Respiration

**__Topical Essential Questions__**
Matter is broken down to release energy. Matter needs energy to perform different processes. Energy is used to transform matter. Matter can also store energy.
 * 1. What is the relationship between energy and matter?**

Energy is needed to fuel metabolism processes within the body. (e.g. moving, eating, respiration, digestion) Large organisms need energy to generate heat that will regulate their body temperature. This allows them to adapt to large variations of temperature due to their large surface to volume ratio.
 * 2. How is energy significant to biological system?**

No. This is because an organism need to constantly maintain a suitable internal environment to allow the body to survive and therefore, exchange of matter with its environment is needed to maintain this equilibrium. (e.g. photosynthesis, respiration and all living systems!)
 * 3. Can an organism survive without the exchange of matter with its environment?**

Matters are things that take up space and have mass. Not all matters are living as non-living things are made up of matters too. Living organisms are made of matter, which consists of millions of atoms and molecules to make up our various body cells, tissues, organs and systems.
 * 4. Are all matters living and all living organisms made of matter?**

No, energy cannot not be created and destroyed. Rather, living organisms transfer one form of energy to another in order to produce energy that is needed to fuel the various processes in their bodies. Similarly, energy is not destroyed but rather used up or wasted by being transferred to other forms of energy such as heat.
 * 5. Can living organisms create and destroy energy?**

No, living organisms break down matter or join matter to form the different type of things needed for their own survival.
 * 6. Can living organisms create and destroy matter?**

molecules are build up (from simple to complex)- anabolism molecules broken down (from complex to simple)- catabolism

__**Unit essential Questions**__
- Why do we need to respire? - Do the structure and organisation of the living system change when energy is released from them? - How are respiratory systems of animals organised efficiently to carry out its functions? - Can there be any metabolism without enzymes? Enzymes increase rate of chemical reactions, lower activation energy thus increasing rate of processes.

Glycolysis- break down glucose in cytoplasm from 6C to 3C molecule - can happen without oxygen

Krebs Cycle- further broken down into carbon dioxide

Electron Transpore and oxidative phosphorylation- in inner membrane of mitochondria

inner sac of mitochondria is folded to increase surface area for synthesising ATP

Respiratory substrate: Glucose

Glycolysis (oxygen independent, 1 molecule of glucose (6C) broken down to 2 molecules of pyruvate (3C) -> Krebs Cycle (oxgen dependent- drives reaction at stage 3) occurs in the matrix of mitochondria -> Electron Transport Chain (oxygen dependent, accounts for 90% of ATP generated by oxygen) Oxidative phospholyration (aerobic respiration) 6 NADH2 -> 6 X 2 ATP 2 FADH2 -> 2 X 2 ATP

lactic acid -> convert pyvorate to lactic acid as there is no oxygen to drive the krebs cycle and ETC (cause cramps and muscle aches-> massage area to disperse the lactic acid into other parts with oxygen)

Meat-> Muscles Fatty meats are just fatty muscles face have chambers -> allow sound to resonate and causes mucus to accumulate volume in this area increase, pressure will drop bell jar experiment: pull down rubber sheet (diaphragm) -> increase volume of thoracic cavity -> pressure decreases -> pressure of surrounding increases -> air will enter decreasing volume leads to increase in pressure -> air leaves

dissolved carbon dioxide forms carbonic acid, therefore our blood is slightly acidic. reversed when it returns to the lungs mechanism of controlling breathing is determined by the presence of carbon dioxide (not the lack of oxygen) -> by monitoring pH of blood, presence of carbonic acid

What about other factors that lower pH of blood? Stimulate body to increase the rate of breathing and hyperventilate.

Carbon monoxide is like oxygen and binds to hemoglobin. However, it does not dissociate from hemoglobin as easily as oxygen (more permanent). Since most of the hemoglobins will be occupied, this will decrease the rate of transport of oxygen -> person exposed to carbon monoxide will gradually fall alseep (due to lack of oxygen) and pass away