ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic...
-
Upload
horace-hutchinson -
Category
Documents
-
view
224 -
download
0
description
Transcript of ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic...
![Page 1: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/1.jpg)
ENERGY AND METABOLISMCH 8
![Page 2: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/2.jpg)
• Metabolism: all of an organism’s chemical reactions
• Metabolic pathways: series of chemical reactions
• Catabolic pathways: break down large molecules releasing energy
• Anabolic pathways: build large molecules using energy
![Page 3: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/3.jpg)
I. Energy and living things
• Energy = the ability to cause change• Kinetic energy = energy of motion• Potential energy = stored energy• Chemical energy: potential energy available
for release in chemical reactions• Thermal energy: kinetic energy due to
movement of atoms•
![Page 4: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/4.jpg)
A. Laws of Energy Transformations• Thermodynamics: study of energy
transformations1. 1st Law of Thermodynamics: energy can’t be created or destroyed only transformed or transferred
![Page 5: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/5.jpg)
2. 2nd Law of Thermodynamics: every energy transfer or transformation increases entropy (disorder) of universeduring energy transfers or transformations, energy is often lost as heat or other unusable form
![Page 6: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/6.jpg)
• energy enters an ecosystem as light and exits as heat
• Organisms are ordered and have low entropy. But they use large molecules thus increasing entropy of universe by releasing heat
![Page 7: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/7.jpg)
B. Free energy and chemical reactions
• Free Energy = the energy available to do work• All molecules have a certain amount of free
energy = G• All chemical reactions result in a change in
free energy = ∆G• ∆G = Gproduct – G reactant
![Page 8: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/8.jpg)
![Page 9: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/9.jpg)
1. Endergonic reactions
• Are not spontaneous• Require input of energy to occur• ∆G is positive• Products have a greater G than reactants• Example: glucose production during
photosynthesis•
![Page 10: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/10.jpg)
2. Exergonic reactions
• Are spontaneous• Release energy• ∆G is negative• Products have lower G than reactants• Example glucose breakdown during
respiration•
![Page 11: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/11.jpg)
II. ATP: The energy molecule
• The chief energy molecule for all cells is ATP• ATP is used for:– Chemical work– Transport work– Mechanical work
• To do work, cells couple exergonic processes to drive endergonic ones
![Page 12: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/12.jpg)
A. Structure and hydrolysis of ATP
• Made of a 5 carbon ribose sugar, three phosphates and an adenine base
• When the last phosphate bond in ATP is broken by hydrolysis a HUGE amount of energy is released
![Page 13: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/13.jpg)
B. How ATP performs work
• Hydrolysis of ATP is exergonic• This energy released is used to drive an
endergonic reaction
![Page 14: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/14.jpg)
![Page 15: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/15.jpg)
C. Regeneration of ATP
• Forming ATP is endergonic• It is coupled to a catabolic reaction
![Page 16: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/16.jpg)
III. Enzymes and chemical Reactions
![Page 17: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/17.jpg)
A. Activation Energy• The input energy needed to get a reaction started• The existing bonds in a molecule are stable• In order to break those bonds to form new ones, an
input of energy (activation energy) is required
![Page 18: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/18.jpg)
B. Enzymes
Protein catalysts that speed up chemical reactions by lowering the activation energy
![Page 19: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/19.jpg)
C. Structure of an enzyme
• Usually globular in shape• Has an active site where substrate binds and
chemical reaction occurs. • Once substrate enters active site, induced fit
allows chemical reaction to occur• Many have allosteric site that regulates
activity at the active site
![Page 20: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/20.jpg)
![Page 21: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/21.jpg)
• The shape of the enzyme (its active site and allosteric site) is determined by the way that enzyme folds
• The primary structure of the enzyme determines its secondary and tertiary structure which determines shape and ultimately function
• If the shape of the enzyme is altered then it can no longer carry out chemical reactions
![Page 22: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/22.jpg)
Mechanism of enzyme action:
http://www.stolaf.edu/people/giannini/flashanimat/enzymes/enzyme.swf http://highered.mcgraw-hill.com/sites/0072943696/student_view0/chapter2/animation__how_enzymes_work.html
![Page 23: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/23.jpg)
D. Factors affecting enzyme activity
The more substrate, the faster the rate of reaction due to increased rate of collision with active site, till all active sites are occupied with substrate and the rate of reaction plateaus
1. Amount of substrate:
![Page 24: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/24.jpg)
2. Temperatureoptimal temperature: where rate of reaction is greatest• Below the optimal temp:
Increasing temp increases molecular motion and rate of collision with active site
• Above the optimal temp:Weak interactions holding enzyme’s shape break and enzyme unfolds
http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter2/animation__protein_denaturation.html
![Page 25: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/25.jpg)
3. pH• Below or above the
optimal pH, charges on the ionic amino acids are altered.
• This alters the ionic interactions in the active site
• The active site loses its shape and unfolds
![Page 26: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/26.jpg)
4. Inhibitors
what would happen if more substrate was added to reaction with competitive inhibitor? Noncompetitive inhibitor?
http://bcs.whfreeman.com/thelifewire/content/chp06/0602001.html
![Page 27: ENERGY AND METABOLISM CH 8. Metabolism: all of an organism’s chemical reactions Metabolic pathways: series of chemical reactions Catabolic pathways: break.](https://reader035.fdocuments.net/reader035/viewer/2022081515/5a4d1b167f8b9ab059991c97/html5/thumbnails/27.jpg)
IV. Allosteric Regulation of Metabolic Pathways
Product becomes allosteric inhibitor and shuts off an early enzyme in the pathway
http://highered.mcgraw-hill.com/sites/0072943696/student_view0/chapter2/animation__feedback_inhibition_of_biochemical_pathways.html