Upload
samuru
View
76
Download
0
Embed Size (px)
DESCRIPTION
LEQ: What is the role of ATP in cellular activities?. Cellular Energy Pages 72 to 75. Energy. What is energy? The capacity to do work What is Kinetic energy? Energy of motion Heat (thermal energy) is kinetic energy given off due the the movement of molecules What is Potential energy? - PowerPoint PPT Presentation
Citation preview
LEQ: What is the role of ATP in cellular activities?Cellular EnergyPages 72 to 75
EnergyWhat is energy?
◦The capacity to do workWhat is Kinetic energy?
◦Energy of motion◦Heat (thermal energy) is kinetic energy given
off due the the movement of moleculesWhat is Potential energy?
◦Stored energy that an object possess as a result of its location or structure
◦Chemical energy is potential energy available for release in a chemical reaction
Climbing up converts the kineticenergy of muscle movementto potential energy.
A diver has less potentialenergy in the waterthan on the platform.
Diving convertspotential energy tokinetic energy.
A diver has more potentialenergy on the platformthan in the water.
ThermodynamicsWhat is thermodynamics?
◦The study of energy transformation
◦Organisms are open systems
◦In an open system, energy and matter can be transferred between the system and its environment
The First Law of ThermodynamicsAccording 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
The Second Law of Thermodynamics
During every energy transfer or transformation, some energy is unusable, and is often lost as heat
According to the second law of thermodynamics: – Every energy transfer or
transformation increases the entropy (disorder) of the universe
(a) First law of thermodynamics (b) Second law of thermodynamics
Chemicalenergy
Heat CO2
H2O+
Biological Order and DisorderLiving things are ordered,
decreasing entropy - this requires an input of energy, increasing entropy….◦Building macromolecules
(dehydration synthesis) decreases entropy by organizing atoms into molecules, molecules into cells, etc…
◦In order to build / maintain organization requires an input of energy which increases entropy
Chemical ReactionsEndergonic Reactions
◦“Energy In”◦Require a net input of energy◦Rich in potential energy◦Photosynthesis – takes in energy to
produce sugar; energy stored in bonds
Fig. 8-6b
Energy
(b) Endergonic reaction: energy required
Progress of the reaction
Free
ene
rgy
Products
Amount ofenergyrequired(∆G > 0)
Reactants
Chemical ReactionsExergonic Reactions
◦“Energy Out”◦Chemical reactions that release
energy◦Cellular respiration – breaking bonds
of sugar to release energy
Fig. 8-6a
Energy
(a) Exergonic reaction: energy released
Progress of the reaction
Free
ene
rgy
Products
Amount ofenergyreleased(∆G < 0)
Reactants
Chemical ReactionsCellular Metabolism
◦Sum of all exergonic and endergonic reactions in a cell
◦Anabolic Pathways – consume energy to build complex molecules from simple ones (endergonic)
◦Catabolic Pathways – release energy by breaking down complex molecules into simple ones (exergonic)
Chemical ReactionsEnergy Coupling
◦The use of energy released from exergonic reactions to drive essential endergonic reactions
Adenosine Triphosphate
Phosphate groupsRibose
Adenine
Energy currency of the cellPowers nearly all cellular work
through energy coupling reactions
Fig. 8-9
Inorganic phosphate
Energy
Adenosine triphosphate (ATP)
Adenosine diphosphate (ADP)
P P
P P P
P ++
H2O
i
ATP – ADP Cycle
P iADP +
Energy fromcatabolism (exergonic,energy-releasingprocesses)
Energy for cellularwork (endergonic,energy-consumingprocesses)
ATP + H2O
Phosphorylation - adding a phosphate
Cells use ATP Three types of cellular work that
are powered by hydrolysis of ATP◦Cell Transport – Bringing materials
into cells◦Mechanical Work – muscle
contractions◦Chemical Work – macromolecule
synthesis
Fig. 8-11
(b) Mechanical work: ATP binds noncovalently to motor proteins, then is hydrolyzed
Membrane protein
P i
ADP+
P
Solute Solute transported
P i
Vesicle Cytoskeletal track
Motor protein Protein moved
(a) Transport work: ATP phosphorylates transport proteins
ATP
ATP