Science Notes 24
Notes
(Feed the World)
Outcomes:
● Meaning of Undernourished:
○ Insufficient calorie intake
○ Lack of essential nutrients
○ Adverse health effects
● Countries Most in Need of Food:
○ South Sudan
○ Yemen
○ Ethiopia
○ Madagascar
○ Afghanistan
● Main Causes of Hunger:
○ Conflict and instability
○ Climate change and natural disasters
○ Economic factors and poverty
○ Poor infrastructure and food distribution
● Ways to Minimize Food Waste:
○ Educate consumers on portion sizes
○ Implement better supply chain practices
○ Utilize food recovery networks
○ Encourage composting and recycling of food scraps
● Body’s Requirement for Energy, Nutrients, and Water:
○ All organisms need energy to grow and function; we get this from food.
○ Balanced diet includes various biological molecules (carbohydrates, proteins, lipids, vitamins, minerals, dietary fiber, and water).
● Roles and Sources of Nutrients:
○ Four Main Nutrients:
■ Carbohydrates (energy)
■ Proteins (growth and repair)
■ Fats/Oils (insulation & energy)
■ Vitamins (healthy gums)
○ Food Categorization:
■ Complex Carbohydrates → Simple sugars, glucose
■ Complex Proteins → Simple amino acids
■ Complex Fats → Simple fatty acids, glycerol
● Impact of Excess Sugar:
○ Threats of cardiovascular disease
○ Obesity
○ Diabetes
● Chemicals Found in Food:
○ Water
○ Carbohydrates
○ Proteins
○ Fats
○ Vitamins
○ Minerals
○ Minerals: Inorganic
○ Vitamins: Organic
● Common Characteristics of Non-metals/Metalloids:
○ Non-metals: Poor conductors, low density, brittle
○ Metalloids: Semiconductors, properties of both metals and non-metals
● Identifying Elements in the Periodic Table:
○ Non-metals: H, C, N, O, P, S, noble gases
○ Metalloids: B, Si, Ge, As, Sb, Te
● First 20 Elements of the Periodic Table:
○ H
○ He
○ Li
○ Be
○ B
○ C
○ N
○ O
○ F
○ Ne
○ Na
○ Mg
○ Al
○ Si
○ P
○ S
○ Cl
○ Ar
○ K
○ Ca
● Arrangement of Elements by Proton Numbers:
○ Periodic table organized by increasing atomic (proton) number
● Roots:
○ Anchor plant
○ Absorb water and nutrients
○ Store energy
● Stems:
○ Xylem: Transports water/minerals from roots to leaves
○ Phloem: Transports sugars from leaves to other parts
● Leaves:
○ Main site for photosynthesis
○ Contain stomata for gas exchange (CO₂ in, O₂ out)
● Flowers:
○ Reproductive structures
○ Facilitate pollination and seed formation
● Common Requirements:
○ Water
○ Nutrients
○ Energy for growth and survival
○ Cellular respiration processes
● Photosynthesis:
○ Converts light energy into chemical energy (glucose)
○ Equation: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
● Respiration:
○ Breaks down glucose to release energy
○ Equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)
● Increasing Global Food Production:
○ Genetic Engineering: Develop pest/disease-resistant crops
○ Sustainable Agriculture: Maintain soil health, reduce environmental impact
○ Vertical Farming: Maximize urban space for food production
○ Improved Irrigation Techniques: Enhance water efficiency in arid regions
Fun Park Physics
● Review of Energy Types:
○ Different forms of energy: light, heat, mechanical, gravitational, electrical, sound, chemical and kinetic energy.
● Sound and Light:
○ Sound is produced by roller coasters (e.g., whooshing sounds).
○ Lights are used on many rides for safety and effect.
● Sound Waves:
○ Created by an object vibrations and produces sound waves
● Light Waves:
○ Forms of moving energy made of particles.
● Kinetic and Potential Energy:
○ Objects possess energy due to motion (kinetic) or position (potential).
● Conservation of Energy:
○ The law of conservation of energy states that energy cannot be created or destroyed, only transformed.
● Roller Coaster Dynamics:
○ Roller coasters convert potential energy (at the top of a hill) into kinetic energy (as they descend).
● Calculations:
○ Weight = mass * g
○ Give answer in joules
○ Kinetic energy of an object depends on its speed and mass
○ Ke = 1/2m or v squared
○ Ke= 1/2 mass velocity squared
○
○ Potential Energy and GPE: mgh (mass × acceleration due to gravity × height)
○
○ NESSECASRY key for finding PE & GPE:
○
○ GPE =mh (mass * height)
○ = mgh (mass has to be in kg for the formula to work)
○ = h (always has to be in metres)
○
○ To find mass: GPE/(g*h)
○
● Definition of Force:
○ A force is a push, pull, or twist applied to one object from another.
○ Measured in Newtons.
● Effects of Forces:
○ Forces can start, speed up, change direction, change shape, and stop objects.
○ A force affects the object to which it is applied.
● Identifying Forces:
○ Look for a push or pull as an indicator of force.
● Types of Forces:
○ Contact Forces: Require one object to touch another (e.g., cricket ball and bat).
○ Non-contact Forces: Act without the objects touching (e.g., gravity).
● Gravitational Force:
○ Keeps you bound to the floor and the surface of the Earth.
● Magnetic Force:
○ The force of a magnet pulling on some metallic objects; can attract or repel magnets.
● Electrostatic Force:
○ The force applied between electrically charged objects (e.g., causing hair to stand up when you rub a balloon against it).
● Description of Friction:
○ Friction is a force that resists or prevents the motion of two surfaces in contact.
● Friction's Effects:
○ Heat, wear, and tear on surfaces.
● Reducing Friction:
○ Using lubricants like grease and oil.
○ Streamlining objects or vehicles.
○ Using rollers or ball bearings.
● Surface Characteristics:
○ Smooth surfaces provide less friction than rough surfaces.
○ Larger contact areas between surfaces result in more friction.
● Helpful and Harmful Aspects:
○ Friction can be both beneficial (e.g., allowing for walking) and detrimental (e.g., causing wear).
● Definition of Gravity:
○ Gravity is a non-contact force that keeps objects bound to the Earth.
● Field Concept:
○ Even if youre not touching the earth, it will still you pull you down by its gravitational field.
● Gravity in Roller Coasters:
○ In descents and loops.
● Revision from Y7:
○ All objects exert a force of gravity on each other in the universe.
● Unbalanced Forces:
○ When there is a higher force being applied on one side than the other, causing the object or person to move, that means the net force will not be 0 newtons.
○ Example: When a person kicks a ball, the amount of force they exert, is more superior to any other forces that effect the stopping of the ball, friction, air resistnace.
● Mass vs. Weight:
○ Mass is the total amount of matter in an object, where as weight is the force of gravity on an object.
○ Mass Formula: w/g
○ Weight Formula: m*g
■ Mass (m) is measured in kilograms (kg).
■ Gravity (g) is approximately 9.8 m/s
● Example weight calculation:
○ For a mass of 4.5 kg:
■ Weight = 4.5 kg×9.8 m/s
■ = 44.1 N
● Gravity Ratios:
○ To calculate the ratio of gravity on one planet relative to another:
■ = gravity on the planet you are calculating/gravity on the other planet
e.g., Acceleration due to gravity on earth is 9.8m/s squared. How much would a person weigh on Venus, where the acceleration due to gravity is 8.9m/squared.
Ratio= 8.9/9.8=0.9082
= 0.91
Therefore the gravity on Venus is 91% of the stregnth of that on Earth.
● Charges:
○ Electron: Negative charge.
○ Proton: Positive charge.
○ Neutron: Neutral charge.
● Location of Charges:
○ Electrons are found at the rim of the atom (or cell).
○ Protons and neutrons are located in the nucleus of the atom.
● Charging Process:
○ Electrons can be ‘rubbed off’ one material and transferred to another.
○ The material that gains electrons becomes negatively charged.
○ The material that loses electrons is left with a positive charge.
● Everyday Situations:
○ When clothing is rubbed on wearers skin.
● Behaviour of Charges:
○ Like charges repel and unlike charges attract.
● Static Electricity in Roller Coasters:
○ Roller coaster wheels create static electricity through friction against tracks.
○ Grounding straps and lightning rods prevent charge build-up.
● Magnetic Systems:
○ Many roller coasters use magnetic launch and braking systems.
● Magnetic Poles:
○ When two magnetic poles are brought together they exert a force on each other.
● Magnets and Electromagnets:
○ A compass uses a magnetic needle to point out north and south.
● Measuring Force:
○ The instrument used to measure force is a force meter or spring balance.
○ Force is measured in newtons (N).
● Net Force:
○ The net force is the result of subtracting opposing forces; add forces only when they are in the same direction.
● Balanced and Unbalanced Forces:
○ Forces always occur in pairs.
○ Balanced Forces:
■ Forces that cancel each other out (e.g., tug of war with equal teams).
■ The net force is 0 newtons.
○ Unbalanced Forces:
■ One side applies more force than the other, causing movement (e.g., tug of war where one team has more players).
■ The net force is not 0 newtons.
● Air Resistance:
○ As an object's speed increases, air resistance (a form of friction) also increases due to contact with more air particles.
● Terminal Velocity:
○ The constant speed reached when the weight force and air resistance are balanced.
Emergency
● Used to coordinate and organise cells in our body.
● (Smallest) Cells, Tissues, Organs, System, Multicellular Organisms. (largest)
● Complex processes to be controlled.
● Many form a tissue.
● All cells in a tissue are the same type.
● e.g., muscle cells group together to form muscle tissues.
Epithelial Tissue
Connective Tissue
Muscle Tissue
Nervous Tissue
● Made of functionally related tissues.
● Tissues grouped together to make a specific function.
● e.g., your stomach (mouth, oesophagus, small/large intestines).
● These organs make up the digestive system.
● Organism = many organ systems working together.
Cells need energy sources, matter including nutrients, and wastes removed, in order to survive.
Acronym: (MEWIN)
● Matter
● Energy Sources
● Water
● Waste Removal
● Ions
● Nutrients
● Light energy
● Chemical energy
Includes carbon dioxide, oxygen, carbohydrates, amino acids, fatty acids, glycerol, nucleic acids, ions, and water.
● Matter makes nucleic acids like DNA or RNA.
○ Amino Acids = Protein
○ Fatty acids & glycerol = lipids
Include carbon dioxide, urea, ammonia, uric acid, water, ions, and metabolic heat.
● Building blocks to make organelles in a cell.
● Protein Breakdowns --> Ammonia and Uric acid.
Cells have various mechanisms to achieve this, such as osmosis, diffusion, active transport, and cytosis via the cell membrane.
● Water --> Osmosis
● CO2, Photosynthesis, Oxygen --> Diffusion
● The goal of photosynthesis is to produce glucose to undergo respiration.
What: Is a process in a plant/body that’s purpose is to produce energy, in a form that an organism can use.
Without respiration occurring in a cell, the cell will die.
Where: Cellular respiration takes place in every cell of a body, in the cytoplasm and/or mitochondria.
When: Occurs throughout day and night.
Why: It produces energy that is needed for the body to function properly.
How: Photosynthesis = glucose ---> respiration.
Formula: glucose + oxygen = CO2 + Water + Energy
● Main purpose: Body's delivery system.
● Provides nutrients to organs and cells.
● Rubbish collector.
● Deliver important signals.
Happens when there is a decreased blood flow to the brain. When the brain detects lack of oxygen, it makes you lose consciousness, leaving muscles floppy. Once on the floor, it helps your blood flow as it doesn’t have to fight gravity to reach your brain.
● Takes oxygen from your lungs and digested nutrients from your gut into the blood.
● Removes waste products from cells (CO2, chemical urea) and takes them to the organs that excrete.
● If waste weren't removed, it wouldn’t be able to work at its best.
● Blood transports vital nutrients (oxygen) so you can grow, produce energy, and do work.
● e.g., CO2 goes to your lungs to be exhaled out; urea goes to kidneys to be processed into urine.
● Body's internal signals, like thirst or hunger, are caused by messenger molecules called hormones.
● Hormones produced by many different organs travel through the blood to other organs.
We need oxygen for respiration.
● Motor powering movement of blood.
● Made of muscle.
● Pumps continuously.
● Natural pacemaker.
● Spread out from the heart.
● Deliver blood to organs and tissues.
● Large vessels (arteries).
● Blood reaches individual cells, dividing and shrinking to form a network of capillaries.
● Capillaries rejoin into large veins.
● Fluid part (plasma).
● Solid part (blood cells).
● Delivers nutrients and oxygen to all cells in the body.
● Fluid part carries dissolved nutrients, hormones, and waste.
● Oxygen only a little bit is dissolved in the plasma, carried by red blood cells.
The heart is essential; it keeps our blood mobile and provides our cells with oxygen and nutrients to survive.
The heart is the motor of the circulatory system. The heart muscle contracts and pumps deoxygenated blood directly into the lungs, where it becomes oxygenated.
● Muscle that acts like a pump, size of your fist, located in the left/middle of your chest.
● It is a natural pacemaker called the sinoatrial node, located in the right atrium.
● Sinoatrial node controls the heart by sending electrical signals, making the heart contract and pump blood.
● Deoxygenated: low in oxygen.
● Oxygenated: high in oxygen.
● Atria have thin walls, while the ventricles have thick, muscular walls.
● The left atrium and the right atrium are separated by a wall called the atrial septum, which is as thick and muscular as the ventricles.
● The left and the right ventricle are separated by the ventricular septum, which is as thick and muscular as themselves.
● The ventricular septum doesn’t have valves.
When viewing the heart, left = right | right = left.
● Superior Vena Cava: carries blood from your head, neck, and upper limbs.
● Inferior Vena Cava: carries blood from the rest of your body.
Deoxygenated blood in our capillaries enters the veins.
When the right atrium contracts, blood is pushed into the right ventricle. The right ventricle contracts, sending blood into the pulmonary artery. The left ventricle contracts and ejects blood into the largest artery in our body, the aorta. The aorta then splits into small arteries turning into capillaries. These blood vessels supply our cells with oxygenated blood.
● Left + Right = receiving chambers.
● Blood enters the atria of the heart through the veins.
● It comes through the pulmonary veins coming from the lungs to the left atrium.
● After being received by the atria, it gets pushed into the ventricle on the same side (left atrium - left ventricle).
● The atrium is separated from the ventricle by a valve; they close as the ventricle contracts to prevent blood from flowing backward.
● When the ventricles contract, they pump blood into your arteries, which will reach your body.
Takes 1 minute.
● Right side: delivers deoxygenated blood to the lungs to be oxygenated.
● Left side: delivers oxygenated blood to the rest of the body for cells.
When feeling tired, it's because your heart and lungs have to work harder to circulate blood and air.
● Veins carry blood towards the heart.
● Arteries carry blood away from the heart.
● Blood’s job is to take oxygen to every part of your body.
● Lungs bring air.
● Blood is the delivery service.
● CO2 is a waste product.
● Heart is the size of a fist.
● Blood flow will take you to the 4 chambers in the heart: Right atrium, Left atrium, Right ventricle, Pulmonary valve.
● Arteries carry blood away from the heart.
● Veins carry blood into the heart.
Functions of the different parts of hearts:
● Superior vena cava - carries blood from the upper body TO the heart
● Inferior vena cava - carries blood from lower body TO the heart
● Pulmonary Veins - transfer oxygenated blood from the lungs to the left side of heart
● Pulmonary artery - carries deoxygenated blood to your lungs
● Valves - prevent the backward flow of blood
● Aorta - carries oxygen-rich blood away from the heart to the rest of the body.
● Atrium - It helps blood flow smoothly back to the heart while the heart is pumping
● Ventricles - The ventricles pump blood out of the heart: the right ventricle sends blood to the lungs, and the left ventricle sends blood to the rest of the body.
● Capillaries - tiny blood vessels have thin walls. Oxygen and nutrients from the blood can move through the walls and get into organs and tissues. Capillaries are where oxygen and nutrients are exchanged for carbon dioxide and waste.
● Arteries - carry oxygen rich blood to the rest of your body
‘
Importance of different parts of hearts:
● Superior Vena Cava - without this, there would be no circulation of blood, causing organ failure
● Inferior Vena Cava - Without the inferior vena cava, the body would struggle to return deoxygenated blood from the lower half, leading to blood accumulation, swelling, reduced oxygen supply, and potentially life-threatening organ dysfunction.
● Pulmonary Veins - oxygenated blood from the lungs wouldn't return to the heart, leading to severe oxygen deprivation in the body, respiratory failure, and ultimately life-threatening
● Pulmovary Artery - Without the pulmonary artery, deoxygenated blood would be unable to flow from the heart to the lungs for oxygenation, resulting in a buildup of carbon dioxide and severe oxygen deprivation in the body.
● Valves - Without valves, blood would flow backward and fail to circulate efficiently, leading to reduced blood pressure, inadequate organ perfusion, and potentially life-threatening circulatory issues.
● Aorta - Without the aorta, oxygenated blood would be unable to exit the heart to supply the body, leading to rapid organ failure and death due to lack of essential nutrients and oxygen.
● Atrium - Without atria, the heart would struggle to collect and efficiently pump blood into the ventricles, leading to impaired circulation and inadequate blood flow to the body and lungs.
● Ventricles - Without ventricles, the heart would be unable to pump blood effectively to the lungs and the rest of the body, resulting in immediate circulatory failure and death.
● Capillaries - Without capillaries, the exchange of oxygen, nutrients, and waste products between blood and tissues would be impossible, leading to severe tissue damage and organ failure.
● Arteries - Without arteries, oxygenated blood could not be transported from the heart to the body's tissues, resulting in immediate and life-threatening oxygen deprivation.
Notes
(Feed the World)
Outcomes:
● Meaning of Undernourished:
○ Insufficient calorie intake
○ Lack of essential nutrients
○ Adverse health effects
● Countries Most in Need of Food:
○ South Sudan
○ Yemen
○ Ethiopia
○ Madagascar
○ Afghanistan
● Main Causes of Hunger:
○ Conflict and instability
○ Climate change and natural disasters
○ Economic factors and poverty
○ Poor infrastructure and food distribution
● Ways to Minimize Food Waste:
○ Educate consumers on portion sizes
○ Implement better supply chain practices
○ Utilize food recovery networks
○ Encourage composting and recycling of food scraps
● Body’s Requirement for Energy, Nutrients, and Water:
○ All organisms need energy to grow and function; we get this from food.
○ Balanced diet includes various biological molecules (carbohydrates, proteins, lipids, vitamins, minerals, dietary fiber, and water).
● Roles and Sources of Nutrients:
○ Four Main Nutrients:
■ Carbohydrates (energy)
■ Proteins (growth and repair)
■ Fats/Oils (insulation & energy)
■ Vitamins (healthy gums)
○ Food Categorization:
■ Complex Carbohydrates → Simple sugars, glucose
■ Complex Proteins → Simple amino acids
■ Complex Fats → Simple fatty acids, glycerol
● Impact of Excess Sugar:
○ Threats of cardiovascular disease
○ Obesity
○ Diabetes
● Chemicals Found in Food:
○ Water
○ Carbohydrates
○ Proteins
○ Fats
○ Vitamins
○ Minerals
○ Minerals: Inorganic
○ Vitamins: Organic
● Common Characteristics of Non-metals/Metalloids:
○ Non-metals: Poor conductors, low density, brittle
○ Metalloids: Semiconductors, properties of both metals and non-metals
● Identifying Elements in the Periodic Table:
○ Non-metals: H, C, N, O, P, S, noble gases
○ Metalloids: B, Si, Ge, As, Sb, Te
● First 20 Elements of the Periodic Table:
○ H
○ He
○ Li
○ Be
○ B
○ C
○ N
○ O
○ F
○ Ne
○ Na
○ Mg
○ Al
○ Si
○ P
○ S
○ Cl
○ Ar
○ K
○ Ca
● Arrangement of Elements by Proton Numbers:
○ Periodic table organized by increasing atomic (proton) number
● Roots:
○ Anchor plant
○ Absorb water and nutrients
○ Store energy
● Stems:
○ Xylem: Transports water/minerals from roots to leaves
○ Phloem: Transports sugars from leaves to other parts
● Leaves:
○ Main site for photosynthesis
○ Contain stomata for gas exchange (CO₂ in, O₂ out)
● Flowers:
○ Reproductive structures
○ Facilitate pollination and seed formation
● Common Requirements:
○ Water
○ Nutrients
○ Energy for growth and survival
○ Cellular respiration processes
● Photosynthesis:
○ Converts light energy into chemical energy (glucose)
○ Equation: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
● Respiration:
○ Breaks down glucose to release energy
○ Equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)
● Increasing Global Food Production:
○ Genetic Engineering: Develop pest/disease-resistant crops
○ Sustainable Agriculture: Maintain soil health, reduce environmental impact
○ Vertical Farming: Maximize urban space for food production
○ Improved Irrigation Techniques: Enhance water efficiency in arid regions
Fun Park Physics
● Review of Energy Types:
○ Different forms of energy: light, heat, mechanical, gravitational, electrical, sound, chemical and kinetic energy.
● Sound and Light:
○ Sound is produced by roller coasters (e.g., whooshing sounds).
○ Lights are used on many rides for safety and effect.
● Sound Waves:
○ Created by an object vibrations and produces sound waves
● Light Waves:
○ Forms of moving energy made of particles.
● Kinetic and Potential Energy:
○ Objects possess energy due to motion (kinetic) or position (potential).
● Conservation of Energy:
○ The law of conservation of energy states that energy cannot be created or destroyed, only transformed.
● Roller Coaster Dynamics:
○ Roller coasters convert potential energy (at the top of a hill) into kinetic energy (as they descend).
● Calculations:
○ Weight = mass * g
○ Give answer in joules
○ Kinetic energy of an object depends on its speed and mass
○ Ke = 1/2m or v squared
○ Ke= 1/2 mass velocity squared
○
○ Potential Energy and GPE: mgh (mass × acceleration due to gravity × height)
○
○ NESSECASRY key for finding PE & GPE:
○
○ GPE =mh (mass * height)
○ = mgh (mass has to be in kg for the formula to work)
○ = h (always has to be in metres)
○
○ To find mass: GPE/(g*h)
○
● Definition of Force:
○ A force is a push, pull, or twist applied to one object from another.
○ Measured in Newtons.
● Effects of Forces:
○ Forces can start, speed up, change direction, change shape, and stop objects.
○ A force affects the object to which it is applied.
● Identifying Forces:
○ Look for a push or pull as an indicator of force.
● Types of Forces:
○ Contact Forces: Require one object to touch another (e.g., cricket ball and bat).
○ Non-contact Forces: Act without the objects touching (e.g., gravity).
● Gravitational Force:
○ Keeps you bound to the floor and the surface of the Earth.
● Magnetic Force:
○ The force of a magnet pulling on some metallic objects; can attract or repel magnets.
● Electrostatic Force:
○ The force applied between electrically charged objects (e.g., causing hair to stand up when you rub a balloon against it).
● Description of Friction:
○ Friction is a force that resists or prevents the motion of two surfaces in contact.
● Friction's Effects:
○ Heat, wear, and tear on surfaces.
● Reducing Friction:
○ Using lubricants like grease and oil.
○ Streamlining objects or vehicles.
○ Using rollers or ball bearings.
● Surface Characteristics:
○ Smooth surfaces provide less friction than rough surfaces.
○ Larger contact areas between surfaces result in more friction.
● Helpful and Harmful Aspects:
○ Friction can be both beneficial (e.g., allowing for walking) and detrimental (e.g., causing wear).
● Definition of Gravity:
○ Gravity is a non-contact force that keeps objects bound to the Earth.
● Field Concept:
○ Even if youre not touching the earth, it will still you pull you down by its gravitational field.
● Gravity in Roller Coasters:
○ In descents and loops.
● Revision from Y7:
○ All objects exert a force of gravity on each other in the universe.
● Unbalanced Forces:
○ When there is a higher force being applied on one side than the other, causing the object or person to move, that means the net force will not be 0 newtons.
○ Example: When a person kicks a ball, the amount of force they exert, is more superior to any other forces that effect the stopping of the ball, friction, air resistnace.
● Mass vs. Weight:
○ Mass is the total amount of matter in an object, where as weight is the force of gravity on an object.
○ Mass Formula: w/g
○ Weight Formula: m*g
■ Mass (m) is measured in kilograms (kg).
■ Gravity (g) is approximately 9.8 m/s
● Example weight calculation:
○ For a mass of 4.5 kg:
■ Weight = 4.5 kg×9.8 m/s
■ = 44.1 N
● Gravity Ratios:
○ To calculate the ratio of gravity on one planet relative to another:
■ = gravity on the planet you are calculating/gravity on the other planet
e.g., Acceleration due to gravity on earth is 9.8m/s squared. How much would a person weigh on Venus, where the acceleration due to gravity is 8.9m/squared.
Ratio= 8.9/9.8=0.9082
= 0.91
Therefore the gravity on Venus is 91% of the stregnth of that on Earth.
● Charges:
○ Electron: Negative charge.
○ Proton: Positive charge.
○ Neutron: Neutral charge.
● Location of Charges:
○ Electrons are found at the rim of the atom (or cell).
○ Protons and neutrons are located in the nucleus of the atom.
● Charging Process:
○ Electrons can be ‘rubbed off’ one material and transferred to another.
○ The material that gains electrons becomes negatively charged.
○ The material that loses electrons is left with a positive charge.
● Everyday Situations:
○ When clothing is rubbed on wearers skin.
● Behaviour of Charges:
○ Like charges repel and unlike charges attract.
● Static Electricity in Roller Coasters:
○ Roller coaster wheels create static electricity through friction against tracks.
○ Grounding straps and lightning rods prevent charge build-up.
● Magnetic Systems:
○ Many roller coasters use magnetic launch and braking systems.
● Magnetic Poles:
○ When two magnetic poles are brought together they exert a force on each other.
● Magnets and Electromagnets:
○ A compass uses a magnetic needle to point out north and south.
● Measuring Force:
○ The instrument used to measure force is a force meter or spring balance.
○ Force is measured in newtons (N).
● Net Force:
○ The net force is the result of subtracting opposing forces; add forces only when they are in the same direction.
● Balanced and Unbalanced Forces:
○ Forces always occur in pairs.
○ Balanced Forces:
■ Forces that cancel each other out (e.g., tug of war with equal teams).
■ The net force is 0 newtons.
○ Unbalanced Forces:
■ One side applies more force than the other, causing movement (e.g., tug of war where one team has more players).
■ The net force is not 0 newtons.
● Air Resistance:
○ As an object's speed increases, air resistance (a form of friction) also increases due to contact with more air particles.
● Terminal Velocity:
○ The constant speed reached when the weight force and air resistance are balanced.
Emergency
● Used to coordinate and organise cells in our body.
● (Smallest) Cells, Tissues, Organs, System, Multicellular Organisms. (largest)
● Complex processes to be controlled.
● Many form a tissue.
● All cells in a tissue are the same type.
● e.g., muscle cells group together to form muscle tissues.
Epithelial Tissue
Connective Tissue
Muscle Tissue
Nervous Tissue
● Made of functionally related tissues.
● Tissues grouped together to make a specific function.
● e.g., your stomach (mouth, oesophagus, small/large intestines).
● These organs make up the digestive system.
● Organism = many organ systems working together.
Cells need energy sources, matter including nutrients, and wastes removed, in order to survive.
Acronym: (MEWIN)
● Matter
● Energy Sources
● Water
● Waste Removal
● Ions
● Nutrients
● Light energy
● Chemical energy
Includes carbon dioxide, oxygen, carbohydrates, amino acids, fatty acids, glycerol, nucleic acids, ions, and water.
● Matter makes nucleic acids like DNA or RNA.
○ Amino Acids = Protein
○ Fatty acids & glycerol = lipids
Include carbon dioxide, urea, ammonia, uric acid, water, ions, and metabolic heat.
● Building blocks to make organelles in a cell.
● Protein Breakdowns --> Ammonia and Uric acid.
Cells have various mechanisms to achieve this, such as osmosis, diffusion, active transport, and cytosis via the cell membrane.
● Water --> Osmosis
● CO2, Photosynthesis, Oxygen --> Diffusion
● The goal of photosynthesis is to produce glucose to undergo respiration.
What: Is a process in a plant/body that’s purpose is to produce energy, in a form that an organism can use.
Without respiration occurring in a cell, the cell will die.
Where: Cellular respiration takes place in every cell of a body, in the cytoplasm and/or mitochondria.
When: Occurs throughout day and night.
Why: It produces energy that is needed for the body to function properly.
How: Photosynthesis = glucose ---> respiration.
Formula: glucose + oxygen = CO2 + Water + Energy
● Main purpose: Body's delivery system.
● Provides nutrients to organs and cells.
● Rubbish collector.
● Deliver important signals.
Happens when there is a decreased blood flow to the brain. When the brain detects lack of oxygen, it makes you lose consciousness, leaving muscles floppy. Once on the floor, it helps your blood flow as it doesn’t have to fight gravity to reach your brain.
● Takes oxygen from your lungs and digested nutrients from your gut into the blood.
● Removes waste products from cells (CO2, chemical urea) and takes them to the organs that excrete.
● If waste weren't removed, it wouldn’t be able to work at its best.
● Blood transports vital nutrients (oxygen) so you can grow, produce energy, and do work.
● e.g., CO2 goes to your lungs to be exhaled out; urea goes to kidneys to be processed into urine.
● Body's internal signals, like thirst or hunger, are caused by messenger molecules called hormones.
● Hormones produced by many different organs travel through the blood to other organs.
We need oxygen for respiration.
● Motor powering movement of blood.
● Made of muscle.
● Pumps continuously.
● Natural pacemaker.
● Spread out from the heart.
● Deliver blood to organs and tissues.
● Large vessels (arteries).
● Blood reaches individual cells, dividing and shrinking to form a network of capillaries.
● Capillaries rejoin into large veins.
● Fluid part (plasma).
● Solid part (blood cells).
● Delivers nutrients and oxygen to all cells in the body.
● Fluid part carries dissolved nutrients, hormones, and waste.
● Oxygen only a little bit is dissolved in the plasma, carried by red blood cells.
The heart is essential; it keeps our blood mobile and provides our cells with oxygen and nutrients to survive.
The heart is the motor of the circulatory system. The heart muscle contracts and pumps deoxygenated blood directly into the lungs, where it becomes oxygenated.
● Muscle that acts like a pump, size of your fist, located in the left/middle of your chest.
● It is a natural pacemaker called the sinoatrial node, located in the right atrium.
● Sinoatrial node controls the heart by sending electrical signals, making the heart contract and pump blood.
● Deoxygenated: low in oxygen.
● Oxygenated: high in oxygen.
● Atria have thin walls, while the ventricles have thick, muscular walls.
● The left atrium and the right atrium are separated by a wall called the atrial septum, which is as thick and muscular as the ventricles.
● The left and the right ventricle are separated by the ventricular septum, which is as thick and muscular as themselves.
● The ventricular septum doesn’t have valves.
When viewing the heart, left = right | right = left.
● Superior Vena Cava: carries blood from your head, neck, and upper limbs.
● Inferior Vena Cava: carries blood from the rest of your body.
Deoxygenated blood in our capillaries enters the veins.
When the right atrium contracts, blood is pushed into the right ventricle. The right ventricle contracts, sending blood into the pulmonary artery. The left ventricle contracts and ejects blood into the largest artery in our body, the aorta. The aorta then splits into small arteries turning into capillaries. These blood vessels supply our cells with oxygenated blood.
● Left + Right = receiving chambers.
● Blood enters the atria of the heart through the veins.
● It comes through the pulmonary veins coming from the lungs to the left atrium.
● After being received by the atria, it gets pushed into the ventricle on the same side (left atrium - left ventricle).
● The atrium is separated from the ventricle by a valve; they close as the ventricle contracts to prevent blood from flowing backward.
● When the ventricles contract, they pump blood into your arteries, which will reach your body.
Takes 1 minute.
● Right side: delivers deoxygenated blood to the lungs to be oxygenated.
● Left side: delivers oxygenated blood to the rest of the body for cells.
When feeling tired, it's because your heart and lungs have to work harder to circulate blood and air.
● Veins carry blood towards the heart.
● Arteries carry blood away from the heart.
● Blood’s job is to take oxygen to every part of your body.
● Lungs bring air.
● Blood is the delivery service.
● CO2 is a waste product.
● Heart is the size of a fist.
● Blood flow will take you to the 4 chambers in the heart: Right atrium, Left atrium, Right ventricle, Pulmonary valve.
● Arteries carry blood away from the heart.
● Veins carry blood into the heart.
Functions of the different parts of hearts:
● Superior vena cava - carries blood from the upper body TO the heart
● Inferior vena cava - carries blood from lower body TO the heart
● Pulmonary Veins - transfer oxygenated blood from the lungs to the left side of heart
● Pulmonary artery - carries deoxygenated blood to your lungs
● Valves - prevent the backward flow of blood
● Aorta - carries oxygen-rich blood away from the heart to the rest of the body.
● Atrium - It helps blood flow smoothly back to the heart while the heart is pumping
● Ventricles - The ventricles pump blood out of the heart: the right ventricle sends blood to the lungs, and the left ventricle sends blood to the rest of the body.
● Capillaries - tiny blood vessels have thin walls. Oxygen and nutrients from the blood can move through the walls and get into organs and tissues. Capillaries are where oxygen and nutrients are exchanged for carbon dioxide and waste.
● Arteries - carry oxygen rich blood to the rest of your body
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Importance of different parts of hearts:
● Superior Vena Cava - without this, there would be no circulation of blood, causing organ failure
● Inferior Vena Cava - Without the inferior vena cava, the body would struggle to return deoxygenated blood from the lower half, leading to blood accumulation, swelling, reduced oxygen supply, and potentially life-threatening organ dysfunction.
● Pulmonary Veins - oxygenated blood from the lungs wouldn't return to the heart, leading to severe oxygen deprivation in the body, respiratory failure, and ultimately life-threatening
● Pulmovary Artery - Without the pulmonary artery, deoxygenated blood would be unable to flow from the heart to the lungs for oxygenation, resulting in a buildup of carbon dioxide and severe oxygen deprivation in the body.
● Valves - Without valves, blood would flow backward and fail to circulate efficiently, leading to reduced blood pressure, inadequate organ perfusion, and potentially life-threatening circulatory issues.
● Aorta - Without the aorta, oxygenated blood would be unable to exit the heart to supply the body, leading to rapid organ failure and death due to lack of essential nutrients and oxygen.
● Atrium - Without atria, the heart would struggle to collect and efficiently pump blood into the ventricles, leading to impaired circulation and inadequate blood flow to the body and lungs.
● Ventricles - Without ventricles, the heart would be unable to pump blood effectively to the lungs and the rest of the body, resulting in immediate circulatory failure and death.
● Capillaries - Without capillaries, the exchange of oxygen, nutrients, and waste products between blood and tissues would be impossible, leading to severe tissue damage and organ failure.
● Arteries - Without arteries, oxygenated blood could not be transported from the heart to the body's tissues, resulting in immediate and life-threatening oxygen deprivation.