do magnetic poles interact?
like poles repel - unlike poles attract
What direction are the arrows on magnetic field lines?
north to south (the direction a north pole would move)
What are the four magnetic materials?
iron, steel, cobalt, nickel
What is a permanent magnet?
material that has a permanent magnetic field
What is an induced magnet?
material that has a temporary magnetic field
How does a compass work?
the north end of the compass needle points to geographic north (a magnetic south pole)
