IB MYP - Unit 3. How Do Organisms Sustain Themselves
IB MYP - Unit 3. How Do Organisms Sustain Themselves
IB MYP - Unit 3. How Do Organisms Sustain Themselves
HOW DO
ORGANISMS
SUSTAIN
THEMSELVES?
Systems in living organisms transfer energy and nutrients from the
environment to cells, where they are used to maintain the balance of
life. Diet can be affected by personal and cultural choices.
Factual:
What nutrients do organisms need to survive?
What occurs during the process of digestion?
What occurs during the process of gas exchange?
How are substances transported around an organism?
How do substances move in and out of cells?
What are diffusion, osmosis and active transport?
What is homeostasis?
How do elements essential for life cycle between the environment and
organisms?
Conceptual:
What processes are involved in movement and transport?
Why do the conditions within organisms need to be kept in balance?
Debatable:
Should people use drugs to try to control their weight?
Activity: What do you eat?
The 7 Nutrients
MACRO NUTRIENTS
Large molecules (macromolecules), made of smaller
building blocks (individual units).
CARBOHYDRATES
Elements: carbon, hydrogen and oxygen
Used to create energy
There are 2 types:
Simple (e.g. glucose, fructose, sucrose):
Natural sugar found in fruits and vegetables
Refined sugar found in biscuits, cakes, chocolate
Complex (e.g. starch - macromolecule):
Natural foods such as rice, pasta, bread, nuts, potatoes,
and bananas
Some used straight away, others stored in liver
55% of a balanced diet
3.1 What is meant by a ‘balanced diet’?
PROTEINS EXAMPLES
Animal:
Elements: carbon, hydrogen, Meat
oxygen and nitrogen Poultry
Fish
Essential for the repair of body
Dairy
tissue and building cells
Made of amino acids
Plant:
Animal Protein = 2/3
Pulses
Plant / Vegetable Protein = 1/3 Nuts
(Extra source of energy!) Bread, pasta, rice, potatoes
15% of a balanced diet
3.1 What is meant by a ‘balanced diet’?
LIPIDS EXAMPLES
MICRO NUTRIENTS
3.1 What is meant by a ‘balanced diet’?
VITAMINS
Essential for good health
Vision, skin, red blood cells, healing, bones, teeth, blood
clotting
Water Soluble:
Vitamin C:
Vegetables, fruit (especially citrus)
Fat Soluble:
Vitamin A = Vision
Vegetables, eggs, liver
Vitamin D = Strong Bones
Milk, fish, liver, eggs….and sunshine!!
3.1 What is meant by a ‘balanced diet’?
Vitamins needed as part of balanced diet.
3.1 What is meant by a ‘balanced diet’?
MINERALS
Essential for good health
Need different amounts of each
CALCIUM:
For strong bones and teeth
Milk, cheese, cereals
Lack of calcium causes weak
bones and potentially osteoporosis
IRON:
Helps forms red blood cells….
Red meat, vegetables
Lack of iron causes anaemia
3.1 What is meant by a ‘balanced diet’?
OTHER NUTRIENTS
3.1 What is meant by a ‘balanced diet’?
FIBRES
Examples:
Wholegrain bread and cereal
Fruit and vegetables
3.1 What is meant by a ‘balanced diet’?
WATER
MOUTH
PHARYNX
ESOPHAGUS
LIVER STOMACH
GALL BLADDER
SMALL PANCREAS
INTESTINE LARGE
INTESTINE
RECTUM
ANUS
3.2 What occurs during the process of digestion?
Pleural membranes
3.3 What occurs during the gas exchange?
What is missing?
3.3 What occurs during the gas exchange?
LUNGS
CIRCULATION
PULMONARY PULMONARY
ARTERIES PULMONARY
VEINS
HEART AORTA
VENA CAVA
CIRCULATION
SYSTEMIC
LIVER
HEPATIC VEIN MESENTERIC
ARTERIES
RENAL VEIN STOMACH
RENAL ARTERY
KIDNEYS
LOWER BODY
3.4 What is the circulatory system?
3.4 What is the circulatory system?
There are three main types of blood vessels:
• Arteries carry high pressure blood away from the heart to tissues
that need it.
• Capillaries are very small (< 10 μm diameter) and therefore can
penetrate virtually every tissue in the body. Blood moves slowly
through them under low pressure providing opportunities for the
exchange of substances.
• Veins carry the low pressure blood back to the heart using valves to
ensure blood flows in the correct direction.
A D
C
B
3.4 What is the circulatory system?
It is a double pump the pushes the blood to the lungs and the to the rest
of the body under.
AORTA
VENA CAVA
(superior) PULMONARY
ARTERIES
PULMONARY
ARTERIES
PULMONARY
PULMONARY VEINS
VEINS
LEFT
RIGHT ATRIUM
ATRIUM
VENA CAVA
(inferior)
RIGHT LEFT
VENTRICLE VENTRICLE
3.4 What is the circulatory system?
3.5 What processes are involved in movement and transport?
Diffusion
Random movement of molecules from an area of higher
concentration to the area of lower concentration.
3.5 What processes are involved in movement and transport?
Osmosis
Net movement of water molecules from an area of lower
solute concentration to the area of higher solute
concentration.
Activity: Osmosis
Critical-thinking skills: Use models to explore complex
systems.
Activity: Osmosis
Active transport
Movement of molecules from an area of lower
concentration to the area of higher concentration.
Glucose absorption
Movement of glucose molecules from lumen of small
intestine to epithelial cell and onto blood.
3.6 What is homeostasis?
Temperature
pH
as glycogen
The blood sugar level returns to normal
3.6 What is homeostasis?