Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions...
-
Upload
lester-arnold -
Category
Documents
-
view
228 -
download
0
Transcript of Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions...
![Page 1: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/1.jpg)
Chapter 8An Introduction to Metabolism
![Page 2: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/2.jpg)
Metabolism
• Metabolism is the sum of all chemical reactions in your body.
• If a reactions breaks things down, it is catabolic
• If a reaction builds things up, it is anabolic
![Page 3: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/3.jpg)
Energy
• Energy is the capacity to cause change.• Energy of motion is kinetic energy• Energy that is stored is potential energy• Potential energy that is released during a
chemical reaction is chemical energy
![Page 4: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/4.jpg)
The Laws of Energy Transformation
• Thermodynamics is the study of energy transformations
• A closed system is a system that exchanges only energy with its surroundings, not matter. Putting a lid on the saucepan makes the saucepan a closed system.
• An open system is a system which continuously interacts with its environment or surroundings
• Organisms are open systems
![Page 5: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/5.jpg)
The First Law of Thermodynamics
• According to the first law of thermodynamics, the energy of the universe is constant:
• – Energy can be transferred and transformed, but it cannot be created or destroyed
• The first law is also called the principle of conservation of energy
![Page 6: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/6.jpg)
Energy is released or consumed
• In an exergonic reaction energy is released.
• When you break things down, you release energy
• All catabolic reactions are exergonic
• Cellular respiration is exergonic.
• These are spontaneous reactions
• Delta G (a measure of free energy) is negative
![Page 7: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/7.jpg)
Energy is released or consumed
• In an endergonic reaction energy is absorbed.
• When you build things, you need energy
• All anabolic reactions are endergonic
• Photosynthesis is endergonic
• These are non-spontaneous reactions
• Delta G is positive
![Page 8: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/8.jpg)
Making and breaking bonds
• Making bonds is called dehydration synthesis. You remove water to make a new bond.
• Breaking bonds is called hydrolysis. You add water to break a bond.
![Page 9: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/9.jpg)
Introducing ATP
• ATP is adenosine triphosphate
• It is composed of a nitrogenous base called adenine, a ribose sugar, and a chain of 3 phosphate groups
• Energy is stored in the bonds between the phosphate groups.
• When a bond is broken between the Ps, it releases energy
![Page 10: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/10.jpg)
Hydrolysis of ATP
• The bonds between the phosphate groups of ATP’s tail can be broken by hydrolysis
• Energy is released from ATP when the terminal phosphate bond is broken
• This release of energy comes from the chemical change to a state of lower free energy, not from the phosphate bonds themselves
![Page 11: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/11.jpg)
The Regeneration of ATP
• ATP is a renewable resource that is regenerated by addition of a phosphate group to adenosine diphosphate (ADP)
• The energy to phosphorylate ADP comes from catabolic reactions in the cell
• The chemical potential energy temporarily stored in ATP drives most cellular work
![Page 12: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/12.jpg)
Enzymes!
• Enzymes are proteins. They are catalysts that speed up chemical reactions by lowering the amount of energy needed for those reactions to start (activation energy)
![Page 13: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/13.jpg)
Enzyme terms
• What an enzyme binds to and acts on is called the substrate.
• The place where the enzyme binds is the active site.
• Enzymes are specific and only fit to their own substrate like a key into a lock
• Enzymes are reusable and are used over and over
![Page 14: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/14.jpg)
Factors affecting enzymes
• 1. Temperature
• 2. pH
• 3. Salinity
• Each enzyme has an optimal pH and temperature in which it can function
![Page 15: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/15.jpg)
Factors affecting enzymes
• Some enzymes need helpers:
• Cofactors are INORGANIC and bind to the enzymes to make them work (zinc, iron, copper, minerals)- no carbon
• Coenzymes are ORGANIC and bind to the enzyme to make them work (vitamins)
![Page 16: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/16.jpg)
Factors affecting enzymes
• Inhibitors block enzyme action
• Competitive inhibitors bind to the active site of the substrate so that the enzyme can’t get in
• Non-competitive inhibitors bind somewhere on the substrate, changing the shape of the active site, so enzymes no longer fit
![Page 17: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/17.jpg)
Allosteric regulation
• Allosteric regulation may either inhibit or stimulate an enzyme’s activity
• Allosteric regulation occurs when a regulatory molecule binds to a protein at one site and affects the protein’s function at another site
![Page 18: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/18.jpg)
Feedback Inhibition
• In feedback inhibition, the end product of a metabolic pathway shuts down the pathway
• This type of inhibition is done as a regulatory mechanism to meet the metabolic needs of the cell or organism. Mechanisms, such as cellular respiration, use feedback inhibition.
![Page 19: Chapter 8 An Introduction to Metabolism. Metabolism Metabolism is the sum of all chemical reactions in your body. If a reactions breaks things down, it.](https://reader035.fdocuments.in/reader035/viewer/2022081504/5697bfaa1a28abf838c9a3bb/html5/thumbnails/19.jpg)
Specific Localization of Enzymes Within the
Cell• Structures within the
cell help bring order to metabolic pathways
• Some enzymes act as structural components of membranes
• In eukaryotic cells, some enzymes reside in specific organelles; for example, enzymes for cellular respiration are located in mitochondria
Mitochondria