Photosynthesis & Cellular Respiration. Energy and Living Things Where does energy in food come from? Directly or indirectly, almost all energy comes

PhotosynthesiPhotosynthesiss& &

Cellular Cellular RespirationRespiration

Energy and Living Things Energy and Living Things

Where does energy in Where does energy in food come from?food come from?

Directly or indirectly, Directly or indirectly, almost all energy almost all energy comes from the comes from the sunsun

MetabolismMetabolism

MetabolismMetabolism involves either using involves either using energy to energy to buildbuild molecules or molecules or breakbreak downdown molecules in which molecules in which energy is stored.energy is stored.

PhotosynthesisPhotosynthesis

Photosynthesis- Photosynthesis- light light energy is changed energy is changed into chemical into chemical energy (sun to energy (sun to sugar).sugar).

AutotrophsAutotrophs

Autotrophs Autotrophs organisms that can organisms that can use energy from the sun use energy from the sun through photosynthesisthrough photosynthesis

Examples: Examples: plants, algae, some plants, algae, some protists and bacteriaprotists and bacteria

HeterotrophsHeterotrophs

Heterotrophs Heterotrophs organisms that organisms that get energy from food instead get energy from food instead of directly from the sunof directly from the sun

Examples: Examples: humans, animals, humans, animals, fungus, some protists and fungus, some protists and bacteriabacteria

Flow of Energy Flow of Energy

****Use different organisms!!!!****Use different organisms!!!!

Cellular RespirationCellular Respiration

Cellular Respiration- Cellular Respiration- METABOLIC PROCESS METABOLIC PROCESS SIMILAR TO BURNING FUEL; SIMILAR TO BURNING FUEL; RELEASE OF ATP (TAKES RELEASE OF ATP (TAKES PLACE IN MITOCHONDRIA)PLACE IN MITOCHONDRIA)

ATP- ATP- Adenosine Adenosine TriphosphateTriphosphate ATP is made up of:ATP is made up of:

1 1 adenineadenine, ,

1 1 riboseribose, and , and

3 3 phosphatesphosphates.. When the outer When the outer

phosphate group phosphate group detachesdetaches from from ATP, ATP, energyenergy is is releasedreleased..

ATP- ATP- Adenosine Adenosine TriphosphateTriphosphate

Flow of EnergyFlow of EnergyWhen you eat a hamburger, you get When you eat a hamburger, you get

energy from the energy from the sunsun (indirectly). The (indirectly). The beef comes from a cow that ate beef comes from a cow that ate grassgrass. The bun, lettuce, and . The bun, lettuce, and tomatoes all come from plantstomatoes all come from plants

Stages of Photosynthesis Stages of Photosynthesis

Stage 1 (Absorption of Light Energy):Stage 1 (Absorption of Light Energy):

Energy is captured from sunlight.Energy is captured from sunlight.


Stage 2 (Conversion of Light Energy):Stage 2 (Conversion of Light Energy):

LIGHT ENERGY IS LIGHT ENERGY IS CONVERTED TO CHEMICAL CONVERTED TO CHEMICAL ENERGY WHICH IS STORED ENERGY WHICH IS STORED IN ATP.IN ATP. THE ENERGY THE ENERGY CARRIER MOLECULE IS CARRIER MOLECULE IS NADPH.NADPH.


Stage 3 (Storage of Energy):Stage 3 (Storage of Energy):Chemical energy stored in ATP and Chemical energy stored in ATP and NADPH powers the formation of NADPH powers the formation of organic compounds using COorganic compounds using CO22..

***Stage 3 can happen in absence of ***Stage 3 can happen in absence of sunlight IF stage 1 & 2 have occuredsunlight IF stage 1 & 2 have occured

Equation for Equation for PhotosynthesisPhotosynthesis

6 6 COCO22 + 6 + 6 HH22OO CC66HH1212OO66 + 6 + 6 OO22

Light

Glucose

(sugar)

PhotosynthesisPhotosynthesis

Stage 1: Stage 1: Absorption of Absorption of LightLight

Sunlight contains a mixture of all the Sunlight contains a mixture of all the wavelengths wavelengths (colors)(colors) of visible light. of visible light.

Pigments- contain Pigments- contain lightlight absorbing absorbing substances. The color an object is substances. The color an object is tells us what color is reflected by that tells us what color is reflected by that object and is not object and is not absorbedabsorbed..


ChlorophyllChlorophyll is the main pigment involved is the main pigment involved in photosynthesis. It absorbs in photosynthesis. It absorbs blueblue and and redred and reflects and reflects greengreen and and yellowyellow. .

The reflection of The reflection of greengreen light makes many light makes many plants look plants look greengreen, especially , especially leavesleaves. . The leaves are where most The leaves are where most photosynthesisphotosynthesis occurs. occurs.


2 types of chlorophyll:2 types of chlorophyll:

chlorophyll achlorophyll a and and chlorophyll bchlorophyll b Yellow pigments are Yellow pigments are carotenoidscarotenoids (Carotenoids are responsible for fall (Carotenoids are responsible for fall

colors in leaves and the color of fruits, colors in leaves and the color of fruits, vegetables, and flowers.)vegetables, and flowers.)

Stage 1: Stage 1: Absorption Absorption of Lightof Light

OxygenOxygen is produced in the 1 is produced in the 1stst step of step of photosynthesis. Where does this photosynthesis. Where does this happen?happen?

Leaf Chloroplast ThylakoidsLeaf Chloroplast Thylakoids

Draw a Draw a chloroplast with chloroplast with

thylakoids thylakoids labeled.labeled.

When light is absorbed by the When light is absorbed by the thylakoidsthylakoids, , energy is transferred to energy is transferred to electronselectrons in in chlorophyll . The electrons get chlorophyll . The electrons get “excited”“excited” and and jumpjump from chlorophyll to from chlorophyll to other nearby other nearby moleculesmolecules in the thylakoid in the thylakoid membrane. The electrons are used to membrane. The electrons are used to power the power the 22ndnd step of photosynthesis. step of photosynthesis.


The excited electrons are replaced by The excited electrons are replaced by electronselectrons from from waterwater molecules. molecules.

The water molecules are The water molecules are splitsplit by an by an enzymeenzyme inside the thylakoid.inside the thylakoid.

HH++ electrons are taken by the chlorophyll, leaving electrons are taken by the chlorophyll, leaving oxygenoxygen..


Stage 2: Stage 2: Conversion Conversion of of LightLight

An excited An excited electronelectron is passed along the is passed along the membrane like a membrane like a ballball being passed down being passed down a a lineline of people of people..

ETC (Electron Transport Chain)- ETC (Electron Transport Chain)- a a series of molecules through which series of molecules through which excited electrons are passed along a excited electrons are passed along a thylakoid membranethylakoid membrane

Stage 1 & 2 Summary:Stage 1 & 2 Summary: (Light Dependent)(Light Dependent)

Pigment molecules in the thylakoids of Pigment molecules in the thylakoids of chloroplasts absorb light energy. chloroplasts absorb light energy. Electrons in the pigments are Electrons in the pigments are excited by light and move through excited by light and move through ETC’s in the thylakoid membranesETC’s in the thylakoid membranes..

Continued on next slideContinued on next slide

Stage 1 & 2 Summary:Stage 1 & 2 Summary: (Light Dependent)(Light Dependent)

These electrons are replaced by These electrons are replaced by electrons from Helectrons from H22O split by an O split by an enzyme. Oxygen atoms from Henzyme. Oxygen atoms from H22O O molecules combine to form oxygen molecules combine to form oxygen gas (Ogas (O2)2). Hydrogen ions accumulate . Hydrogen ions accumulate inside setting up a concentration inside setting up a concentration gradient that provides the energy to gradient that provides the energy to make ATP and NADPHmake ATP and NADPH..

Stage 3: Storage of Stage 3: Storage of EnergyEnergy

CarbonCarbon atoms from atoms from carbon carbon dioxidedioxide in the atmosphere are used in the atmosphere are used to make organic compounds in to make organic compounds in which chemical energy is which chemical energy is storedstored..


The transfer of carbon dioxide to The transfer of carbon dioxide to organic compounds is called organic compounds is called carbon carbon dioxide fixation.dioxide fixation.


Calvin Cycle- Calvin Cycle- a series of enzyme-a series of enzyme-assisted chemical reactions that assisted chemical reactions that produces a 3-carbon sugar.produces a 3-carbon sugar.

Factors that affect Factors that affect Photosynthesis include:Photosynthesis include:

1). Amount of light1). Amount of light

2). Amount of CO2). Amount of CO22

3). Temperature 3). Temperature

(certain temps (certain temps

can inactivatecan inactivate

certain enzymes)certain enzymes)

Cellular Respiration Cellular Respiration

CC66HH1212OO66 + 6O + 6O22 6CO 6CO22 + 6H + 6H22O + energy O + energy (ATP)(ATP)

enzymes

Equation

Most Foods we eat contain Most Foods we eat contain USEABLE ENERGY.USEABLE ENERGY. But But before you can use that before you can use that energy it is transferred to energy it is transferred to ATPATP



Cellular Respiration- Cellular Respiration- the process the process cells use to make energy; uses cells use to make energy; uses glucose and oxygen to make glucose and oxygen to make ATPs which are necessary to run ATPs which are necessary to run our cells and bodyour cells and body


OXYGENOXYGEN in the air you in the air you breathe make the production breathe make the production of ATP more of ATP more EFFECIENTEFFECIENT, , although some is made although some is made without oxygen. without oxygen.

Metabolic process that Metabolic process that REQUIRES OXYGENREQUIRES OXYGEN is called is called AEROBICAEROBIC. .

A metabolic process that A metabolic process that DOES NOT DOES NOT REQUIRE OXYGENREQUIRE OXYGEN is called is called ANAEROBICANAEROBIC meaning “without air”. meaning “without air”.


Stage One- Stage One- Breakdown Breakdown of of GlucoseGlucose

Primary fuel for cellular Primary fuel for cellular respiration is respiration is GLUCOSEGLUCOSE

GLUCOSEGLUCOSE is broken down in the is broken down in the CYTOPLASMCYTOPLASM during the process during the process called called GLYCOLYSIS.GLYCOLYSIS.

Stage Two: Stage Two: Production Production of of ATPATP

When When OXYGENOXYGEN is present, is present, PYRUVATE PYRUVATE produced during glycolysis enters a produced during glycolysis enters a MITOCHONDRION MITOCHONDRION and is converted to and is converted to a two-carbon compound. a two-carbon compound.

This reaction produces This reaction produces 11 carbon dioxide, carbon dioxide, 11 NADH molecule, and NADH molecule, and 11 two-carbon two-carbon acetyl that is attached to a molecule acetyl that is attached to a molecule called a called a COENZYME A (CoA)COENZYME A (CoA) forming a forming a compound called compound called ACETYL CoA.ACETYL CoA.

Electron Transport ChainElectron Transport Chain

• Acetyl-CoA enters a series of enzyme assisted reactions called the KREB’S CYCLE

In In AEROBIC RESPIRATIONAEROBIC RESPIRATION electrons donated by electrons donated by NADHNADH and and FADHFADH2 2 pass through an pass through an ELECTRON TRANSPORT ELECTRON TRANSPORT CHAINCHAIN located in the located in the INNER INNER membranes of membranes of MITOCHONDRIA.MITOCHONDRIA.

Electron Transport ChainElectron Transport Chain

STEPS FOR ELECTRON STEPS FOR ELECTRON TRANSPORT CHAINTRANSPORT CHAIN


1.The electron transport chain pumps HYDROGEN ions out of the inner compartment.

Label on picture.

2. At the end of the chain 2. At the end of the chain ELECTRONSELECTRONS and and HYDROGENHYDROGEN ions ions combine with combine with OXYGEN OXYGEN forming forming WATER.WATER.



Label on picture.

3. ATP3. ATP is produced as is produced as hydrogen ions diffuse into hydrogen ions diffuse into the inner compartment the inner compartment through a through a CHANNEL CHANNEL protein. protein.



Label on picture.

Fermentation in the Fermentation in the Absence of OxygenAbsence of Oxygen

What happens when there is not What happens when there is not enough oxygen for aerobic respiration? enough oxygen for aerobic respiration?

Under Under ANAEROBIC ANAEROBIC conditions, conditions, electrons carried by NADH are electrons carried by NADH are transferred to transferred to PYRUVATE PYRUVATE produced produced during during GLYCOLYSIS.GLYCOLYSIS. This recycles This recycles NAD+NAD+ needed to continue making needed to continue making ATP.ATP.

The recycling of The recycling of NAD+NAD+ using an using an ORGANIC HYDROGEN ORGANIC HYDROGEN ACCEPTORACCEPTOR is called is called FERMENTAION.FERMENTAION.

Fermentation in the Fermentation in the Absence of OxygenAbsence of Oxygen

1). Lactic Acid Fermentation1). Lactic Acid Fermentation A three-carbon A three-carbon PYRUVATEPYRUVATE is is

converted to a three-carbon converted to a three-carbon LACTATE. LACTATE.

Lactate is the ion of an Lactate is the ion of an organic acid called organic acid called LACTIC LACTIC ACID.ACID.

Two Types of Two Types of FermentationFermentation

Examples of Lactic Acid Examples of Lactic Acid fermentationfermentation

Used in the production of Used in the production of YOGURTYOGURT and and CHEESECHEESE; also ; also during during VIGOROUS VIGOROUS exercise a exercise a build up of lactate causes muscle build up of lactate causes muscle SORENESSSORENESS. .

2). Alcoholic Fermentation2). Alcoholic Fermentation A three-carbon A three-carbon PYRUVATEPYRUVATE is is

broken down into broken down into ETHANOL ETHANOL (ethyl alcohol). (ethyl alcohol).

CARBON DIOXIDECARBON DIOXIDE is released in is released in the process. the process.

Two Important Types of Two Important Types of FermentationFermentation

Examples of alcoholic Examples of alcoholic fermentaion fermentaion

Used in the preparation of Used in the preparation of WINEWINE, , BEERBEER, rising of , rising of BREAD BREAD dough, dough, and and CARBONATION CARBONATION of alcoholic of alcoholic beverages. beverages.

Photosynthesis Cellular RespirationFood synthesized Food broken down

Energy from sun stored in glucose Energy of glucose released

Carbon dioxide taken in Carbon dioxide given off

Oxygen given off Oxygen taken in

Produces sugars from PGAL Produces CO2 and H2O

Requires light Does not require light

Occurs only in presence of chlorophyll

Occurs in all living cells

Table 9.1 Comparison of Photosynthesis and Cellular Respiration

Although both processes use electron carriers and form ATP, they accomplish quite different tasks as shown in the table.

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Photosynthesis & Cellular Respiration. Energy and Living Things Where does energy in food come from? Directly or indirectly, almost all energy comes