Chapter 8 & 9

Photosynthesis and Cellular Respiration

http://images.google.com/imgres?imgurl=http://ebiomedia.com/prod/LC/images/CellEnergy_img_26.jpg&imgrefurl=http://ebiomedia.com/prod/LC/LCenergy.html&h=302&w=489&sz=20&hl=en&start=1&um=1&tbnid=95WqaKO_GfzkvM:&tbnh=80&tbnw=130&prev=/images%3Fq%3DCELLS%2BAND%2BENERGY%26svnum%3D10%26um%3D1%26hl%3Den%26sa%3DN

Chapter 8 & 9 Vocab

1. Aerobic

2. Anaerobic

3. Fermentation

4. Cellular respiration

5. Photosynthesis

6. Thylakoid

7. Electron transport

chain

8. NADP+

9. Chlorophyll

10. Glycolysis

11. Krebs cycle

12. Calvin cycle

13. ADP

14. Autotroph

15. Heterotroph

Formulas to Know!!

• Photosynthesis

CO2 + H2O light C6H12O6+ O2

Cellular Respiration

C6H12O6 + H2O + O2 CO2 + H2O + 36 ATP

Fermentation

C6H12O6 2 ATP + lactic acid

C6H12O6 2 ATP + ethyl alcohol + CO2

5-1 Objectives

• Compare the metabolism of autotrophs to that of heterotrophs.

• Describe the role of ATP in metabolism.

• Describe how energy is released from ATP.

Energy Flows Between Organisms in Living Systems

• 1. All energy comes from the sun.

• 2. Autotrophs- convert the sun’s energy into chemical energy.– Photosynthesis

– Chemotrophs-convert chemicals into energy

http://www.usoe.k12.ut.us/curr/science/sciber00/8th/energy/images/demo.jpg

• 3. Heterotrophs- get energy from food.

• 4. Cellular respiration- release of energy from food to make ATP.– Energy is temporarily

stored in ATP molecules

– ATP-energy currency for the cell.

– ATP is released to power chemcial reactions in cells.

http://www.smartdraw.com/examples/presentation-edu/images/foodchain.gif

ATP stores and releases energy.

• 1. Adenosine triphosphate- ATP

– 3 phosphates

– Very unstable- phosphates are negatively charged and repel one another.

– Removal of a phosphate group releases energy.

http://www.cat.cc.md.us/~gkaiser/biotutorials/energy/images/atp.gif

Adenosine Diphosphate-ADP• Removal of one phosphate from ATP

releases energy.

• This creates a new molecule-ADP

• A phosphate can be added to ADP to create a new molecule of ATP

www.smart-publications.com/.../Coenzyme_Q10.php

Like a rechargeable Battery

Review Questions

• 1. What is the difference between a eterotroph and an autotroph?

• 2. What is cellular respiration?

• 3. Where in the ATP molecule is the energy stored?

• 4. What is ADP?

• 5. What is ATP used for?

5-2 Objectives

• Summarize how energy is captured from sunlight in the first stage of photosynthesis.

• Relate the Calvin Cycle to carbon dioxide fixation.

• Identify three environmental factors that affect the rate of photosynthesis.

An overview of photosynthesis

http://www.ldeo.columbia.edu/edu/dees/ees/life/slides/light_dark_reactions.gif

Photosynthetic Organisms Use Energy from Sunlight.

• a. light reactions- require light.

• b. pigments-absorb light.– Includes Chlorophyll a

and b

http://micro.magnet.fsu.edu/cells/chloroplasts/images/chloroplastsfigure1.jpg

Production of Oxygen

• Electrons are excited by the light energy.

http://www.bios.niu.edu/sims/metabolism/c034f2c.gif

www.citruscollege.edu/apps/pub.asp?Q=810

Light Reactions• 2. Excited

electrons jump to an electron carrier- NADP+

• 3. Replacement electrons are provided by the splitting of water.

http://www.eeb.uconn.edu/Courses/Bio108/Roland's%20files/Roland07/img009.jpg

• NADP+ picks up 2 electrons and a Hydrogen ion and becomes NADPH.

How is water split?

2 H2O →4H+ + O2

4. 2 molecules of water make 4 hydrogen ions and 1 oxygen molecule.

Stage 2: Light Energy is Converted into Chemical Energy

• A. Excited electrons are used to produce new molecules that temporarily store chemical energy.

• B. Uses an electron transport chain

http://ghs.gresham.k12.or.us/science/ps/sci/ibbio/cellenergy/photopics/darklt.gif

Stage 3: Energy is stored in organic compounds

• a. called dark reactions- does not need light to occur.

• b.carbon dioxide fixation-used to make organic compounds.

http://www.windows.ucar.edu/earth/climate/images/carboncycle.jpg

The Calvin Cycle

• c. The Calvin Cycle– 1) produces 3 carbon

sugars that will be later used to make organic compounds (like glucose).

– 2) Energy is stored in these organic compounds.

http://www.britannica.com/nobel/art/ophosyn002a4.gif

Factors that affect photosynthesis• 1. Light

– Increased light, increases photosynthesis

• 2. Carbon Dioxide • 3. Temperature

– Enzymes that control photosynthesis work best at warm temperatures.

http://students.salisbury.edu/~ak09850/images/photosynthesisBASIC.jpg

How do plants prevent water loss?

http://www.marietta.edu/~spilatrs/biol103/photolab/stomata.gif

Stomata and Guard Cells

• Guard Cells- Open and close to prevent the loss of water and to allow gas exchange.

• Stomata- opening in middle of guard cell

• Plants open stomata just enough to keep gas exchange going but not so much that they lose water

http://www.cartage.org.lb/en/themes/sciences/botanicalsciences/PlantHormones/PlantHormones/stomates.gif

http://www.hobart.k12.in.us/jkousen/Biology/lfstoma.jpg

http://hcs.osu.edu/hcs300/gif/tsleaf.gif

Review Questions• 6. What does

chlorophyll do in photosynthesis?

• 7. Why is water split during the first stage of photosynthesis?

• 8. What gas is formed and the end of the first stage?

• 9.What is the difference between the light and the dark reactions?

• 10. What is the product of the Calvin Cycle?

• 11. What are the reactants in photosynthesis?

• 12. What are the products in photosynthesis?

5-3 Objectives

• Summarize how glucose is broken down in the first stage of cellular respiration.

• Describe how ATP is made during the second stage of cellular respiration.

• Evaluate the role of oxygen in aerobic respiration.

• Identify the role of fermentation in the second stage of cellular respiration.

• How do we get access the energy from the sun?

• We EAT

Food Burns! Page 254• THINK ABOUT IT Food burns! It’s

true,• of course, that many common foods

(think• of apples, bananas, and ground beef)

have too• much water in them to actually light

with a• match. However, foods with little water,

including sugar and cooking oil, will indeed burn. In fact, fl our, which contains

• both carbohydrates and protein, is so • flammable that it has caused several

explosions, including the one seen here at London’s City Flour

• Mills in 1872 (which is why you’re not supposed to store fl our above a

• stove). So, plenty of energy is available in food, but how does a living cell extract that energy without setting a fire or blowing things up?

Cellular Respiration: an Overview

Stage 1: Glycolysis

• Glucose is broken down – Glucose is converted

into pyruvate and ATP

– C6H12O6

pyruvate + 2 ATP

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/enyld1.gif

Stage 2: The Krebs Cycle

• 3.The energy from pyruvate is converted into:– a. NADH– b. FADH4. Acetyl-CoA- is recycled-

pyruvate is converted to this at the beginning of the cycle

5. Products are transferred to the electron transport chain

*all this takes place in the mitochondria!

http://www.bartek.ca/images/gifs/Krebs_cycle.gif

The Krebs Cycle

http://www.bbc.co.uk/scotland/education/bitesize/higher/img/biology/cell_biology/respiration/02krebscycle.gif

Stage 3: The Electron Transport Chain

• 1. Energy from electrons is used to pump hydrogen ions out of the inner membrane of mitochondria.

• 2. A concentration gradient is set up.

• 3. As hydrogen ions pass through carrier proteins, a phosphate is added to ADP

http://www.sp.uconn.edu/~terry/images/anim/ATPanim.gif

Electron Transport Chain

• 4. At the end of the chain, electrons are added to oxygen- the final electron acceptor!

• 5. Water is formed

http://fajerpc.magnet.fsu.edu/Education/2010/Lectures/19_Electron_Transport_files/image003.jpg

CR Rocks• On average 36 ATP

per molecule of glucose– 36% of the total energy

of glucose

– What happens to the rest of energy?

– Released as heat

– More efficient than a gas engine

• Lipids and proteins-can be broken down and used in Krebs cycle.

• So we can use other molecules besides glucose to make ATP

Sometimes, Oxygen is NOT the final electron acceptor.

• 1. nitrate- NO3

• 2. sulfate- SO4

• 3. Carbon dioxide-CO2

• 4. This is called anaeraobic respiration

• Clostridium (gangrene, food poisoning, tetanus)

• Porphyromonas (pneumonia, periodontitis)

• Bifidobacterium (ear and abdominal infections)

ClostridiumBifidobacterium

Porphyromonas

Fermentation

• Follows glycolysis in the absence of oxygen

www.begod.org/begod.html

Lactic Acid Fermentation

• C6H12O6 2 ATP + lactic acid Oxygen debt- a person cannot

take in enough oxygen to continue cellular respiration.

Lactic acid-Can build up in muscle cells and cause soreness.

http://sps.k12.ar.us/massengale/images/modlacticacidferm.jpg

Alcoholic Fermentation

• Overview:

C6H12O6 2 ATP + ethyl alcohol+ CO2

Yeasts and bacteria- Use fermentation and can be used to make bread, beer and wine.

http://www.sirinet.net/~jgjohnso/modalcoholicferm.jpg

Glycolysis vs. Fermentation: The Fate of Pyruvate

http://fig.cox.miami.edu/~cmallery/150/makeatp/pyraerobic.jpg

Review Questions• 13. What are the

products of glycolysis?

• 14. What molecule is recycled during the Krebs cycle?

• 15. What is the final electron acceptor in the electron transport chain?

• 16. In which phase of aerobic respiration is water formed?

• 17. How much ATP is made during glycolysis, Krebs cycle, and electron transport chain?

• 18. What organisms do fermentation?

• 19. Fermentation is identical to what process in aerobic respiration?