Cellular Energy

How organisms obtain their energy

Transformation of energy

What is energy?•The ability to do work

Thermodynamics•The study of the flow and transformation of energy in the universe

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EnergyEnergy• Energy Takes Many Energy Takes Many

Forms such as Forms such as light, light, heat, electrical, heat, electrical, chemical, mechanicalchemical, mechanical

• Energy can be Energy can be changed from changed from one one form to anotherform to another

• Energy can be stored Energy can be stored in chemical bonds & in chemical bonds & then released laterthen released later

Candles release energy as HEAT & LIGHTCandles release energy as HEAT & LIGHT

Laws of Thermodynamics

First LawLaw of Conservation of energy-Energy can not be created or

destroyed. It will only be converted from one form to another

Example: Stored energy in food in converted to chemical energy when you eat and mechanical energy when you kick a ball

Law of thermodynamics

Second LawEntropy increasesEnergy cannot be converted without the loss of usable energyEnergy that is lost is generally converted to

thermal (Heat) energyEntropy is the measure of disorder, or

unusable energy, in a system

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AutotrophsAutotrophs

Plants and Plants and some other some other types of types of organisms that organisms that contain contain chlorophyllchlorophyll are are able to use able to use light energy light energy from the sunfrom the sun to produce to produce food.food.

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AutotrophsAutotrophs• Autotrophs Autotrophs

include include organismsorganisms that make that make their own foodtheir own food

• Autotrophs Autotrophs can use the can use the sun’s energy sun’s energy directlydirectly

EuglenaEuglena

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HeterotrophsHeterotrophs• HeterotrophHeterotroph

s are s are organisms organisms that can NOT that can NOT make their make their own foodown food

• HeterotrophHeterotrophs can NOT s can NOT directly use directly use the sun’s the sun’s energyenergy

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ATP – Cellular EnergyATP – Cellular Energy• Adenosine TriphosphateAdenosine Triphosphate• Contains two, high-energy Contains two, high-energy

phosphate bondsphosphate bonds• Also contains the nitrogen base Also contains the nitrogen base

adenine & a ribose sugaradenine & a ribose sugar

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ADPADP• Adenosine DiphosphateAdenosine Diphosphate• ATP releases ATP releases energyenergy, a , a free free

phosphate,phosphate, & & ADPADP when cells when cells take energy from ATPtake energy from ATP

One phosphate bond has been removed

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Sugar in ADP & ATPSugar in ADP & ATP

• Called ribose

• Pentose sugar

• Also found on RNA

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Importance of ATPImportance of ATP

Principal Compound Used To Store Energy In Living Organisms

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Releasing Energy From Releasing Energy From ATPATP

• ATP is constantly being ATP is constantly being used used and remade by cellsand remade by cells

• ATP provides all of the energy ATP provides all of the energy for for cell activitiescell activities

• The high energy phosphate The high energy phosphate bonds can be bonds can be BROKENBROKEN to to release release energyenergy

• The process of releasing ATP’s The process of releasing ATP’s energy & reforming the molecule energy & reforming the molecule is called is called phosphorylationphosphorylation

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Releasing Energy From Releasing Energy From ATPATP

• AddingAdding A A Phosphate Phosphate Group To ADP Group To ADP stores Energy in stores Energy in ATPATP

• RemovingRemoving A A Phosphate Phosphate Group From ATP Group From ATP Releases Energy Releases Energy & forms ADP& forms ADP

Loose

Gain

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Cells Using Biochemical Cells Using Biochemical EnergyEnergy

Cells Use ATP For:• Active transport• Movement• Photosynthesis• Protein Synthesis• Cellular

respiration• All other cellular

reactions

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More on ATPMore on ATP• Cells Have Enough ATP Cells Have Enough ATP

To Last For A To Last For A Few Few SecondsSeconds

• ATP must ATP must constantlyconstantly be be mademade

• ATP ATP Transfers Energy Transfers Energy Very WellVery Well

• ATP Is ATP Is NOTNOT Good At Good At Energy StorageEnergy Storage