Aerobic and Anaerobic Respiration

• There are two types of respiration - aerobic and anaerobic.

Aerobic Respiration

• Requires Glucose + Oxygen to produce Carbon Dioxide + Water + ATP (Energy).
• Glucose breaks down completely in mitochondria for a larger ATP yield than anaerobic respiration.
• Lactic acid is created.
• Cell respiration is the controlled release of energy from organic compounds to release ATP.
• Considered a form of aerobic respiration.

Anaerobic Respiration

• Does not use oxygen.
• Breaks down glucose using glycolysis to create pyruvate, lactic acid, and ATP.
• Plants produce alcohol, CO2, and ATP.
• Occurs in the cytoplasm and mitochondrion of the cell.

ATP

• Adenosine triphosphate is a high energy molecule.
• One molecule of ATP has three phosphate groups.
• ATP breaks down into ADP + Pi, releasing energy used by cells.
• Cell respiration uses stored energy to regenerate ATP from ADP + Pi.

Respiratory System

• Air enters via the nose or mouth, travels through the pharynx to the trachea.
• Air continues down the trachea, dividing into two bronchi connecting to the lungs.
• Inside the lungs, the bronchi divide into smaller airways called bronchioles.
• Bronchioles increase surface area and end in air sacs called alveoli.
• Gas exchange occurs in alveoli with the bloodstream.

Alveoli

• Composed of two cell types - Pneumocytes 1 and 2 - and only one cell thick.
• High surface area to volume ratio for efficiency and are covered in mucus.

Alveolar Tissue Cells

• Type I Pneumocyte cells are squamous, extremely thin, and cover approximately 95% of alveolar surface. They're involved in gas exchange.
• Type II Pneumocyte cells are granular, roughly cuboidal, covering about 5% of alveolar surface, and secrete pulmonary surfactant.

Mechanisms of Breathing

• Inhalation involves the contraction of external intercostals which expand the thorax, and the diaphragm, which contracts and lowers.
• Thorax volume increases while pressure decreases, causing air to flow in.
• Exhalation involves the relaxation of external intercostals and the diaphragm moving up.
• Elastic recoil of the lungs lowers thorax volume and increases pressure, causing air to flow out.

Lung Disorders

• Lung cancer involves uncontrolled lung cell production, leading to abnormal tissue growth that can impact normal lung function.
• Symptoms include coughing up blood, wheezing, respiratory distress, and weight loss.
• Emphysema is a condition where alveoli walls lose elasticity, leading to abnormal enlargement and decreased efficiency.
• Phagocytes produce elastase to help, but elastase breaks down lung fibers.
• Symptoms of emphysema include shortness of breath, phlegm, expansion of the ribcage, cyanosis, and increased chest infections.
• Asthma involves chronic inflammation of airways, specifically the bronchi and bronchioles.
• Symptoms include shortness of breath, chest tightness, wheezing, and coughing.

Histology

• The digestive system consists of two major groups of organs.
• One major group consists of the alimentary canal, where food travels through.
• Canal components include the mouth, esophagus, stomach, small intestine, large intestine, and rectum.
• The Oesophagus is a hollow tube connecting the oral cavity to the stomach.
• The Stomach is a temporary storage tank that mixes food, where protein digestion then begins.
• Lined with gastric pits that release digestive juices.
• The Small Intestine is a long, highly folded tube that absorbs usable food substances.
• The Large Intestine is the final section of the alimentary canal, where water and minerals are absorbed.
• The Rectum is the final section of the alimentary canal.
• Accessory organs aid digestion without transferring food.
• These organs include salivary glands that release saliva and the pancreas that produces a broad spectrum of enzymes released into the small intestine.
• The Liver takes raw materials absorbed by the small intestine and uses them to make key chemicals.
• The Gall Bladder stores bile produced by the liver.

Enzymes

• Amylase breaks down carbohydrates.

Small Intestine

• The tissue is composed of four main layers: serosa, muscle, submucosa, and mucosa.
• The serosa is a protective outer covering composed of a layer of cells.
• The muscle layer allows peristalsis through uncontrolled muscle reflex.
• The submucosa is a tissue layer separating the muscle layer from the innermost mucosa.
• The mucosa is a folded inner layer that absorbs nutrients.

Villi

• Villi form the lining of the intestine.
• They have a rich blood supply and increase surface area to maximize nutrient absorption.

Digestion

• Food is digested through chemical and mechanical digestion.
• Mechanical digestion is done by peristalsis.
• Chemical digestion occurs in many sections, including ingestion in the mouth, chemical digestion in the mouth, stomach, and duodenum, absorption in the ileum, assimilation in the liver, and egestion in the rectum.

Locations of Enzymatic Digestion

• The Esophagus uses salivary amylase to break down starch into maltose.
• The Stomach uses proteases to break down protein into polypeptides and stomach acids for chemical digestion.
• The Liver / Gall Bladder uses bile salts for emulsification of lipids.
• The Pancreas uses amylase to break down starch into maltose, lipase to break down triglycerides into fatty acids, endopeptidase to break down peptides into amino acids, nuclease to break down DNA/RNA into nucleosides, and bicarbonate ions to neutralize stomach acid.

Blood Glucose Concentration

• Refers to the amount of sugar in the bloodstream.
• Insulin converts glucose into glycogen to lower it
• Beta cells in the pancreas release insulin when blood glucose levels are high and Alpha cells in the pancreas release glucagon when blood glucose levels are low.
• Blood glucose is controlled via a negative feedback loop.
• When there is low blood sugar Alpha cells release glucagon that stimulates glycogen, which turns into glucose and is released into the bloodstream, optimizing blood sugar level.
• When there is high blood sugar beta cells release insulin, glucose is taken into cells and stored as glycogen, optimizing blood sugar level.
• Diabetes can be diagnosed with a glucose test.
• There are two types of diabetes.
• Type 1 diabetes, or juvenile diabetes, is when a person is born and relies on insulin.
• Type 2 diabetes, or adult-onset diabetes, is when a person does not rely on insulin, depending on severity. It can be controlled through exercise and eating well.

Circulatory System

• Blood consists of 55% plasma and 45% blood cells (erythrocytes), with only 1% being white blood cells and platelets.
• Delivers oxygen and nutrients to cells.

Erythrocytes

• Contain haemoglobin, a special pigment that combines with oxygen.
• No nucleus, allowing for more space for haemoglobin and oxygen.

Blood Vessels

• There are three main types: arteries, veins, and capillaries.
• Arteries move blood away from the heart.
• Arteries are usually high in oxygen, high pressure, and high thickness.
• Veins move blood to the heart.
• Veins are generally low in oxygen and have valves.
• Capillaries link arteries and veins together where exchange of nutrients and materials occurs.
• Capillaries are only one cell thick, allowing for gas exchange.

Oxygen Transport

• Oxygen is transported throughout the body by a protein called haemoglobin.
• Haemoglobin is a four-polypeptide chain that can carry four oxygen atoms at a time following the formula Hb + 4O2 = HbO8.

Oxygen Dissociation Curves

• Show the relationship between oxygen levels and haemoglobin saturation.
• The oxygen dissociation curve for adult haemoglobin is sigmoidal due to cooperative binding.

Myoglobin

• Oxygen-binding molecule found in skeletal muscle.
• It has a single polypeptide with one heme group and becomes fully saturated quicker than haemoglobin. Myoglobin has no cooperative binding.

Heart Muscles

• They're composed of cardiac muscle, which is striated, meaning it has stripes that appear throughout the muscle tissue.
• It is branches allowing heart muscles to contract and relax synchronously.

Nuclei

• Cardiac muscles have central nuclei.
• Intercalated disks are junctions between muscle cells enabling impulses to spread rapidly between cells.
• Cardiac muscles are spontaneous and involuntary.

Heart Structure

• There are 4 chambers – 2 upper atria and 2 lower ventricles.
• Valves ensure proper blood flow.
• The coronary artery is a vessel on the surface of the heart that supplies it with nutrients.
• Both sides of the heart pump at the same time.

Blood Circulation

• Blood travels from the superior and inferior vena cava to the right atrium.
• From the right atrium to the right ventricle, pulmonary artery, the lungs, the left atrium, and then the left ventricle, aorta, and the rest of the body.

Heartbeat

• The heart is spontaneous and initiates an impulse from special fibres in the right atrial wall.
• The Sino-atrial node (SAN) or pacemaker controls heart beat
• Different factors affect heart rate, including epinephrine (adrenaline) and parasympathetic influence (vagus).
• When the ventricles contract, it is Systole, and when the ventricles relax, it is Diastole.

ECG / Electrocardiography

• This has several sections.
• The P-Wave represents depolarization of the atria in response to SA node triggering.
• The PR Interval represents a delay of the AV node to allow filling of ventricles.
• The QRS Complex represents depolarization of ventricles that triggers main pumping contractions.
• The ST Segment begins ventricle repolarization and should be flat.
• The T-Wave represents Ventricular repolarization.
• Depolarization means to contract and Repolarization means to relax.

SI Units, Metric Prefixes, and Scientific Notation

• Physical Quantity: Length, Mass, Time
• Symbol of Quantity: l, m, t
• Name of Unit: Metre, Kilogram, Second
• Symbol for Unit: m, kg, s
• Scientific notation is a shorthand way of expressing very large or very small numbers in terms of a decimal number between 1 and 10, multiplied by the power of 10. Numbers written in exponential notation have just one numeral before the decimal point. For example, the diameter of a red blood cell is 0.000002 metres = 2.0 x 10^-6 in.

Accuracy and Precision

• Accuracy is the closeness with the true value of the quantity being measured.
• Precision is the measure of the reproducibility of the measurement.
• Accuracy can be determined with one measurement.
• Precision must be determined with several measurements.

Reporting Measurements and Data

• When reporting the measurements three things need to be stated; the best estimate from the set of measurements, absolute uncertainty and units.
• The best estimate is usually the average (mean).
• Absolute uncertainty is reported by half the range of measurements, thought of as the deviation of values around the mean.
• Units also need to be stated.

Absolute and Percentage Uncertainties

• Absolute error is the range within which the true value is expected to lie
• Absolute error is the difference between the measured value and the true value

Determining outliers and anomalies

• An outlier is a value that is much smaller or larger than most of the other values in a set of data.
• An anomaly is a false data point, often the result of a faulty observation or wrong equipment.

Newton's Laws of Motion

• 1st law (Inertia): An object will maintain its state of motion unless it is acted on by an unbalanced force.
• There are two components, an object at rest will stay at rest, and an object in motion will continue at its velocity. An example would be a car travelling at speed limit, or sitting on a chair.
• 2nd Law: The acceleration of an object is directly proportional to the objects net force.
• 3rd Law: For every action there is an equal and opposite reaction.

Forces

• A force is an interaction that causes a change in the motion or shape of an object.
• Can have one or more effects on an object, including change in speed, change in direction, and a change in shape.
• Forces can either push, pull, or twist.
• Forces are measured in Newtons (N).
• The sum of all forces acting on an object is called the net force.
• Balanced forces are forces that cancel each other out
• The resulting net force is zero in a balanced fore

Unbalanced forces

• Two or more forces that do not cancel each other out
• The net force does not equal zero
• With an unbalanced force there will be a change in motion, the action of thrust enables the propulsion of rockets.
• Thrust is generated when a mass is accelerated in one direction creating a reaction force in the opposite direction.

Describing Motion

• Scalar is a quantity that has a magnitude but no direction
• Vector is a quantity that has both magnitude and direction.

Distance and Displacement

• A distance is the measurement of the actual path travelled by an object.
• Displacement is how far away an object is from its original position.

Speed

• Speed is a measure of how fast something moves; it is a scalar measurement
• Average speed is an overall measurement of speed between two points in time.
• Instantaneous speed is a measure of speed at a particular point in time.
• Speed can be converted to m/s to Km/h by multiplying or dividing by 3.6.

Velocity

• Velocity is the measure of the rate at which displacement changes and is a vector measurement.
• Using the formula for acceleration, final velocity can be found.

Acceleration

• Acceleration is a measure of the rate of change of velocity and measures how quickly velocity increases or decreases, describing a vector quantity.

Positive and Negative Acceleration

• When an object experiences an increase of speed, it will have a positive value for acceleration.
• When an object experiences a decrease of speed, it will have a negative value for acceleration.
• Acceleration due to gravity means all objects are attracted to earth and move toward earth at a constant velocity instead they accelerate towards earth at 9.8m/s^2.

Free-Fall Motion

• Any motion on a body, where gravity is the only force acting on it.

Vertical free fall motion

• Object is dropped or thrown down
• Object is thrown up

Time and Displacement Graphs

• Illustrate how the position of an object changes over time.
• Time always runs horizontally on the x axis and Distance runs vertically on the y axis
• The gradient of a displacement / distance time graph is the velocity
• A horizontal line means the object is stationery, and a downwards slope means the object is slowing down.
• The gradient of the line on a distance time graph represents speed, where the steeper the slope the greater the speed and the slope can be used to compare the speed of objects.

Velocity / Speed Time Graphs

• Velocity time graph shows how an object's speed changes over time, plotting the velocity on the y-axis and time on the x-axis.