6B_Matters,+System+&+Organisation

Matters, System & Organisation__**
 * __29 June 2010

Macromolecules Photosynthesis - anabolism - Energy is needed - SUNLIGHT Respirations - catabolism

Unit Essential Questions 1. Why do we need to respire? 2. Do the structures and organisation of the living system change when energy is released from them? - Yes. - Mitochondria 3. How are the respiratory systems of animals organised efficiently to carry out its functions? 4. Can there be any metabolism without enzymes? - Enzymes speed up reaction

Unit Enduring Understanding 1. living organisms release energy within the biological molecule into forms they can use to carry out life processes 2. Process of the release of energy is affected by external environment 3. The structure and organisation of the respiratory system is dictated by the function that it serves 4. Metabolic pathway is a sequence of enzyme-controlled reations

Respiration - Its an energy-making process - Like fire, the body needs oxygen and a fuel - Oxygen and digested food travel through the human body - End up in the same place - Blood needs to carry oxygen and food for energy to be produced/released - Also produces waste products - Carbon Dioxide - Needs to be removed - CELLULAR REPIRATION - Aerobic respiration of glucose: - C6H12O6 + 6O2 --> 6CO2 + 6H20 + Energy (ATP) - The energy is released in the form of ATP

Uses of Energy - Muscle contraction - Protein synthesis - Cell division - Active transport - Building up of protoplasm for growth - Transmission of nerve impulsion

Drowning - Humans can die from drowning - What is the cause of death? - DISCUSS - We need oxygen to do work, when we stop breathing, turn pale or spasms - When you dont run for a year, your legs will become red and itchy - When you pant, you are returning the oxygen debt - Why cant cockroaches drown? - Oxygen has to enter our bloodstream - We breathe in air, not oxygen - Oxygen enters the bloodstream due to diffusion - Same as for nitrogen, but our bloodstream does not need it

Properties of gas exchange surfaces - Large surface area to volume ration - Thin membrane - Moisture - Efficient transport system

The human respiratory system - Intercostal muscle - RIBS - Ribs are attached to the cartilage - The sternum is at the bottom of the cartilage, which is where we push when we give CPR - Alveoli: very thin, gaseous exchange in here - Breathing: The lungs canot inhale and exhale on their own - they dont have muscles for this
 * They rely on the contraction and the relaxation of the intercostal muscles and the diaphragm

- Red blood cells have haemoglobin that carry the oxygen - There is always dissolved carbon dioxide in the blood, which causes the blood to be slightly acidic - When the pH in your body is lowered, you body will make you breath harder to take in more oxygen -