Lec7notescomplete

Lec7notescomplete - Bio1A Dr. McCray Lec 7 Complete Notes 1...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Bio1A Dr. McCray Lec 7 Complete Notes 1 Chapter 9 Cellular Respiration: Harvesting Chemical Energy Energy Flow a Energy flows into an ecosystem as sunlight and leaves as heat a Photosynthesis generates oxygen and organic molecules , which are used in cellular respiration a Cells use chemical energy stored in organic molecules to regenerate ATP, which powers work Fig. 9-2 Catabolic Pathways and Production of ATP a Several processes are central to cellular respiration and related pathways a The breakdown of organic molecules is exergonic a Fermentation is a partial degradation of sugars that occurs without oxygen a Cellular respiration consumes oxygen and organic molecules and yields ATP a Although carbohydrates, fats, and proteins are all consumed as fuel, it is helpful to trace cellular respiration with the sugar glucose: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy (ATP + heat) Redox Reactions: Oxidation and Reduction a The transfer of electrons during chemical reactions releases energy stored in organic molecules a This released energy is ultimately used to synthesize ATP Redox a Chemical reactions that transfer electrons between reactants are called oxidation-reduction reactions, or redox reactions a In oxidation , a substance loses electrons, or is oxidized a In reduction , a substance gains electrons, or is reduced (the amount of positive charge is reduced) Redox Terminology a The electron donor is called the reducing agent a The electron receptor is called the oxidizing agent a Some redox reactions do not transfer electrons but change the electron sharing in covalent bonds a An example is the reaction between methane and oxygen Fig. 9-3 Oxidation of Organic Fuel Molecules During Cellular Respiration a During cellular respiration, the fuel (such as glucose) is oxidized and oxygen is reduced : Bio1A Dr. McCray Lec 7 Complete Notes 2 Stepwise Energy Harvest via NAD + a In cellular respiration, glucose and other organic molecules are broken down in a series of steps a Electrons from organic compounds are usually first transferred to NAD + , a coenzyme a As an electron acceptor, NAD + functions as an oxidizing agent during cellular respiration a Each NADH (the reduced form of NAD + ) represents stored energy that is tapped to synthesize ATP Fig. 9-4 Electron Transport Chain...
View Full Document

This note was uploaded on 09/16/2010 for the course BIO 1A taught by Professor Mccray during the Fall '09 term at Merritt College.

Page1 / 5

Lec7notescomplete - Bio1A Dr. McCray Lec 7 Complete Notes 1...

This preview shows document pages 1 - 3. Sign up to view the full document.

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