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Respiration RESPIRATION • Involves the release of energy and gas exchange • Occurs in all cells of all organisms • It is the release of energy from food (glucose) – “life runs on sugar” • Energy is stored as ATP (a high energy compound) and is released and “restored” in a cycle ATP Energy in Energy out ADP + P Cells use a few billion ATP molecules per minute for cell activities ATP cycle clip Two types of respiration Anaerobic Absence of O 2 Used by some simple organisms (yeast and bacteria) Occurs in the cytoplasm Partial breakdown of glucose Less efficient (less ATP) Aerobic uses O 2 Used by most organisms Occurs in the mitochondria Complete breakdown of glucose More efficient (more ATP per glucose) Step 1: Anaerobic Respiration (aka fermentation) Glycolysis: breakdown Of glucose into pyruvic acid Glucose +2 ATP (6- carbon) 4 ATP ( net gain 2 ATP, the only ATP released) 2 Pyruvic acid (3- carbon) Pyruvic acid (from previous slide) (3- carbon) Step 2: Fermentationpyruvic acid converted to another end product. No more ATP released. 2 Lactic Acid (no CO2) - In bacteria, used to make - cheese, yogurt - In humans leads to muscle fatigue when O2 is low 2 ethyl alcohol + 2CO2 -in yeast, bacteria: used to make beer, wine and bread TOTAL ATP= 2 Glycolysis clip Glucose (6- carbon +2 ATP 4 ATP ( net gain 2 ATP, the only ATP released 2 Pyruvic acid (3- carbon) 2 Lactic Acid (no CO2) - In bacteria, used to make - cheese, yogurt - In humans leads to muscle fatigue when O2 is low 2 ethyl alcohol + 2CO2 -in yeast, bacteria and used to make beer, wine and bread TOTAL ATP= 2 Glycolysis song click glucose, glucose Aerobic Respiration • Cristae in mitochondria provide a large surface area for the series of reactions that occur during aerobic respiration • Step 1: “Anaerobic Phase”- glycolysis occurs in the cytoplasm • Step 2: “Aerobic Phase”- occurs in the mitochondria • End Products: 6 CO2 + 6 H2O + 36 ATP Looks like this: Glucose + 2ATP (6 Carbon) 4 ATP (net 2 ATP) 2 Pyruvic Acid (3 carbon) * O2 * 2 acetyl CoA (a 2 carbon compound combined w a co-enzyme) + 2CO2 (exhaled) Krebs cycle High energy Oxidation/ Reduction 4 CO2 + 2ATP H Electron Transport Chain low energy 32 ATP [ e- gives up energy] H O2 final H acceptor 6 H 2O (vapor) end products: 6 CO2 + 6 H2O + 36 ATP Krebs Cycle Each turn of the Krebs cycle produces: 1. CO2 2. ATP 3. Hydrogen- high energy hydrogen atoms are picked up by coenzymes NAD + FAD and carried to the electron transport chain During the e- transport chain (ETC) • Oxidation occurs when some atoms lose e- (via a gain of H) • Reduction occurs when some atoms gain e- (via a loss of H) • Collectively this is called oxidation- reduction • Low energy H’s combine with free oxygen (the final H acceptor) to form H2O (vapor) Summary of Reactions C6H12O6 (aerobic) pyruvic acid + O2 CO2+H2O + 36 ATP C6H12O6 pyruvic acid lactic acid + 2ATP (anaerobic } humans and bacteria) C6H12O6 pyruvic acid ethyl alcohol + CO2 + 2 ATP (anaerobic } bacteria and yeast) “Cowboy respiration’ clip like our balloon demo Gas Exchange • The exchange of O2 and CO2 between an organism and the environment • the gas exchange surface must be: – Thin – Moist – In contact with O2 – Near a transport system Adaptations for Gas Exchange diffusion occurs across thin, 1.Monera, Protist, and Fungimoist cell membrane 2. Plants- respire 24 hours a day • gas exchange occurs in: leaves(stomates and the spongy layer) • Stems (lenticles) • roots (root hairs) 3. Land Animals- the trick is to keep the respiratory surfaces moist! (see awesome adaptation sheet) Respiration in Humans a)Cellular Aerobic: O2+C6H12 O6 cellular gas exchange CO2 +H2O + 36 ATP Anaerobic: (when O2 is not in high supply) C6H12 O6 lactic acid + 2ATP b) Gas exchange: occurs between the external environment through our respiratory system. Functional organization of the respiratory system 1. Nasal cavity • warms • filters (ciliated mucous membranes) • moistens air 2. Pharynx- “throat” • area where oral and nasal cavities meet 3. Larynx- “voice box” • beginning of the trachea, • mostly cartilage, • has two pairs of membranes vocal cords 4. Epiglottis • flap of cartilage that covers the larynx when you swallow • prevents choking 5. Trachea- “windpipe” • lined with ciliated mucous membranes • has cartilage rings to prevent collapse 6. Bronchi- 2 branches of the trachea • Each branch leads to a lung • Contain cartilage and ciliated mucous membranes 7. Bronchioles- smaller branches of bronchi in each lung (AKA bronchial tubes) • no cartilage • contains mucous membranes • each ends in an alveolus(plural- alveoli) 8. Alveoli- “air sacs” • Microscopic, 1 cell thick • Functional unit of resp. system where gas exchange occurs ( O2 CO2) • surrounded by capillaries 9. Lung- each bronchus with bronchioles and alveoli is a lung »elastic 10. Pleura- membrane surrounding the lung 11. Diaphragm- muscle under the lungs • Helps to control breathing Mechanisms for Gas Exchange Breathing- the movement of air in and out of the body a) inhalation- the diaphragm contracts and moves down Chest cavity expands Pressure in the cavity decreases Air rushes into the lungs b) exhalation- diaphragm relaxes and moves up (exhalation cont. ) • Chest cavity gets smaller • Pressure in cavity increases • Air is pushed out of lungs The rate at which you breathe: - Mostly involuntary At 12-25 breaths per minute Regulated by CO2 concentration in blood Chemo receptors in vessels send message to medulla in brain - High [CO2]-faster rate of breathing - Low [CO2]- slower - Medulla affects rate of diaphragm Gas Exchange Capillaries surround alveoli O2 goes into the blood Carried as oxyhemoglobin (HbO2) O2 diffuses into cells Used for aerobic respiration Products of cellular respiration (CO2 + H2O) diffuse into blood * CO2 carried in plasma once in lungs, CO2 + H2O are released during exhalation Inside an Alveolus OO O222 Inhalation/Exhalation: Alveolus is 1 cell thick O2 CO2 O2 CO2 O2 CO2 O2 O2 CO2 O2 CO2 O2 O2 CO2 Capillary blood vessel is 1 cell thick – What is the purpose of that? 3 ways CO2 is carried in your blood 70% as a bicarbonate ion in your plasma carbonic CO2 + H2O anhydrase carbonic acid bicarbonate ion (H2CO3) (HCO3) The bicarbonate ions reduce the pH in your blood and this is detected by the medulla. 20 % as carboxyhemoglobin (HbCO2) on RBCs 10 % floats in your plasma as CO2 High Altitudes Hypoxia Initially to compensate- hyperventilate and an increase in RBC (blood like motor oil) 25% of climbers experience: AMS- Acute Mountain Sickness brain swelling, headaches, nausea, weakness and shortness of breath 3660 meters: Some people experience HACE- High Altitude Cerebral Edema - brain swells severely - trouble walking; using hands - may hallucinate HAPE- High Altitude Pulmonary Edema - lungs fill with fluid Mt. Everest Climbers (Summit 8848 m) - climb slowly - Use bottled O2 - Be experienced (10-15 years)