Chapter_3_Cell_Metabolism_new

Chapter_3_Cell_Metabolism_new - Chapter 3 Cell Metabolism...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 3 Cell Metabolism I. Types of Metabolic Reactions Chemical Reactions Hydrolysis and Condensation Phosphorylation and Dephosphorylation Oxidation-Reduction Chemical Reactions Reactants (or substrates) Products A + B C + D Direction of reaction Forward Reverse Metabolic Reactions chemical reactions occurring in the body Catabolism = breakdown of organic molecules Release Energy Anabolism = synthesis of organic molecules Require Energy Metabolic Pathways A + X B C D + Y Initial substrate – A + X End Product substarte – D + Y Question: WHAT IS THE MINIMAL # OF ENZYMES YOU NEED TO BREAK DOWN SUBSTRATE A TO END PRODUCT? 5 ENZYMES Count in between letters (A – F) Sequence of enzymatic reactions that begins with initial substrate, progresses through intermediates and end with a final product. Oxidation-Reduction Reactions: OIL RIG Oxidation is loss o Removal of electrons (or H + ) o C 6 H 12 + 6 O 2 6 CO 2 + 6 H 2 O o Which is oxidized? Glucose forming water Reduction is Gain o Addiion of electrons (or H + )
Background image of page 1

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

View Full DocumentRight Arrow Icon
o What is reduced? Oxygen Energy Capacity to do work First Law of Thermodynamics Energy in universe (closed system) is constant Human body is an open system Humans give off heat by converting energy into heat Energy can be neither created nor destroyed Energy is recycled Energy Changes in Reactions Energy exchanged in all reactions Molecules possess energy Change in energy of a reaction = ΔE ΔE = E products – E reactants Energy-releasing Reaction If Energy in reactants > Energy in products Energy Released Downhill Reactant Products + Energy DELTA E is Negative Energy Change in Energy-releasing Reaction – fig 3.1a Energy-requiring Reaction – fig 3.1b If Energy in reactants < Energy in products Energy input required Uphill Reactants + Energy Products DELTA E is Positive Energy Change in Energy-requiring Reaction Types of Energy Kinetic energy – energy of motion Potential energy – stored energy Chemical energy – stored in bonds Potential and Kinetic Energy Direction of Reactions Energy releasing reactions ΔE is NEGATIVE
Background image of page 2
Occurs spontaneously Energy-requiring reactions ΔE is POSITIVE Does not occur spontaneously Requires input of energy Coupling Reactions: Energy from energy-releasing reaction used to drive energy-requiring reaction Energy of Equilibrium REACTANT PRODUCT Energy of molecules depends on concentration as well as structure At equilibrium, energy of reactants = energy of products No net change in concentration of products or reactants Law of Mass Action An increase in the concentration of reactants tends to push a reaction forward An increase i n the concentration of products tends to push a reaction in reverse Sometimes the body makes too much of “product A”; the body tries to keep
Background image of page 3

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

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/12/2011 for the course BIOL 2160 taught by Professor Kt during the Fall '08 term at LSU.

Page1 / 13

Chapter_3_Cell_Metabolism_new - Chapter 3 Cell Metabolism...

This preview shows document pages 1 - 4. Sign up to view the full document.

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