Cells Cells andand

EnergyEnergyPhotosynthesis & Photosynthesis &

Cellular RespirationCellular Respiration

Cells Lecture IIICells Lecture III

Biology Standards Covered

1f ~ students know usable energy is 1f ~ students know usable energy is captured from sunlight by captured from sunlight by chloroplastschloroplasts and is and is stored from the synthesis of stored from the synthesis of sugarsugar from from carbon dioxidecarbon dioxide

1g ~ students know the role of the 1g ~ students know the role of the mitochondriamitochondria in making in making stored chemical-stored chemical-bond energybond energy available to cells by completing available to cells by completing the breakdown of the breakdown of glucoseglucose to to carbon dioxidecarbon dioxide

*1i ~ students know how *1i ~ students know how chemiosmotic chemiosmotic gradientsgradients in the in the mitochondriamitochondria and and chloroplastschloroplasts store energy for store energy for ATPATP production production

PhotosynthesisPhotosynthesis There are only two types of There are only two types of

organisms on this planetorganisms on this planet ProducersProducers – living things that – living things that

make their own food as well as make their own food as well as food for other living thingsfood for other living things

ConsumersConsumers – living things that – living things that rely upon consuming another rely upon consuming another organism for food (energy)organism for food (energy)

What are you?What are you?

PhotosynthesisPhotosynthesis ProducersProducers

An example of a An example of a producer would be a producer would be a plant and how it plant and how it “makes” food could be “makes” food could be through a process through a process known as known as photosynthesisphotosynthesis

This takes place in the This takes place in the chloroplastchloroplast organelle organelle inside of a plant cellinside of a plant cell

PhotosynthesisPhotosynthesis PhotosynthesisPhotosynthesis – is the – is the

process of using energy process of using energy from the sun to convert from the sun to convert COCO22 and and HH22OO into into chemical chemical energyenergy in the form of in the form of sugarssugars Sunlight radiates the Earth Sunlight radiates the Earth

as as visiblevisible light that we see light that we see and is made up of many and is made up of many different colors different colors (ROYGBIV)(ROYGBIV) Red, Orange, Yellow, Green, Red, Orange, Yellow, Green,

Blue, Indigo, and VioletBlue, Indigo, and Violet

PhotosynthesisPhotosynthesis

ChlorophyllChlorophyll is a molecule in plants is a molecule in plants that that absorbsabsorbs visible light from the sun visible light from the sun There are two typesThere are two types ( (Chlorophyll Chlorophyll aa and and

Chlorophyll Chlorophyll bb ) ) Together Together they absorb mostly red and they absorb mostly red and

blueblue wavelengths of light while wavelengths of light while “reflecting” some yellow and much of the “reflecting” some yellow and much of the greengreen This is why you see plant leaves as This is why you see plant leaves as “green”“green”

because of the ‘reflected’ colorbecause of the ‘reflected’ color

PhotosynthesisPhotosynthesis

Inside of the chloroplast are Inside of the chloroplast are twotwo structures important to structures important to photosynthesisphotosynthesis GranaGrana – are stacks of – are stacks of

membranes that look like a membranes that look like a stack of pennies surrounded stack of pennies surrounded by compartments called by compartments called thylakoidsthylakoids

StromaStroma – is the – is the fluid fluid surrounding the granasurrounding the grana inside inside of the chloroplastof the chloroplast

PhotosynthesisPhotosynthesis There are There are twotwo stages to Photosynthesis stages to Photosynthesis

Light-dependent reactions Light-dependent reactions (First)(First) ChlorophyllChlorophyll absorbs energy from sunlight and absorbs energy from sunlight and

energy is transferred along energy is transferred along thylakoidsthylakoids, Water is , Water is broken down and Oxygen is producedbroken down and Oxygen is produced

Energy that is carried along Energy that is carried along thylakoidsthylakoids is is transferred in molecules of ATPtransferred in molecules of ATP

Light-independent reactions Light-independent reactions (Second)(Second) Carbon DioxideCarbon Dioxide is added to a cycle of chemical is added to a cycle of chemical

reactions building larger molecules of sugars reactions building larger molecules of sugars Energy, Energy, ATPATP, from the , from the light-dependent reactionlight-dependent reaction is is

used to form these simple sugarsused to form these simple sugars

Photosynthesis in a Photosynthesis in a ChloroplastChloroplast

C6H12O6 is

Glucose, a simple sugar that feeds all living things

CO2 (gas) is used to

make the sugar Glucose

Photosynthesis in Photosynthesis in ChloroplastsChloroplasts

Cellular RespirationCellular RespirationThe The mitochondrionmitochondrion and its and its

role in providing plants role in providing plants and animals with and animals with energyenergy

Chemical Chemical EnergyEnergy for for OrganismsOrganisms

ATPATP – Adenosine – Adenosine triphosphatetriphosphate An energy rich molecule An energy rich molecule

that provides all living that provides all living things with energy for things with energy for growth, repair, and growth, repair, and maintenancemaintenance

ADPADP – Adenosine – Adenosine diphosphatediphosphate Energy Energy comes fromcomes from the the

release of the 3release of the 3rdrd phosphate of ATPphosphate of ATP

This creates ADPThis creates ADP

What is ATP?

ATP is molecule ATP is molecule that that acts likeacts like a a chemical form of chemical form of electricity for electricity for all all living thingsliving things!!

Without ATP, you Without ATP, you could not move, could not move, think, breathe, or think, breathe, or grow!grow!

What is Cellular Respiration?

Cellular respirationCellular respiration is is when when chemical energy is released from chemical energy is released from sugars and other carbon based sugars and other carbon based molecules to make ATP ~ when molecules to make ATP ~ when oxygen is presentoxygen is present

This means that cellular This means that cellular respiration is respiration is aerobicaerobic in that it in that it needs oxygenneeds oxygen to take place to take place

Energy Production’s 2 StagesEnergy Production’s 2 StagesGlycolysis & Cellular RespirationGlycolysis & Cellular Respiration

How does it work? Cellular RespirationCellular Respiration (stage 2) (stage 2)

takes place in a takes place in a mitochondrionmitochondrion Some cells have severalSome cells have several

IMPORTANT! ~ IMPORTANT! ~ BeforeBefore cellular cellular respiration can take place ~ respiration can take place ~ Food molecules MUST be broken Food molecules MUST be broken

down into simpler molecules down into simpler molecules The break down of The break down of glucoseglucose into (2) into (2)

3~Carbon Sugars is called 3~Carbon Sugars is called GlycolysisGlycolysis Glycolysis Glycolysis occurs in theoccurs in the cytoplasmcytoplasm

Glycolysis

Glucose 2 Pyruvic

acid

To the electron transport

chain

* Glycolysis is anaerobic because it does NOT require oxygen to take place! This This happens in the cytoplasmhappens in the cytoplasm

2 ATP are used to “start” Glycolysis and 4 ATP are made in the second stage. That means Glycolysis yields a “net” of +2 ATP

Cellular Respiration happens in the Mitochondrion

2 Pyruvate molecules

from glycolysis

go into Stage 1

The Kreb’s Cycle aka. Citric Acid Cycle

STAGE 1: STAGE 1: The Krebs CycleThe Krebs Cycle During stage 1 the (2) 3~Carbon During stage 1 the (2) 3~Carbon

pyruvate molecules from pyruvate molecules from Glycolysis Glycolysis enter the mitochondria enter the mitochondria

These molecules undergo a series of These molecules undergo a series of chemical reactions and a small chemical reactions and a small amount of ATP is produced (2 ATP amount of ATP is produced (2 ATP Molecules)Molecules)

The The waste productwaste product of the Kreb’s Cycle of the Kreb’s Cycle is 6 COis 6 CO22 (Carbon dioxide) molecules (Carbon dioxide) molecules

EnergyEnergy is transferred to “power” is transferred to “power” Stage 2 of Cellular RespirationStage 2 of Cellular Respiration

The Kreb’s Kreb’s CycleCycle

generates NADHNADH and

FADHFADH22 that are fed into stage 2 ~ Electron Electron

Transfer Transfer PhosphorylatioPhosphorylatio

nn

Stage 2 of Cellular Respiration

Stage 2: Stage 2: Electron Transfer Electron Transfer PhosphorylationPhosphorylation Energy from Energy from GlycolysisGlycolysis and the and the Krebs CycleKrebs Cycle

enter Stage 2 to “power” the reactionsenter Stage 2 to “power” the reactions NADHNADH and and FADHFADH22 are “spent” to create a are “spent” to create a

H+H+ ion gradient inside of a mitochondrion ion gradient inside of a mitochondrion When these protons, H+ ions, “rush back When these protons, H+ ions, “rush back

in” to the mitochondrion, it generates in” to the mitochondrion, it generates ATPATP!! Stage 2 makes 32 ATP molecules!Stage 2 makes 32 ATP molecules!

Glycolysis and the Kreb’s Cycle each only made Glycolysis and the Kreb’s Cycle each only made 22

Cellular Respiration & Glycolysis

H+ Proton Gradient Formation

The inner and outer compartments of the mitochondrion are where the H+ ions are “pumped” and allowed back in for

ATP generation

H+ Proton Gradient Formation

ATP Generation through ATP Synthase