A useful resource for Junior Certificate Science-Biology.

1. 27/05/13
Junior Certificate Science BiologyJunior Certificate Science Biology
Humans as OrganismsHumans as Organisms
Theresa Lowry-LehnenTheresa Lowry-Lehnen
RGN, BSc (Hon’s) Specialist Clinical Practitioner (Nursing), Dip Counselling, Dip Adv Psychotherapy,RGN, BSc (Hon’s) Specialist Clinical Practitioner (Nursing), Dip Counselling, Dip Adv Psychotherapy,
BSc (Hon’s) Clinical Science, PGCE (QTS), H. Dip. Ed, MEd, Emotional Intelligence MHS AccrediBSc (Hon’s) Clinical Science, PGCE (QTS), H. Dip. Ed, MEd, Emotional Intelligence MHS Accreditedted

2. 27/05/13
Plant cells vs. Animal cellsPlant cells vs. Animal cells
Both types of cell have these: Only plant cells
have these:
Nucleus
Cytoplasm
Cell wall
Large
vacuole
Cell
membrane
1)
2)
3)
6)
7)
Mitochondria – Energy is
released here by respiration
4)
Chloroplasts

3. 27/05/13
Specialised cellsSpecialised cells
Consider the root hair cell in plants:
It was “suited” to its job of taking in
water and nutrients in 2 ways:
1) It had a large surface area
2) It had a thin cell membrane
The sperm cell is an example of a
specialised ANIMAL cell:
Strong tail for
swimming
Vacuole containing
enzymes

4. 27/05/13
More specialised animal cellsMore specialised animal cells
Red Blood Cell
Carriesoxygen around thebody
No nucleus, largesurfacearea,
packed with haemoglobin
I.D:
Function:
Features:
White blood cell
Egg cell (ovum)
Ciliated
epithelial cell
Nerve cell
(neurone)

5. 27/05/13
Specialised cellsSpecialised cells
Artery and vein
Eye
Compact bone
Blood
Areolar tissue (lung)
Lung
Stratified epithelium (skin)
Columnar epithelium (intestine)
Duodenum (small intestine)
Kidney
Spinal chord
Liver
Ileum (small intestine)
Stomach
Ciliated epithelial (windpipe)
Adipose tissue (fat)
Myelinated nerve
Skin & sebaceous (“oil-producing”)
gland
Testis
Striated (normal) muscle
Non-striated muscle (e.g. stomach)
Cardiac (heart) muscle
Cerebellum (brain)
Ovary
Pancreas

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Cells, tissues, organs and systemsCells, tissues, organs and systems
Basically, all living things are
made up of cells…
A group of CELLS makes up a
TISSUE
A group of TISSUES makes up
an ORGAN
A group of ORGANS makes up a
SYSTEM
A group of SYSTEMS make up an
ORGANISM

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Some systems in the human bodySome systems in the human body
Muscular system Skeletal system
Circulatory
system
Respiratory system
Digestive
system

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DiffusionDiffusion
Diffusion is when something travels from an area of high
concentration to an area of low concentration. For example,
consider the scent from a hamburger…
The “scent particles” from
this hamburger are in high
concentration here:
Eventually they will
“diffuse” out into this area
of low concentration:

9. 27/05/13
DiffusionDiffusion
Cells use diffusion to swap
the oxygen they need for
the carbon dioxide they
no longer want:
Other examples of where diffusion happens in humans:
Alveoli in the lungs Villi in the intestines
Oxygen
diffuses in
Out goes
waste CO2

10. 27/05/13
The digestive systemThe digestive system
The whole point of digestion is to break down our food so
that we can get the bits we need from it…
The main foods
affected are
CARBOHYDRATES –
these are broken down
into GLUCOSE
PROTEINS – these are
broken down into amino
acids
FATS (LIPIDS) –
These are broken down
into fatty acids and
glycerol

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The small intestineThe small intestine
This is where the “small parts” are absorbed into our blood
stream…
Glucose gets
absorbed into
the blood
Everything else
passes into the
large intestine

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EnzymesEnzymes
Enzymes are chemicals produced by the body to help
_______. When they react with food they break it down
into ______ pieces which can then pass into the ______:
Carbohydrase (produced in the mouth,
pancreas and small intestine) breaks
_______ (a carbohydrate) down into
glucose:
Protease (produced in the stomach,
pancreas and small intestine) breaks
_______ down into amino acids:
Lipase (produced in the pancreas and
small intestine) breaks fats (_____)
down into fatty acids and glycerol:
Words – blood, lipids, proteins, digestion, starch, smaller
Bloodstream

13. 27/05/13
The Model IntestineThe Model Intestine
Method:
1) Put some water into two boiling tubes and test the water for starch and
glucose
2) Place the starch into the visking tube bag, add some enzyme and wash the
outside
3) Place some starch WITHOUT enzyme in another visking tube bag
4) Place both visking tubes into the separate boiling tubes and start the stopclock
5) Test the water around the visking tubes for starch and glucose every two
minutes
6) After ten minutes test the water one last time and then test the solutions in
the visking tube bag
1) Why did the starch stay inside the visking tube?
2) What difference did adding the enzyme make? What did it do to
the starch?
3) Where did the glucose go?

14. 27/05/13
Bile and the liverBile and the liver
Bile is a chemical produced in the
liver and stored in the gall
bladder. It has 2 functions:
1) It neutralises stomach acid
and produces alkaline
conditions for enzymes to
work in
2) It emulsifies (“breaks down”
fats:
Fat
globules
Fat
droplets

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BreathingBreathing

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The Respiratory SystemThe Respiratory System
Ribs – to protect
the chest
Bronchioles
Bronchi Trachea – has stiff
rings of cartilage to
prevent it collapsing
Rib muscles –
to raise and
lower the ribs
Lung
Diaphragm –
muscular
sheet
Alveoli (“air sacs”)
– gas exchange
takes place here

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Gas exchangeGas exchange
Alveoli are very good at exchanging gases because…
1) They have a LARGE surface area
2) They have a good blood supply
3) They are moist

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BreathingBreathing

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(Aerobic) Respiration(Aerobic) Respiration
Words – breathing, energy, Mrs Gren, respiration, food
A while ago we learnt about ___ ______. Each of these
life processes needs ENERGY. ___________ is the
process our bodies use to produce this energy:
Glucose + oxygen water + carbon dioxide + ENERGY
The glucose we need comes from ______ and the oxygen
from _________. Water and carbon dioxide are breathed
out. The MAIN product of this equation is _________.

20. 27/05/13
Anaerobic respirationAnaerobic respiration
Unlike aerobic respiration, anaerobic respiration is when
energy is provided WITHOUT needing _________:
This happens when the body can’t provide oxygen quick enough
for __________ respiration to take place.
Anaerobic respiration produces energy much _______ than
aerobic respiration but only produces 1/20th
as much.
Lactic acid is also produced, and this can build up in muscles
causing ______ and an oxygen ______.
This “debt” then needs to be “repaid” by deep breathing to
________ the lactic acid.
Words – debt, oxygen, fatigue, oxidise, aerobic, quicker
Glucose lactic acid + a bit of energy

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Aerobic vs. anaerobic respirationAerobic vs. anaerobic respiration
Similarities
Differences

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The Circulatory systemThe Circulatory system
The circulatory system is responsible
for pumping ______ around the body.
We need blood to be taken around the
body because blood contains ________
and _______. These are needed so
that all the ____ in our bodies can
produce _____ through _________.
The main organs in the circulatory
system are the _____, the lungs and
the kidneys.
Words – energy, heart, blood, glucose,
respiration, oxygen, cells

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The “Double Circulatory” SystemThe “Double Circulatory” System
1. Deoxygenated
blood is pumped
from the heart to
the lungs
3. The oxygenated
blood is then
pumped to the rest
of the body
2. The blood
receives oxygen
and is pumped back
to the heart
4. The oxygen
leaves the blood to
be used for
respiration in the
body and the blood
goes back to the
heart

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The HeartThe Heart
1. Deoxygenated
blood (i.e. blood
without oxygen)
enters through the
vena cava into the
right atrium
2. It’s then
pumped through
the tricuspid valve
into the right
ventricle
3. It’s then pumped
through the semi-lunar
valve up to the lungs
through the pulmonary
artery
4. Oxygenated
blood from the
lungs enters
through the
pulmonary vein into
the left atrium
5. It’s then pumped
through the
bicuspid valve into
the left ventricle
6. It’s then pumped
out of the aorta to
the rest of the
body

25. 27/05/13
Arteries, veins and capillariesArteries, veins and capillaries
Arteries carry high pressure
blood away from the heart.
They have smaller lumen and
no valves.
Veins carry low pressure blood back to the
heart. They have thinner, less elastic walls and
have valves to prevent backflow of blood.
Capillaries have thin walls
(one cell thick) to allow
glucose and oxygen to pass
through. Also used to
connect arteries to veins.
“Lumen”

26. 27/05/13
The four parts of bloodThe four parts of blood
1. RED BLOOD CELLS – contain haemoglobin
and carry ______ around the body. They
have no _______ and a large surface area.
2. PLATELETS – small bits of cells that lie
around waiting for a cut to happen so that
they can ____ (for a scab).
3. WHITE BLOOD CELLS – kill invading
_______ by producing _________ or
engulfing (“eating”) the microbe.
These three are all carried around by the
PLASMA (a straw-coloured liquid). Plasma
transports CO2 and ______ as well as taking
away waste products to the ______.
Words – antibodies, clot, kidneys,
oxygen, nucleus, glucose, microbes.

27. 27/05/13
MicrobesMicrobes
Microbes are micro organisms that can cause diseases. They
can enter the body in a number of ways:
…or other
natural
openings…
They can be
breathed in
through the
mouth or nose
They can enter
through cuts or
bites in the skin

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DiseaseDisease
A disease is any condition where the body isn’t working as it should. This
could be caused by a malfunction in the body (as with diabetes), or it could
be caused by the two types of MICROBE:
VirusesBacteria
•1/1000th
mm big
•Living cells (some are harmless)
•Grow very quickly
•Affected by antibiotics
•Examples: food poisoning,
tetanus, sore throats
•1/1,000,000th
mm big
•Genetic info inside a protein coat
•Not affected by antibiotics
•Release poisons
•Examples: colds, flu, polio,
chicken pox

29. 27/05/13
Microbes: our defence against themMicrobes: our defence against them
Our bodies have four major defence mechanisms against
invading microbes:
If our skin is
cut platelets
seal the wound
by clotting
The breathing
organs produce
mucus to cover the
lining of these
organs and trap the
microbes
The skin acts
as a barrier
Our blood contains
white blood cells

30. 27/05/13
Fighting diseaseFighting disease
If microbes enter our body they need to be
neutralised or killed. This is done by
WHITE BLOOD CELLS:
White blood cells do 3 things:
1) They eat the microbe
2) They produce antibodies to
neutralise the microbe
3) The produce antitoxins to
neutralise the poisons produced
by microbes

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Producing antibodiesProducing antibodies
Step 1: The white blood cell “sees”
the antigen (microbe)
Step 2: The cell produces
antibodies to “fit” the antigen
Step 3: The antibodies fit onto the
antigens and cause them to “clump”
Step 4: The antigens are “eaten”
by the white blood cells
You’re going
down

32. 27/05/13
Fighting diseaseFighting disease
NATURAL IMMUNITY
This is when antibodies are produced by a
person when needed or they are passed on by
the mother during pregnancy.
ARTIFICIAL IMMUNITY
Can be done in two ways:
1) A vaccine with dead microbes is injected
– the body is “tricked” into producing
antibodies ready for the real thing. This
is called PASSIVE IMMUNISATION
2) The antibodies are injected directly into
the body – this is called ACTIVE
IMMUNISATION.