Cellular Respiration

Cellular Cellular RespirationRespirationHonors Agriculture BiologyHonors Agriculture Biology

Why are photosynthesis and Why are photosynthesis and respiration important in respiration important in agriculture?agriculture?

BiomassBiomass is all plant and animal matter on the is all plant and animal matter on the Earth's surface. Harvesting biomass such as Earth's surface. Harvesting biomass such as crops, trees or dung and using it to generate crops, trees or dung and using it to generate energy such as heat, electricity or motion, isenergy such as heat, electricity or motion, is bioenergy.bioenergy.

Farmers try to maintain a 40:1 ratio of Farmers try to maintain a 40:1 ratio of photosynthesis to respiration, thus increasing photosynthesis to respiration, thus increasing the amount of biomass stored by the plants.the amount of biomass stored by the plants.

More Biomass= More EnergyMore Biomass= More Energy

Why is Respiration Why is Respiration Important?Important?

Plants use oxygen in the air (or water) to Plants use oxygen in the air (or water) to turn their food (glucose) into energy. turn their food (glucose) into energy. This process of using oxygen to release This process of using oxygen to release energy from food is called energy from food is called

cellular respirationcellular respiration

Interest GrabberInterest Grabber What kind of organisms undergo cellular What kind of organisms undergo cellular

respiration?respiration?

All organisms including photosynthetic All organisms including photosynthetic organisms, undergo cellular respiration as organisms, undergo cellular respiration as long as oxygen is presentlong as oxygen is present

Interest Grabber Interest Grabber

How are the products of How are the products of photosynthesis and respiration photosynthesis and respiration related?related?

The products of photosynthesis are the The products of photosynthesis are the starting materials for respirationstarting materials for respiration

Cellular RespirationCellular Respiration

CC66HH1212OO66 + 6O + 6O22 6CO6CO22 + 6H + 6H22O + Energy (ATP)O + Energy (ATP)

Cellular RespirationCellular Respiration

Photosynthesis vs. Photosynthesis vs. RespirationRespiration

PhotosynthesisPhotosynthesis Food synthesized (made)Food synthesized (made) Energy from sun stored in Energy from sun stored in

glucoseglucose CO2 taken inCO2 taken in Oxygen given offOxygen given off Produces sugarsProduces sugars Requires lightRequires light Occurs only in the presence Occurs only in the presence

of chlorophyllof chlorophyll

RespirationRespiration Food broken downFood broken down Energy in glucose Energy in glucose

releasedreleased CO2 given offCO2 given off Oxygen taken inOxygen taken in Produces CO2 and H2OProduces CO2 and H2O Does not require lightDoes not require light Occurs in all living cellsOccurs in all living cells

Chemical Pathways Chemical Pathways Cells don’t “burn” glucoseCells don’t “burn” glucose They gradually release the energy from They gradually release the energy from

glucose and other food compoundsglucose and other food compounds The process begins with a pathway The process begins with a pathway

called GLYCOLYSIS.called GLYCOLYSIS. Glycolysis releases only a small amount of Glycolysis releases only a small amount of

energy (net yield of 2 ATP)energy (net yield of 2 ATP)

Glycolysis Glycolysis Process in which one molecule of Process in which one molecule of

glucose is broken in halfglucose is broken in half Occurs in the cytoplasm of the cellOccurs in the cytoplasm of the cell This is an anaerobic processThis is an anaerobic process Produces two molecules of pyruvic acidProduces two molecules of pyruvic acid

A 3 carbon compoundA 3 carbon compound

Glycolysis Glycolysis

At the pathway’s beginning, 2 molecules At the pathway’s beginning, 2 molecules of ATP are used upof ATP are used up These 2 molecules should be looked at as These 2 molecules should be looked at as

an “investment” an “investment” Gives the cell 2 net ATP moleculesGives the cell 2 net ATP molecules

Glycolysis Glycolysis This process seems like it doesn’t create This process seems like it doesn’t create

very much energy very much energy But…the cells are able to finish the But…the cells are able to finish the

process so fast, that they can create process so fast, that they can create thousands of ATP molecules in just a few thousands of ATP molecules in just a few millisecondsmilliseconds

Interest Grabber Interest Grabber Some of the steps in cellular respiration Some of the steps in cellular respiration

take place in the membrane inside the take place in the membrane inside the cell structure called the mitochondrion, cell structure called the mitochondrion, which has a folded inner membrane. which has a folded inner membrane. What purpose do these folds serve?What purpose do these folds serve?

To find out the answer to this question, To find out the answer to this question, perform this activity.perform this activity.

Interest Grabber Interest Grabber Obtain two sheets of paper and a metric ruler. What is Obtain two sheets of paper and a metric ruler. What is

the surface area of the paper? the surface area of the paper? Roll one sheet of paper into a tube lengthwise. What is Roll one sheet of paper into a tube lengthwise. What is

the surface area of the rolled paper?the surface area of the rolled paper? Fold the second sheet of paper into a fan. Then, roll Fold the second sheet of paper into a fan. Then, roll

the first sheet of paper around the folded paper so it is the first sheet of paper around the folded paper so it is inside the rolled paper. What has happened to the inside the rolled paper. What has happened to the surface area of the inside of the rolled paper?surface area of the inside of the rolled paper?

What would be the value of increasing the surface area What would be the value of increasing the surface area of the membrane inside a mitochondrion?of the membrane inside a mitochondrion?

The Krebs CycleThe Krebs Cycle In the presence of oxygen, pyruvic acid In the presence of oxygen, pyruvic acid

produced in glycolysis passes to the second produced in glycolysis passes to the second stage of cellular respirationstage of cellular respiration

The Kreb’s Cycle (also known as the Citric Acid The Kreb’s Cycle (also known as the Citric Acid Cycle) occurs in the mitochondria of the cellCycle) occurs in the mitochondria of the cell

Named after Hans KrebsNamed after Hans Krebs 1937; he discovered the details of what is now 1937; he discovered the details of what is now

known as the Krebs Cycleknown as the Krebs Cycle

Krebs Cycle Krebs Cycle During the Krebs cycle the following During the Krebs cycle the following

occursoccurs Pyruvic acid is broken down into carbon Pyruvic acid is broken down into carbon

dioxide in a series of energy-extracting dioxide in a series of energy-extracting reactionsreactions

NADH, FADH2, CO2 and ATPNADH, FADH2, CO2 and ATP A total of 2 ATP are created from this stageA total of 2 ATP are created from this stage

Krebs Cycle Krebs Cycle Every time you exhale, carbon dioxide is Every time you exhale, carbon dioxide is

releasedreleased This carbon dioxide is produced by the This carbon dioxide is produced by the

Krebs CycleKrebs Cycle The ATP produced is used for cellular The ATP produced is used for cellular

activitiesactivities

Electron Transport Electron Transport Electrons passed around during the Electrons passed around during the

Krebs Cycle to the electron transport Krebs Cycle to the electron transport chainchain

The electron transport chain uses the The electron transport chain uses the high-energy electrons from the Krebs high-energy electrons from the Krebs Cycle to convert ADP into ATPCycle to convert ADP into ATP

A total of 32 ATP are created in the A total of 32 ATP are created in the mitochondria during this stage of resp.mitochondria during this stage of resp.

Electron Transport ChainElectron Transport Chain

Activity (see handout)Activity (see handout) ProcedureProcedure

Predict (in your lab book) how exercise will affect your body’s Predict (in your lab book) how exercise will affect your body’s production of Carbon Dioxide (COproduction of Carbon Dioxide (CO22))

In one test tube put 10 ml of water and 4 drops of In one test tube put 10 ml of water and 4 drops of bromothymol blue solutionbromothymol blue solution Bromothymol turns yellow or green in the presence of COBromothymol turns yellow or green in the presence of CO22

One person will take a straw and place it in the test tube. One person will take a straw and place it in the test tube. Another group member will act as a timer during this step. Another group member will act as a timer during this step.

SLOWLY blow air in the straw while being timed. SLOWLY blow air in the straw while being timed. When the solution changes color, your partner should say When the solution changes color, your partner should say

“stop,” and then record how long the color change took.“stop,” and then record how long the color change took.

ActivityActivity Procedure-ContinuedProcedure-Continued

Rinse out the test tube.Rinse out the test tube. Refill with 10 ml of water and 4 drops of Refill with 10 ml of water and 4 drops of

bromothymol blue.bromothymol blue. The same person as before needs to jog in The same person as before needs to jog in

place for 1 minutes.place for 1 minutes. Repeat the procedure of blowing in the straw Repeat the procedure of blowing in the straw

slowly and timing for color change.slowly and timing for color change. Record how long the color change took.Record how long the color change took.

ActivityActivity Answer the following questions in your Answer the following questions in your

lab notebook with the data you recorded.lab notebook with the data you recorded. How did exercise affect the time for the How did exercise affect the time for the

solution to change color?solution to change color? What process in your body produces carbon What process in your body produces carbon

dioxide? How does exercise affect this dioxide? How does exercise affect this process?process?

Fermentation Fermentation If oxygen is not present, glycolysis is If oxygen is not present, glycolysis is

followed by a different pathwayfollowed by a different pathway The combined process of this pathway The combined process of this pathway

and glycolysis is called FERMENTATIONand glycolysis is called FERMENTATION Fermentation releases energy from food Fermentation releases energy from food

molecules in the absence of oxygenmolecules in the absence of oxygen

Fermentation Fermentation There are two types of fermentationThere are two types of fermentation

Alcoholic FermentationAlcoholic Fermentation Lactic Acid FermentationLactic Acid Fermentation

Alcoholic Fermentation Alcoholic Fermentation Produces carbon dioxide and ethyl Produces carbon dioxide and ethyl

alcohol as wastesalcohol as wastes This is what is produced when yeast is This is what is produced when yeast is

used to make breadused to make bread When the yeast in the dough runs out of air, When the yeast in the dough runs out of air,

it begins to ferment and produces bubbles of it begins to ferment and produces bubbles of carbon dioxide to rise the doughcarbon dioxide to rise the dough

Pyruvic Acid + NADH = Alcohol + CO2 + NAD+

Lactic Acid Fermentation Lactic Acid Fermentation Produces lactic acid and NADProduces lactic acid and NAD++ as wastes as wastes Produced in your muscles during rapid Produced in your muscles during rapid

exercise when the body cannot supply exercise when the body cannot supply enough oxygen to the tissueenough oxygen to the tissue

Pyruvic Acid + NADH = Lactic acid and NAD+

Quick Energy vs. Quick Energy vs. Long Term Energy Long Term Energy

The body provides enough ATP to last The body provides enough ATP to last about 90 seconds-Quick Energyabout 90 seconds-Quick Energy Enough time for a runner to finish a 200-300 Enough time for a runner to finish a 200-300

meter dashmeter dash Fermentation produces lactic acid as a by Fermentation produces lactic acid as a by

productproduct Getting rid of lactic acid requires oxygenGetting rid of lactic acid requires oxygen

Thus a runner breathes heavily at the end of the Thus a runner breathes heavily at the end of the race to rid the muscles of lactic acid that built uprace to rid the muscles of lactic acid that built up

Quick Energy vs. Quick Energy vs. Long Term Energy Long Term Energy

How about when you need energy for a How about when you need energy for a long time?long time? The body relies on cellular respiration to The body relies on cellular respiration to

release energy more slowlyrelease energy more slowly This is why athletes must pace themselves This is why athletes must pace themselves

over a long race---why?over a long race---why? To allow oxygen to fuel the process of cellular To allow oxygen to fuel the process of cellular

respiration and make more ATP!!!respiration and make more ATP!!!