Respiration RESPIRATION Involves the release of energy and

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 “re-stored” 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)

Anaerobic Respiration (aka fermentation) Step 1: 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 CO 2) 2 ethyl alcohol + 2 CO 2 - In bacteria, used to make -in yeast, bacteria: - cheese, yogurt used to make beer, - In humans leads to muscle wine and bread fatigue when O 2 is low TOTAL ATP= 2 Glycolysis clip

Glucose (6 - carbon +2 ATP 4 ATP ( net gain 2 ATP, the only ATP release 2 Pyruvic acid (3 - carbon) 2 Lactic Acid (no CO 2) - In bacteria, used to make - cheese, yogurt - In humans leads to muscle fatigue when O 2 is low 2 ethyl alcohol + 2 CO 2 -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 CO 2 + 6 H 2 O + 36 ATP Looks like this:

Glucose + 2 ATP (6 Carbon) 4 ATP (net 2 ATP) 2 Pyruvic Acid (3 carbon) * O 2* 2 acetyl Co. A (a 2 carbon compound combined w a co-enzyme) + 2 CO 2 (exhaled) Krebs cycle H High energy Oxidation/ Reduction 4 CO 2 + 2 ATP (net 2 ATP) Electron Transport Chain low energy 32 ATP (net of 32 ATP) [ e- gives up energy] H O 2 final H acceptor 6 H 2 O (vapor)

end products: 6 CO 2 + 6 H 2 O + 36 ATP

Krebs Cycle Each turn of the Krebs cycle produces: 1. CO 2 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 H 2 O (vapor)

Summary of Reactions C 6 H 12 O 6 (aerobic) pyruvic acid + O 2 CO 2+H 2 O + 36 ATP C 6 H 12 O 6 pyruvic acid lactic acid + 2 ATP (anaerobic } humans and bacteria) C 6 H 12 O 6 pyruvic acid ethyl alcohol + CO 2 + 2 ATP (anaerobic } bacteria and yeast) like our balloon demo

Gas Exchange The exchange of O 2 and CO 2 between an organism and the environment the gas exchange surface must be: › › Thin Moist In contact with O 2 Near a transport system Adaptations for Gas Exchange 1. Monera, Protist, and Fungi- diffusion occurs across thin, moist 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)

“Cowboy respiration’ clip

Respiration in Humans a)Cellular Aerobic: C 6 H 12 O 6 cellular gas exchange CO 2 H 2 O + 36 ATP Anaerobic: (when O 2 is not in high supply) C 6 H 12 O 6 lactic acid + 2 ATP b) Gas exchange: occurs between the external environment through out 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 ling 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 a an alveolus(plural- alveoli) 8. Alveoli- “air sacs” Microscopic, 1 cell thick Functional unit of resp. system where gas exchange occurs ( O 2 CO 2) surrounded by capillaries

9. Lung- each bronchi 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 CO 2 concentration in blood - Chemo receptors in vessels send message to medulla in brain - - High [CO 2]-faster rate of breathing - Low [CO 2]- slower - Medulla affects rate of diaphragm

Gas Exchange Capillaries surround alveoli O 2 goes into the blood Carried as oxyhemoglobin (Hb. O 2) O 2 diffuses into cells Used for aerobic respiration Products of cellular respiration (CO 2 + H 2 O) diffuse into blood * CO 2 carried in plasma once in lungs, CO 2 + H 2 O are released during exhalation

3 ways CO 2 is carried in your blood v 70% as a bicarbonate ion in your plasma carbonic CO 2 + H 2 O anhydrase carbonic acid (H 2 CO 3) bicarbonate H ion (HCO 3) The bicarbonate ions reduce the p. H in your blood and this is detected by the medulla. v 20 % as carboxyhemoglobin (Hb. CO 2) on RBCs v 10 % floats in your plasma as CO 2

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 Ø 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 O 2 - Be experienced (10 -15 years)