Interest Grabber

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Interest Grabber

Rolling and Folding

Some of the steps in cellular respiration take place in the membrane inside the cell structure called the mitochondrion, which has a folded inner membrane. What purpose do these folds serve?To find out the answer to this question, perform this activity.

Section 9-2

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Interest Grabber continued

1. Obtain two sheets of paper and a metric ruler. What is the surface area of the paper? 2. Roll one sheet of paper into a tube lengthwise. What is the surface area of the rolled

paper?3. Fold the second sheet of paper into a fan. Then, roll the first

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

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

Section 9-2

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1.Obtain two sheets of paper and a metric ruler. What is the surface area of the paper?

The area will vary depending on the size of paper used. A sheet of notebook paper has an area of approximately 600 cm3.

Section 9-2

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

The surface area is the same as the original sheet of paper.

Section 9-2

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3.Fold the second sheet of paper into a fan. Then, roll the firstsheet of paper around the folded paper so it is inside the rolled paper.What has happened to the surface area of the inside of the rolled paper? The surface area has increased (surface area of rolled paper + surface area of folded paper).

Section 9-2

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4. What would be the value of increasing the surface area of the membrane inside a mitochondrion? Increasing the surface area increases the amount of space where chemical reactions can take place.

Section 9-2

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Section Outline

9–2 The Krebs Cycle and Electron TransportA. The Krebs CycleB. Electron TransportC. The TotalsD. Energy and Exercise

1. Quick Energy2. Long-Term Energy

E. Comparing Photosynthesis and Cellular Respiration

Section 9-2

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Glucose

Glycolysis Krebs cycle

Electrontransport

Fermentation (without oxygen)

Alcohol or lactic acid

Chemical Pathways

Section 9-1

The “fork in the road” happens following glycolysis. It just depends if oxygen is absent or present in deciding the path it takes next.

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Citric Acid Production

Figure 9–6 The Krebs CycleSection 9-2

Mitochondrion

We will focus on the citric acid production first.

Video 1

• Chapter 09A.mpg video

Video 1

Aerobic Respiration

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FlowchartSection 9-2

Glucose(C6H1206)

+Oxygen

(02)

Glycolysis KrebsCycle

ElectronTransport

Chain

Carbon Dioxide

(CO2)+

Water(H2O)

Cellular Respiration

We will next focus on the Krebs Cycle. This is the path that is taken when oxygen is present.

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Citric Acid Production

Figure 9–6 The Krebs CycleSection 9-2

Mitochondrion

Video 3

• Chapter 09C.mpg video

Video 3

Krebs Cycle, Part 1

•The end product of glycolysis was pyruvic acid (also known as pyruvate). The pyruvic acid enters the mitochondrion.•The pyruvic acid & coenzyme A combine to form acetyl-CoA.•1 carbon atom from pyruvic acid becomes part of carbon dioxide and is released into the air.•1 CO2 and 1 NADH are produced.

Krebs Cycle Animation-(select #1)

Acetyl-CoA Formation:

http://www.science.smith.edu/departments/Biology/Bio231/krebs.html


Citric Acid Formation:

•Pyruvic acid combines with oxaloacetic acid (oxaloacetate) to form citric acid, a 6-carbon molecule.



Electron Carriers are Reduced:

•In each turn of the Krebs cycle, the cell quickly converts a molecule GTP (guanosine triphosphate) into ADP producing ATP.

•A pair of high-energy electrons is accepted by electron carriers, changing NAD+ to NADH and FAD into FADH2.


Video 4

• Chapter 09D.mpg video

Video 4

Krebs Cycle, Part 2

Krebs Cycle (continued)

•1 pyruvic acid generates 3 CO2

4 NADH 1 FADH2

1 ATP

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FlowchartSection 9-2

Glucose(C6H1206)

+Oxygen

(02)

Glycolysis KrebsCycle

ElectronTransport

Chain

Carbon Dioxide

(CO2)+

Water(H2O)

Cellular Respiration

We will next focus on the Electron Transport Chain.

Video 5

• Chapter 09E.mpg

Video 5

Electron Transport Chain, Part 1

Video 6

• Chapter 09F.mpg video

Video 6

Electron Transport Chain, Part 2

Electron Transport Chain Animation-(select start, continue, and #1)

Electron Transport Chain:

•High-energy electrons from NADH are passed along the electron transport chain.

•Every time 2 high-energy electrons transport down the electron transport chain, their energy is used to transport hydrogen ions (H+) across the membrane.

http://www.science.smith.edu/departments/Biology/Bio231/etc.html



•High-energy electrons from FADH2 are passed along the electron transport chain.

•Every time 2 high-energy electrons transport down the electron transport chain, their energy is used to transport hydrogen ions (H+) across the membrane.

http://www.science.smith.edu/departments/Biology/Bio231/etc.html


Electron Transport Chain:•The high concentration of hydrogen ions in the intermembrane space represents potential energy that is harnessed to make ATP.

•As H+ escape through protein channels, ATP synthase spin.

•Each time is rotates, ATP synthase grabs a low-energy ADP and attaches a phosphate forming ATP.


At the end of the electron transport chain, is an enzyme that combines the electrons with the hydrogen ions and oxygen to form water.Oxygen serves as the final electron acceptor of the electron transport chain.

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Figure 9–7 Electron Transport ChainSection 9-2

Electron TransportHydrogen Ion Movement

ATP Production

ATP synthase

Channel

Inner Membrane

Matrix

Intermembrane Space

Mitochondrion

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GlucoseGlycolysis

Cytoplasm

Pyruvic acid

Electrons carried in NADH

Krebs Cycle

Electrons carried in

NADH and FADH2 Electron

Transport Chain

Mitochondrion

Figure 9–2 Cellular Respiration: An Overview

Mitochondrion

Section 9-1

• KREBS CYCLE• (also called the ___________ CYCLE)

• Happens in ___________

• NADPH donates _______________• ATP donates _________________• CO2 donates

_________________________ • to make __________•

mitochondria

Citric acid

ENERGY

STROMA

Hydrogen

Carbon & oxygen

GLUCOSE

SOUTH DAKOTA CORE SCIENCE STANDARDS

• 9-12.L.1.1. Students are able to relate cellular functions and processes to specialized structures within cells.

• Photosynthesis and respiration• ATP-ADP energy cycle

Role of enzymesMitochondriaChloroplasts

LIFE SCIENCE:Indicator 1: Understand the fundamental structures, functions, classifications, and mechanisms found in living things

Core High School Life SciencePerformance Descriptors

High school students performing at the ADVANCED level:

analyze chemical reaction and chemical processes involved in the Calvin Cycle and Krebs Cycle;

predict the function of a given structure;

High school students performing at the PROFICIENT level:

describe and give examples of chemical reactions required to sustain life (…role of enzymes)describe and give examples of chemical reactions required to sustain life (hydrolysis, dehydration synthesis, photosynthesis, cellular respiration, ADP/ATP, role of enzymes);describe the relationship between structure and function

High school students performing at the BASIC level

name chemical reactions required to sustain life (… role of enzymes)name chemical reactions required to sustain life (hydrolysis, dehydration synthesis, photosynthesis, cellular respiration, ADP/ATP, role of enzymes);recognize that different structures perform different functions;

SOUTH DAKOTA ADVANCED SCIENCE STANDARDS

• 9-12.L.1.1A. Students are able to explain the physical and chemical processes of photosynthesis and cell respiration and their importance to plant and animal life. (SYNTHESIS)

• Examples: Krebs Cycle

LIFE SCIENCE:Indicator 1: Understand the fundamental structures, functions, classifications, and mechanisms found in living things.

Internet

• Links from the authors on Creatine• Share kimchi lab data• Interactive test

• For links on cellular respiration, go to www.SciLinks.org and enter the Web Code as follows: cbn-3091.

• For links on the Krebs cycle, go to www.SciLinks.org and enter the Web Code as follows: cbn-3092.

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