Lecture 8 Fermentation and Cellular Rspiration

Lecture 8 Fermentation and Cellular Rspiration - Cellular...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon
Cellular Respiration: Harvesting Chemical Energy
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Thermodynamics in the Real World Energy flows into an ecosystem as sunlight and leaves as heat Light energy ECOSYSTEM CO 2 + H 2 O Photosynthesis in chloroplasts Cellular respiration in mitochondria Organic molecules + O 2 ATP powers most cellular work Heat energy Figure 9.2
Background image of page 2
ATP synthesis from ADP + P i requires energy ATP ADP + P i Energy for cellular work (endergonic, energy- consuming processes) Energy from catabolism (exergonic, energy yielding processes) ATP hydrolysis to ADP + P i yields energy Figure 8.12 Catabolic Pathways Anabolic Pathways To keep working Cells must regenerate ATP
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Catabolic Pathways Produce ATP The breakdown of organic molecules is exergonic
Background image of page 4
Cellular Respiration Is a catabolic pathway that yields energy by oxidizing organic fuel to produce energy in the form of ATP Organic Fuel + O 2 CO 2 + H 2 O + Energy Fats, Carbohydrates, Protein
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Cellular respiration -Is the most prevalent and efficient catabolic pathway -Consumes oxygen and organic molecules such as glucose -Yields ATP Example--glucose C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy (Fuel) (Stored as ATP)
Background image of page 6
Redox Reactions: Oxidation and Reduction Catabolic pathways yield energy Due to the transfer of electrons Redox reactions Transfer electrons from one reactant to another by oxidation and reduction XH + Y X + YH
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
In oxidation A substance loses electrons, or is oxidized In reduction A substance gains electrons, or is reduced XH + Y X + YH becomes oxidized (loses electron) becomes reduced (gains electron)
Background image of page 8
Examples of redox reactions Na + Cl Na + + Cl becomes oxidized (loses electron) becomes reduced (gains electron)
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Some redox reactions Do not completely exchange electrons Change the degree of electron sharing in covalent bonds CH 4 H C O O O O O C Methane (reducing agent) Oxygen (oxidizing agent) Carbon dioxide Water + 2O 2 CO 2 + Energy + 2 H 2 O becomes oxidized becomes reduced Reactants Products Figure 9.3
Background image of page 10
Oxidation of Organic Fuel Molecules During Cellular Respiration During cellular respiration Glucose is oxidized and oxygen is reduced C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy becomes oxidized becomes reduced
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
-Cellular respiration oxidizes glucose in a series of steps -Electrons stripped from glucose are not directly transferred to O 2 C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy becomes oxidized becomes reduced
Background image of page 12
Electrons from organic compounds Are first transferred to a Coenzyme Carrier NAD+: niacin= nicotinamide adenine dinuleotide NAD + + 2H NADH + H + FAD: riboflavin= flavin adenine dinucleotide FAD + 2H FADH 2 The H (electrons) come from the oxidation of glucose Loses 2 electrons (oxidized) gains 2 electrons (reduced)
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
NAD + H O O O O O O O O O O P P CH 2 CH 2 HO OH H H HO OH HO H H N + C NH 2 H N H NH 2 N N Nicotinamide (oxidized form) NH 2 + 2[H] (from food) Dehydrogenase Reduction of NAD + Oxidation of NADH 2 e + 2 H + 2 e + H + NADH O H H N C + Nicotinamide (reduced form) N Figure 9.4 NADH, the reduced form of NAD+ Passes the electrons to the electron transport chain
Background image of page 14
Image of page 15
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/02/2008 for the course BILD 1 taught by Professor Unk during the Spring '08 term at UCSB.

Page1 / 83

Lecture 8 Fermentation and Cellular Rspiration - Cellular...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online