Concepts in Biology : 6 1 Concepts in Biology E.D.Enger,
F.C.Ross &
D.B. Bailey
Tata McGraw Hill,
11th Edition, 2005
Biochemical Pathways : 6 2 Biochemical Pathways Chapter: 6
Lecture Number: 13
Outline : 6 3 Outline Energy and Organisms
Common Mechanisms Used in Processing Energy and Matter
Biochemical Pathways
Generating Energy in a Useful Form: ATP
Electron Transport
Proton Pump
Goals and Objectives : 6 4 Goals and Objectives Recognize that Organisms have several ways to obtain energy:
Autotrophs and Heterotrophs
Chemosynthetic and Photosynthetic Organisms
Recognize that there are metabolic processes basic to all organisms
Importance of ATP
ATP generation by Proton Pump
Cell and Energy : 6 5 Cell and Energy Potential Energy= Chemical bonds
Burning Wood?CO2+H2O+Potential Energy
Living Organisms:
Controlled Oxidation & Reduction Reactions
Energy = Power the Activities of Life.
Cells use Enzymes to process Energy and Matter : 6 6 Cells use Enzymes to process Energy and Matter Organisms obtain energy through enzyme-catalyzed biochemical reactions.
All Cells Need Energy : 6 7 All Cells Need Energy To do work
Making new molecules.
Building membranes and organelles.
Moving molecules in and out of the cell.
Movement.
6.1 Energy and Organisms : 6 8 6.1 Energy and Organisms Organisms
Autotrophs
Heterotrophs
AUTOTROPHS:
Photosynthetic autotroph: Use energy from sunlight .
Chemosynthetic autotroph: Use energy from inorganic chemical reaction .
HETEROTROPHS : 6 9 HETEROTROPHS Obtain energy from the chemical bonds of food molecules.
All organisms use cellular respiration.
Harvested energy = Make ATP
Energy Transformation : 6 10 Energy Transformation
Slide 11 : 6 11
6.1 Energy and Organisms : 6 12 6.1 Energy and Organisms Source of all Energy is Sun.
Photosynthesis: Energy converted to chemical energy.
Cellular Respiration: Release of chemical-bond energy from large organic molecules.
6.1 Energy and Organisms : 6 13 6.1 Energy and Organisms In Eukaryotic Cells: Biochemical processes carried out in specific organelles
Photosynthesis in Chloroplast
Cellular Respiration in Mitochondria
6.1 Energy and Organisms : 6 14 6.1 Energy and Organisms In Prokaryotic Cells:
Photosynthesis and cellular respiration within cytoplasm or on the inner surfaces of the cell membrane or on other special membranes
6.1 Energy and Organisms : 6 15 6.1 Energy and Organisms Cellular respiration is oxidation of organic molecules.
Some organisms require oxygen and others do not.
Aerobic Respiration (Oxygen is required).
Anaerobic Respiration (Oxygen is not required)
6.1 Energy and Organisms : 6 16 6.1 Energy and Organisms All Organisms must carry out cellular respiration.
All Organisms use organic molecules as source of Energy.
Wood? Burn? Large amount of heat and light
(Energy of Chemical Bonds)
Common mechanisms used in Processing Energy and Matter : 6 17 Common mechanisms used in Processing Energy and Matter In Living Organisms:
Energy is released in a series of small steps.
Each of the steps is controlled by an enzyme.
Each Step:
Enzyme
Substrate Product Product Acts As a
Enzyme
Substrate Product Product Acts As a ….
Slide 18 : 6 18
Common mechanisms used in Processing Energy and Matter : 6 19 Common mechanisms used in Processing Energy and Matter Series of such enzyme controlled reactions is called Metabolic/Biochemical Pathways.
Most Organisms use same metabolic pathways.
Example: Elephant, Petunia, Earthworm
BIOCHEMICAL (Metabolic) PATHWAYS : 6 20 BIOCHEMICAL (Metabolic) PATHWAYS What is Biochemical Pathway ?
Networks of Enzyme-Controlled Reactions performed in the process of obtaining energy
Catabolic Reactions: Breakdown of organic molecules & release of energy.
Anabolic Reactions: Synthesis of new organic molecules & require energy.
Biochemical pathways : 6 21 Biochemical pathways
What Is ATP? : 6 22 What Is ATP? ATP – adenosine triphosphate is a molecule made up of an adenine, ribose, and 3 phosphate groups. Adenine Ribose phosphate groups
Generating Energy:ATP : 6 23 Generating Energy:ATP Fuel to anabolic reactions
The bonds between the phosphates (high energy phosphate bonds) contain a lot of potential energy.
Breaking those bonds releases a lot of energy.
ATP - 1 phosphate = ADP
ADP – 1 phosphate = AMP
Adenosine Triphosphate (ATP) : 6 24 Adenosine Triphosphate (ATP) In living cells: Transfer of chemical energy by ATP.
ATP ? Broken ? Release of Chemical energy
Phosphorylation: Addition of Phosphate to a molecule
ADP + Addition of more Energy? Addition of P? ATP
Slide 25 : 6 25
Cell and Energy : 6 26 Cell and Energy Potential Energy= Chemical bonds
Food has stored potential energy.
Living Organisms: Prokaryotic cell and Eukaryotic cell
Food synthesis: Autotrophs
Cellular respiration: All cells
Cells use Enzymes to process Energy and Matter : 6 27 Cells use Enzymes to process Energy and Matter Source of all Energy is Sun. Source of all Energy is Sun.
Harvested energy = Make ATP : 6 28 Harvested energy = Make ATP In Eukaryotic Cells: Biochemical processes
Photosynthesis in Chloroplast
Cellular Respiration in Mitochondria
In Prokaryotic Cells:
Photosynthesis and cellular respiration
within cytoplasm or
on the inner surfaces of the cell membrane or on other special membranes
6.1 Energy and Organisms : 6 29 6.1 Energy and Organisms Cellular respiration
Aerobic Respiration
Anaerobic Respiration
Most Organisms use same metabolic pathways.
Biochemical Pathway: Catabolic Reactions& Anabolic reactions: : 6 30 Biochemical Pathway: Catabolic Reactions& Anabolic reactions: Adenine Ribose phosphate groups
Both ATP & ADP contain high energy bonds, are very unstable molecules and readily loose their Phosphate. : 6 31 Both ATP & ADP contain high energy bonds, are very unstable molecules and readily loose their Phosphate. This high energy bonds can be transferred to
Low Energy Molecule Released to Environment
AMP does not have high energy bond
In Cells, enzymes speedup the release of energy.
How Does ATP Work? : 6 32 How Does ATP Work? Energy is stored in the bond between the second and third phosphate group.
When the bond is broken, energy is released and ADP is formed. Adenine Ribose
How Does ATP Work? : 6 33 How Does ATP Work? When bond between the First and Second phosphate group is broken, energy is released and AMP is formed. Adenine Ribose
Making Energy : 6 34 Making Energy Cells make energy in two ways:
Photosynthesis – takes place in the chloroplasts.
Respiration – takes place in the mitochondria.
Slide 35 : 6 35
ATP Analog to Power Toys : 6 36 ATP Analog to Power Toys Each Battery contains right amount of energy to power the job.
Power drained, battery can be recharged numerous times before it must be recycled.
ATP: The power supply for Cell : 6 37 ATP: The power supply for Cell
ENERGY GENERATION : 6 38 ENERGY GENERATION Harvested energy from a chemical reaction/sunlight is stored :
Chemical reaction
Phosphate + an ADP ATP.
Sunlight
ATP is generated in Electron Transport Chain.
ELECTRON TRANSPORT CHAIN : 6 39 ELECTRON TRANSPORT CHAIN Electrons and Shells
Electrons + additional energy ? Move to a higher energy level.
Electrons? Give up energy? Fall back to their original position.
Energy is harnessed by molecules like cytochromes that capture excited electrons and is transferred to chemical reactions.
ELECTRON TRANSPORT : 6 40 ELECTRON TRANSPORT
ELECTRON TRANSPORT CHAIN : 6 41 ELECTRON TRANSPORT CHAIN Reactions are Oxidation-Reduction Reactions.
Molecules loose Electron=Loose Energy
Molecules gain Electron=Gain Energy
Electrons come from Hydrogen
(becomes H+).
ELECTRON Acceptors/Carriers : 6 42 ELECTRON Acceptors/Carriers NAD+,NADP+,FAD+ work in conjuction with an enzyme known as Coenzymes.
NAD+&NADP+=Vitamin Niacin
FAD+=Riboflavin
NAD+ + electron ? NADH ? Carriers of Hydrogen
Electron Transfer Reactions : 6 43 Electron Transfer Reactions Series of Oxidation and Reduction reactions in which each step results in transfer of small amount of energy from high energy molecule to lower energy molecule.
Electron Transfer tied to ATP Formation
PROTON PUMP : 6 44 PROTON PUMP Hydrogen= 1 Electron and 1 Proton
When e- is stripped off = H+ (Proton) is formed
High energy e- transferred to low energy state,
H+ (Protons) are pumped across membrane creating Proton gradient across the membrane.
Pressure created by high concentration of H+ (Protons) is released when
Protons flow through the pores in Membrane back to the side from which they were pumped.
PROTON PUMP : 6 45 PROTON PUMP Protons are pumped across a membrane
Creating a region with high concentration of protons on one side of a membrane.
The pressure created is released when the protons flow back into the cell through pores on the membrane.
As the protons pass through the membrane an ATPase enzyme speeds the formation of ATP by bonding ADP and P.
Electron transport and proton gradient : 6 46 Electron transport and proton gradient