Download 4.6 Rate of reaction

Calculating Rate of Reaction (RoR)
Units for RoR
g/s
cm3/s
Model answer e.g.
Small particles
Larger particles
Large surface
area, therefore
a higher
frequency of
collisions
happen
between
reactants, more
successful
collisions,
meaning a
faster rate of
reaction
Smaller surface
area, therefore a
lower frequency
of collisions
happen between
reactants, there
will be fewer
successful
collisions,
meaning a
slower rate of
reaction.
4.6 Rate of reaction
Key words:
Rate of reaction – the rate at which a reactant is used up, or the
rate at which a product is formed
Collision theory- An explanation of chemical reactions in
terms of reacting particles colliding with enough energy for a
reaction to take place.
Activation energy – The minimum energy needed for a reaction
to start off.
Concentration – The amount of a substance in a given volume
of solution
Catalyst – A substance that speeds up a chemical reaction but
remains chemically unchanged itself at the end of the reaction.
Using tangents
to work out RoR
Enzymes carry out the chemical
reactions in our body; these reactions
are known as METABOLISM.
Digestive enzymes break large food
molecules into small molecules so
they can be absorbed.
Cells are the building blocks of living organisms
Tissue is a group of cells with similar structure and function
Organs are lots of tissues performing specific functions.
Organs are organised into organs systems, which work
together to form organisms.
Plasma: Yellow liquid; transports blood cells, waste CO2 to
lungs, urea from liver to kidneys, digested food.
Red blood cells: Carry oxygen; are biconcave to increase
surface area, haemoglobin which carries oxygen and they
have no nucleus to carry more oxygen.
White blood cell: involved in immunity; fewer in number that
red blood cells, much bigger, nucleus, produce antibodies,
antitoxins and engulf pathogens)
Platelets: small fragments of cells, no nucleus involved in
blood clotting.
Enzyme action is affected by temperature and pH.
Adaptations of the lungs
for gas exchange.
Organisation: Digestive
system, heart and lungs.
enzyme
amylase
Protease
lipase
reaction catalysed
starch → sugars
proteins → amino acids
lipids → fatty acids + glycerol
enzyme
amylase
protease
lipase
where produced
salivary glands, pancreas, small intestine
stomach, pancreas, small intestine
pancreas, small intestine
Adaptations of the
digestive system:
Bile: produced in the liver
and stored in the gall
bladder; emulsifies fat
(smaller droplets) and
neutralises stomach acid.
This increases fat digestion.
LOCK AND KEY MODEL
Heart rate is controlled by group of cells located in the right
atrium that act as a pacemaker. Artificial pacemakers are
electrical machines that correct an irregular heartbeat.
Food test
Food type
Start - Positive result
Iodine
Starch
Orange – blue/black
Biuret test
Protein
Blue – Purple
Benedicts
Some sugars
Blue – red/green orange
Fat
Sudan III
Orange layer
Plants
Roots, stem and leaves form plant organ
system for transport.
Transpiration: The loss of water vapour from the leaves.
Epidermis: covers and protects the leaf.
Palisade mesophyll: contains lots of chloroplasts.
Spongy mesophyll: a few chloroplasts but has air
spaces to increase surface area for diffusion.
Xylem and phloem: transport tissues
Meristem: growing tips in roots and shoots, made up
of rapidly dividing plants cells that grow and
differentiate into different types of cells.
Translocation: Movement of dissolved sugars from the leaves
to the rest of plant.
Phloem tissue transports the sugars. Composed of tubes of
elongated cells. Cell sap can move from one phloem cell to
next through pores in the end walls.
Root hair cells increase surface area to uptake more water by osmosis
and mineral ions by active transport.
Xylem tissue transports water and mineral ions from roots to stems
and leaves. Hollow strengthened tubes to transport water in
transpiration stream.
Stomata in leaves are open and closed by the guard cells to allow
water and carbon dioxide to diffuse in and out.
Transpiration rate increases in high temperatures as molecules move faster in
high temperatures and photosynthesis is increased opening up guard cells.
High humidity reduces transpiration as the is a lower concentration gradient
for osmosis at the stomata.
High air movement increases transpiration by maintaining steep concentration
gradient.
Light intensity increases photosynthesis which opens stomata increasing water
loss.
Cancer : uncontrolled cell division and growth.
Benign tumours: growth of abnormal cells in one area within membrane – DO
NOT SPREAD.
Malignant tumour cells are cancer. Invade tissues and spread to different parts
of the body and form secondary tumours.
There are genetic and lifestyle factors that increase risk.
Other causal factors (lifestyle behaviours that cause certain diseases).
Obesity linked to Type 2 diabetes
Alcohol on liver (liver tissue scarring which do not work as well and liver cancer) and
brain (becomes soft and pulpy and can not longer function properly).
Smoking on lung disease and cancer: Bronchitis, COPD and lung cancer.
Smoking and alcohol during pregnancy. Smoking causes lack of oxygen to foetus
(premature births, low birthweight and even stillbirths). Alcohol can cause miscarriage,
stillbirth, premature births and low birth weight. Babies can have facial deformities,
kidney, liver, heart and learning problems (foetal alcohol syndrome).
Coronary Heart Disease CHD: a non-communicable disease.
CHD formed from a build up of fatty material builds up inside of coronary
arteries, narrowing them. This reduces oxygen to the heart muscle – lead to
heart attack or death.
Treatment of CHD
Stents
Statins
Given to reduce the cholesterol which slows down
fatty deposits.
artery.
Transplants
Heart bypass surgery can take place using veins f
from other parts of the body to replace the blocked
A donor heart or heart and lungs can be transplanted.
An artificial heart can be used to keep patients
alive whilst waiting for a transplant or allow the
heart to rest.
Faulty heart valves: In some people valves become faulty, preventing the
valve opening or it may develop a leak. People become breathless or may
die. They can replaced using biological or mechanical valves.
Health: state of physical and mental well-being.
Disease, both communicable and non-communicable cause ill health.
Factors such as diet, stress, and life situations have an effect on health.
Different types of disease may interact:
• Defects in immune system means someone more likely to suffer from
infectious disease.
• Viruses living in cells can trigger some cancer.
• Immune reactions first caused by pathogens can trigger allergies.
• Severe physical ill health can lead to depression and other mental
illness.
Cardiovascular disease:
Diet: Too much fat (needed for energy and organ protection) can cause
obesity and heart disease.
Exercise: Too little exercise can cause obesity and heart disease.
Smoking: Can lead to arteries narrowing, clot formation, increase in blood
pressure can cause heart disease.
Organisation revision questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Describe the journey of food
through the digestive system.
What are the role of enzymes in
our body? What is this called? 15.
How do enzymes speed up the
16.
process of digestion
What is the name of the model
given to explain how enzymes
work?
Describe how amylase breaks 17.
down starch and where it does 18.
it.
What is the effect of
temperature on how enzymes
19.
work?
Name the four main chambers
of the heart.
Describe how heart rate is
regulated. What can be given to 20.
regulate an irregular heart beat?
21.
How are arteries and veins
adapted to do their job?
Give three ways the lungs are 22.
adapted to have efficient gas
exchange.
a. Name the two cells carried in 23.
the blood.
b. State their job (function)
24.
c. How are they adapted to
25.
carry out this function?
26.
Why is coronary heart disease 27.
described as noncommunicable?
Give three ways coronary heart 28.
disease can be treated
Describe the advantages and
29.
disadvantages of using a stent to
improve blood flow to the
heart.
•
Give a definition of health.
Explain how the following effect
the risk of cardiovascular
disease: Smoking, Exercise and •
Diet
Name the diseases that the
following lifestyle behaviours •
are CAUSAL factors for
(including during pregnancy):
Smoking, Alcohol
What is cancer?
•
Describe a malignant tumour
and it’s effect on the body.
Look at the graph; what is the
relationship between obesity
and Type 2 diabetes
Explain the role of the palisade
and spongy mesophyll layer in
the leaf
What is translocation?
Where does it take place?
What is transpiration?
What organs in the plant move
water from the root to the
leaves?
How are these organs adapted
to do this?
How do the following factors
affect the rate of transpiration?
High temperatures:
Increased light intensity:
High humidity:
Increased air movement (windy):
What are the properties of reflection, refraction and diffraction?
Task 1: Copy and fill out the table below
Definition
Reflection
Refraction
Diffraction
Properties
Examples
e.g. the law of reflection states that
…
The change in
_________ of
________ when they
travel across a
b_______
S_______ pool
appearing
s_______than it
is
• The n_______ a gap is, the
g_________ the diffraction
• The w_______ a gap is, the
_________ the diffraction