The Working Cell: Energy From The Working Cell: Energy From FoodFood

Chapter 7Chapter 7

Obtaining FoodObtaining Food

All organisms need food for energy.All organisms need food for energy.

AutotrophAutotroph- Makes its own food - Makes its own food ((photosynthesisphotosynthesis); ); producersproducers– Plants, algaePlants, algae

HeterotrophHeterotroph- Cannot make own food; - Cannot make own food; consumersconsumers– AnimalsAnimals– Must eat producers or other consumersMust eat producers or other consumers

How do heterotrophs get energy How do heterotrophs get energy from food?from food?

Through Through Cellular RespirationCellular Respiration– Makes energy for the cell by breaking Makes energy for the cell by breaking

down glucosedown glucose– Uses oxygen to do this (why we need to Uses oxygen to do this (why we need to

breathe!) breathe!) – Energy is in the form of Energy is in the form of ATPATP

Food Stores EnergyFood Stores EnergyEnergyEnergy =The ability =The ability to perform work.to perform work.

2 forms:2 forms:– Kinetic Energy-Kinetic Energy- energy energy

of motionof motionThermal energy-Thermal energy- random molecular random molecular motion (heat)motion (heat)

– Potential Energy-Potential Energy- energy that is storedenergy that is stored

Chemical Energy-Chemical Energy- ready ready to do work; due to to do work; due to arrangement of atomsarrangement of atoms

Calories: Units of EnergyCalories: Units of Energy

CalorieCalorie- amount of energy required - amount of energy required to raise the temperature of 1 gram of to raise the temperature of 1 gram of water by 1 degree Celsius.water by 1 degree Celsius.– Tiny numberTiny number (too tiny to measure energy in (too tiny to measure energy in

food)food)

Energy in food is expressed in Energy in food is expressed in kilocalorieskilocalories– 1 kcal = 1000 cal1 kcal = 1000 cal

Measuring the Energy Content of a Measuring the Energy Content of a PeanutPeanut

Burning peanut converts its stored Burning peanut converts its stored chemical energy into thermal energy, chemical energy into thermal energy, releasing heatreleasing heat

Measure increase in water temp– Measure increase in water temp– calculate # of calories in a peanutcalculate # of calories in a peanut

1 peanut has 5000 calories (5 kcal) 1 peanut has 5000 calories (5 kcal)

____ °C x ____ mL = ____ cal/ 1000 = ____ °C x ____ mL = ____ cal/ 1000 = ___ kcal___ kcal

Do Cells “Burn” our food?Do Cells “Burn” our food?

No!!No!!

Use enzymes to break down organic Use enzymes to break down organic molecules through cellular molecules through cellular respiration, thus releasing energy.respiration, thus releasing energy.

Online ActivitiesOnline Activities

www.phsuccessnet.comwww.phsuccessnet.com

Complete online activities 7.1, 7.2, Complete online activities 7.1, 7.2, and ch. 7 prelab questions and ch. 7 prelab questions

Lab: Food as FuelLab: Food as FuelCalorimeter: Measures calorie content in Calorimeter: Measures calorie content in foodfood

We will be burning food to measure their We will be burning food to measure their calorie content. calorie content.

Remember: 1000 cal = 1 kcalRemember: 1000 cal = 1 kcal

Remember: Remember: CalorieCalorie- amount of energy - amount of energy required to raise the temperature of 1 required to raise the temperature of 1 gram of water by 1 degree Celsius.gram of water by 1 degree Celsius.

AnimationAnimation

Lab: Food as FuelLab: Food as Fuel

The longer something burns, the The longer something burns, the more energy (kcal) it has.more energy (kcal) it has.– Proteins/ carbs 4 kcal/gProteins/ carbs 4 kcal/g– Fats 9 kcal/g Fats 9 kcal/g

ATPATP

Adenosine Tri-PhosphateAdenosine Tri-Phosphate

Stores energyStores energy

Provides energy for chemical Provides energy for chemical reactions.reactions.

The ATP CycleThe ATP Cycle

ATP is continuously converted to ADP ATP is continuously converted to ADP as your cells do work.as your cells do work.

ATP is “recyclable” ATP is “recyclable”

Energy that makes this happen is Energy that makes this happen is from foodfrom food

Mighty MitochondriaMighty MitochondriaMitochondria Mitochondria makes energy!makes energy!

Site of cellular Site of cellular respiration in a cellrespiration in a cell

Cristae (folds) & Cristae (folds) & matrix (thick fluid)matrix (thick fluid)

Cellular RespirationCellular Respiration

Converts energy in food to energy in Converts energy in food to energy in ATPATP

glucose+ oxygen glucose+ oxygen carbon dioxide carbon dioxide + water + energy+ water + energy

CC66HH1212OO66 + 6O + 6O22 6CO 6CO2 2 + 6H+ 6H22O + O + 38ATP38ATP

Try This…Try This…

The atoms in cellular respiration are The atoms in cellular respiration are merely rearranged by breaking the merely rearranged by breaking the bonds.bonds.

Using the molecular model kits, Using the molecular model kits, model the process of cellular model the process of cellular respiration. respiration.

CC66HH1212OO66 + 6O + 6O22 6CO 6CO22 + 6H + 6H22O + O + 38ATP38ATP

ReviewReview

6 H6 H22OO

Subscript: # of atoms

Coefficient: # of molecules

CC66HH1212OO6 6 + 6O + 6O22 6CO 6CO22 + 6H + 6H22O + 36ATPO + 36ATP

Lab ReviewLab Review

Lab- we burned food to release Lab- we burned food to release energy (different from our bodies… energy (different from our bodies… we use we use enzymesenzymes to do this) to do this)

The more fat, the longer it burned The more fat, the longer it burned (what is this telling us?)(what is this telling us?)

What is a calorie? A kilocalorie? What is a calorie? A kilocalorie?

CR ReviewCR Review

Cellular Respiration is making energy Cellular Respiration is making energy (in the form of ATP) from glucose.(in the form of ATP) from glucose.

CR takes place in the mitochondria of CR takes place in the mitochondria of cells (“mighty mitochondria”)cells (“mighty mitochondria”)

Activity with ball-and-stick models Activity with ball-and-stick models shows that atoms are neither created shows that atoms are neither created nor destroyed in CR, just rearranged nor destroyed in CR, just rearranged to release energy.to release energy.

glucose+ oxygen glucose+ oxygen carbon dioxide carbon dioxide + water + energy+ water + energy

CC66HH1212OO66 + 6O + 6O22 6CO 6CO2 2 + 6H+ 6H22O + O + 38ATP38ATP

Three Stages of CRThree Stages of CR

1) Glycolysis (in CYTOPLASM of cell)1) Glycolysis (in CYTOPLASM of cell)

2) Krebs Cycle (in MITOCHONDRIA 2) Krebs Cycle (in MITOCHONDRIA CRISTAE)CRISTAE)

3) Electron Transport Chain (in 3) Electron Transport Chain (in MITOCHONDRIA MATRIX)MITOCHONDRIA MATRIX)

GlycolysisGlycolysis

Glucose Pyruvic Acid + 2 ATP Glucose Pyruvic Acid + 2 ATP

2 ATP used to make this happen 2 ATP used to make this happen

Oxygen is NOT needed (anaerobic) Oxygen is NOT needed (anaerobic)

Krebs CycleKrebs Cycle

Cristae of mitochondriaCristae of mitochondria

Pyruvic Acid carbonic acid + Pyruvic Acid carbonic acid + CO2 + 2 ATPCO2 + 2 ATP

Needs Oxygen!Needs Oxygen!

Electron Transport ChainElectron Transport Chain

Matrix of mitochondriaMatrix of mitochondria

Most of the energy is made here!Most of the energy is made here!

Carbonic acid + O2 H2O + 34 Carbonic acid + O2 H2O + 34 ATPATP

Needs Oxygen!Needs Oxygen!

Is it possible to make ATP without Is it possible to make ATP without oxygen??oxygen??

Fermentation in Human Muscle Fermentation in Human Muscle CellsCells

Long Distance Running– muscles Long Distance Running– muscles regenerate ATP through CRregenerate ATP through CR

Sprint– lungs/blood can’t supply Sprint– lungs/blood can’t supply oxygen fast enough to make enough oxygen fast enough to make enough ATP!ATP!

How does this happen?? How does this happen?? FERMENTATION- makes ATP without FERMENTATION- makes ATP without using oxygenusing oxygen

Lactic Acid FermentationLactic Acid Fermentation

Occurs in muscle cellsOccurs in muscle cells

But only small amts of ATP madeBut only small amts of ATP made

Glycolysis still occursGlycolysis still occurs– Glucose Pyruvic Acid + 2 ATPGlucose Pyruvic Acid + 2 ATP

Pyruvic acid CO2 + Lactic acidPyruvic acid CO2 + Lactic acid

Lactic Acid is what makes your Lactic Acid is what makes your muscles sore after a lot of hard muscles sore after a lot of hard exercise!exercise!

TrainingTraining

Improves ATP productionImproves ATP production

Weight lifting & sprinting = increase Weight lifting & sprinting = increase glycogen & lactic acid toleranceglycogen & lactic acid tolerance

Long-distance running= increase Long-distance running= increase mitochondria & oxygen delivery to mitochondria & oxygen delivery to cellscells

Alcoholic FermentationAlcoholic Fermentation

No oxygen present in yeast cell No oxygen present in yeast cell environmentenvironment

Ethyl alcohol produced instead of Ethyl alcohol produced instead of lactic acidlactic acid

Pyruvic acid CO2 + ethyl alcoholPyruvic acid CO2 + ethyl alcohol

Cellular Respiration LabCellular Respiration Lab

Cell Respiration- converting the Cell Respiration- converting the chemical energy of organic chemical energy of organic molecules into a form immediately molecules into a form immediately usable by organismsusable by organisms

What is this chemical energy called?What is this chemical energy called?

What is the usable form called?What is the usable form called?

Cellular Respiration LabCellular Respiration Lab

All organisms, including plants and All organisms, including plants and animals break down glucose for animals break down glucose for energy using oxygen. energy using oxygen.

Peas undergo CR during germination. Peas undergo CR during germination.

Germination of PeasGermination of Peas

What does germination mean?What does germination mean?

Cellular Respiration LabCellular Respiration Lab

Today, you will be using the COToday, you will be using the CO22 gas gas sensor to measure the rate of CR in sensor to measure the rate of CR in germinating and ungerminating germinating and ungerminating peas.peas.

Lab ProcedureLab Procedure

Do you expect the carbon dioxide Do you expect the carbon dioxide levels to increase or decrease?levels to increase or decrease?

Will the rates be the same in the Will the rates be the same in the germinating and ungerminating germinating and ungerminating peas?peas?

1 ATP1 ATP

Organisms that make their own food Organisms that make their own food are called ______________.are called ______________.

1 ATP1 ATP

Organisms that cannot make their Organisms that cannot make their own food and must obtain energy own food and must obtain energy from the foods they eat are called from the foods they eat are called _______________._______________.

2 ATPs2 ATPs

Cell respiration uses oxygen to Cell respiration uses oxygen to convert the chemical energy stored convert the chemical energy stored in organic molecules into _________.in organic molecules into _________.

3 ATPs3 ATPs

Energy is released from ATP when a Energy is released from ATP when a ____________ is released.____________ is released.

4 ATPs4 ATPs

What is the chemical equation for What is the chemical equation for cellular respiration?cellular respiration?

Hint:Hint:Glucose + oxygen = carbon dioxide + Glucose + oxygen = carbon dioxide +

water + energywater + energy

2 ATPs2 ATPs

How many total ATPs are made as a How many total ATPs are made as a result of cellular respiration?result of cellular respiration?

3 ATPs3 ATPs

What is the What is the net gainnet gain of ATPs as a of ATPs as a result of glycolysis?result of glycolysis?

3 ATPs3 ATPs

List the steps of cellular respiration in List the steps of cellular respiration in order.order.

3 ATP3 ATP

The Krebs cycle starts with The Krebs cycle starts with _____________ and yields carbon _____________ and yields carbon dioxide.dioxide.

2 ATP2 ATP

What process is used to make bread What process is used to make bread rise?rise?

1 ATP1 ATP

Is cellular respiration aerobic or Is cellular respiration aerobic or anaerobic?anaerobic?

1 ATP1 ATP

Is fermentation aerobic or anaerobic?Is fermentation aerobic or anaerobic?

2 ATP2 ATP

Where does lactic acid fermentation Where does lactic acid fermentation take place?take place?

2 ATPs2 ATPs

Where in the cell does glycolysis take Where in the cell does glycolysis take place?place?

2 ATPs2 ATPs

Where in the cell does the Krebs Where in the cell does the Krebs cycle take place?cycle take place?

2 ATPs2 ATPs

Where in the cell does the electron Where in the cell does the electron transport chain take place?transport chain take place?

3 ATPs3 ATPs

Without oxygen, a cell can make only Without oxygen, a cell can make only _______ ATPs from each glucose _______ ATPs from each glucose molecule.molecule.

3 ATPs3 ATPs

Glysolysis converts glucose into 2 Glysolysis converts glucose into 2 molecules of _____________.molecules of _____________.

4 ATPs4 ATPs

What is the difference between What is the difference between kinetic and potential energy?kinetic and potential energy?

4 ATPs4 ATPs

What is the definition of a calorie?What is the definition of a calorie?

1 ATP1 ATP

# 4 is the __________ of the # 4 is the __________ of the mitochondria.mitochondria.

3 ATPs3 ATPs

The device used to measure the The device used to measure the amount of calories in a piece of amount of calories in a piece of popcorn is called a __________.popcorn is called a __________.

2 ATPs2 ATPs

There are __________ calories in a There are __________ calories in a kilocalorie.kilocalorie.

2 ATPs2 ATPs

What is the function of ATP?What is the function of ATP?

4 ATPs4 ATPs

What does ATP stand for?What does ATP stand for?

3 ATPs3 ATPs

Most energy made from cellular Most energy made from cellular respiration comes from this stage.respiration comes from this stage.

2 ATPs2 ATPs

What makes your muscles sore after What makes your muscles sore after hard exercise?hard exercise?