Unit 3: Cells

Chapter 8: Photosynthesis

Ms. PetrucciBiology

PhotosynthesiPhotosynthesiss

8-1 Energy & Life

Energy and LifeEnergy and Life

AutotrophsAutotrophs

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

AutotrophsAutotrophs

• Autotrophs Autotrophs include include organismsorganisms that make that make their own their own foodfood

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

EuglenaEuglena

HeterotrophsHeterotrophs

• Heterotrophs Heterotrophs are organisms are organisms that can NOT that can NOT make their own make their own foodfood

• Heterotrophs Heterotrophs can NOT can NOT directly use directly use the sunthe sun ’s ’s energyenergy

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 changed Energy can be changed from from one form to one form to anotheranother

• Energy can be stored in Energy can be stored in chemical bonds & then chemical bonds & then released laterreleased later Candles release energy as Candles release energy as

HEAT & LIGHTHEAT & LIGHT

ATP – Cellular ATP – Cellular EnergyEnergy

• Adenosine TriphosphateAdenosine Triphosphate• Contains two, high-energy phosphate Contains two, high-energy phosphate

bondsbonds• Also contains the nitrogen base adenine Also contains the nitrogen base adenine

& a ribose sugar& a ribose sugar

ADPADP

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

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

One phosphate bond has been removed

10

Sugar in ADP & ATPSugar in ADP & ATP

• Called ribose• Pentose sugar

• Also found on RNA

Importance of ATPImportance of ATP

Principal Compound Used To Store Energy In Living Organisms

Storing Energy• When a cell has energy available, it can store small

amounts of it by adding a phosphate group to ADP molecules, producing ATP.

Releasing Energy From Releasing Energy From ATPATP

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

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

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

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

Releasing Energy From ATPReleasing Energy From ATP

• AddingAdding A Phosphate A Phosphate Group To ADP stores Group To ADP stores Energy in ATPEnergy in ATP

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

• The characteristics of The characteristics of ATP make it ATP make it exceptionally useful as exceptionally useful as the basic energy source the basic energy source of all cells.of all cells.

Lose

Gain

Cells Using Biochemical Cells Using Biochemical EnergyEnergy

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

respiration• All other cellular

reactions

More on ATPMore on ATP

• Cells Have Enough ATP To Cells Have Enough ATP To Last For A Last For A Few SecondsFew Seconds

• ATP must ATP must constantlyconstantly be be mademade

• ATP ATP Transfers Energy Very Transfers Energy Very WellWell

• ATP Is ATP Is NOTNOT Good At Energy Good At Energy StorageStorage

GlucoseGlucose

• Glucose is a Glucose is a monosaccharidemonosaccharide

• CC 66 HH 1 21 2 OO 66

• One Molecule of One Molecule of glucose Stores glucose Stores 90 90 TimesTimes More Chemical More Chemical Energy Than One Energy Than One Molecule of ATPMolecule of ATP