Cellular Respiration (2.8)IB Diploma Biology

Essential Idea: Respiration allows organisms to control the release of chemical energy

from organic molecules in their food

BELL RINGER

• Why do humans need to breathe oxygen?

• Is breathing oxygen a characteristics of ALL living things?

Cellular Respiration (2.8)IB Diploma Biology

Essential Idea: Respiration allows organisms to control the release of chemical energy

from organic molecules in their food

2.8.1 Cell respiration is the controlled release of energy from organic compounds to produce ATP.

2.8.1 Cell respiration is the controlled release of energy from organic compounds to produce ATP.

Chemical energy stored in bonds

2.8.1 Cell respiration is the controlled release of energy from organic compounds to produce ATP.

FLASHBACK: 2.3.7 Lipids are more suitable for long-term energy storage in humans than carbohydrates.

2.8.1 Cell respiration is the controlled release of energy from organic compounds to produce ATP.

2.8.1 Cell respiration is the controlled release of energy from organic compounds to produce ATP.

2.8.1 Cell respiration is the controlled release of energy from organic compounds to produce ATP.

2.8.2 ATP from cell respiration is immediately available as a source of energy in the cell.

2.8.2 ATP from cell respiration is immediately available as a source of energy in the cell.

http://www.biologyinmotion.com/atp/index.html

2.8.2 ATP from cell respiration is immediately available as a source of energy in the cell.

Hydrolysis of ATP to ADP is an exothermic process (energy is released for cellular use and is ultimately converted to heat)

2.8.2 ATP from cell respiration is immediately available as a source of energy in the cell.

2.8.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

2.8.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

GLYCOLYSIS (Glucose – Splitting!)

2.8.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

2.8.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

2.8.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

2.8.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

2.8.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

• Anaerobic Respiration Summary:– Yields 2 ATP per glucose (from Glycolysis)– No oxygen needed– IN ANIMALS:• Glucose Lactate + 2 ATP

– IN YEAST & PLANTS:• Glucose Ethanol + Carbon Dioxide + 2 ATP

– Happens in Cytoplasm– Useful for…• Short, rapid bursts of ATP production• When oxygen supplies are low (i.e. intense exercise)• In low-oxygen environments (i.e. waterlogged soil)

2.8.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

Yeast is a unicellular fungus that can respire aerobically or anaerobically

Anaerobic respiration in yeast (aka Alcohol Fermentation) is used to produce ethanol which is the basis of most alcoholic beverages as well as bioethanol fuels (from sugar cane and corn)

2.8.5 Use of anaerobic cell respiration in yeasts to produce ethanol and carbon dioxide in baking.

2.8.5 Use of anaerobic cell respiration in yeasts to produce ethanol and carbon dioxide in baking.

Anaerobic respiration in yeast also makes it a useful leavening agent in baking. Carbon dioxide released from respiration creates air bubbles in dough, causing it to rise. The ethanol by-product evaporates during baking.

2.8.6 Lactate production in humans when anaerobic respiration is used to maximize the power of muscle contractions.

An adaptation that allowed early humans to escape predators

Anaerobic respiration in humans (aka Lactic Acid fermentation) can supply additional ATP, quickly, for a short period when oxygen is low

Lactate (lactic acid) builds up in muscle tissue until max limit. Oxygen must be absorbed to break it down (oxygen debt)

2.8.4 Aerobic cell respiration requires oxygen and gives a large yield of ATP from glucose.

2.8.4 Aerobic cell respiration requires oxygen and gives a large yield of ATP from glucose.

2.8.4 Aerobic cell respiration requires oxygen and gives a large yield of ATP from glucose.

2.8.4 Aerobic cell respiration requires oxygen and gives a large yield of ATP from glucose.

2.8.4 Aerobic cell respiration requires oxygen and gives a large yield of ATP from glucose.

• Aerobic Respiration Summary:– Yields 36 ATP per glucose (from Glycolysis as well as

following chemical reactions)– Oxygen needed– Glucose + Oxygen Water + Carbon Dioxide + 36 ATP– Happens in Mitochondria

• Respirometer: A device used to measure respiration rate. Most involve:– A sealed container to contain living tissue– An alkali (i.e. KOH) to absorb carbon dioxide– A capillary tube or pipette connected to the container• As oxygen is used up, the fluid moves toward the container

2.8.7 Analysis of results from experiments involving measurement of respiration rates in germinating seeds or invertebrates using a respirometer.

• A Respirometer could be used to measure…– Respiration rates of different organisms– Effect of temperature on respiration– Comparing respiration in active v. inactive organisms

2.8.7 Analysis of results from experiments involving measurement of respiration rates in germinating seeds or invertebrates using a respirometer.