KREBS CYCLE & ELECTRON TRANSPORT Chapter

REMEMBER: The “fork in the road” happens following glycolysis. The presence or absence of _______________ decides which path it takes next.

See video 9A AEROBIC RESPIRATIONvideo 9A

Flowchart Section 9-2 Glucose (C 6 H ) + Oxygen (0 2 ) Glycolysis Cellular Respiration We will next focus on the Krebs Cycle. This is the path that is taken when oxygen is present.

Image from BIOLOGY Miller and Levine; Prentice Hall Publishing _______________ follows glycolysis if oxygen is present

See video 9C See video 9Dvideo 9C video 9D KREBS CYCLEKREBS cont’d

REMEMBER: Glycolysis happens in the ________________ outside the mitochondria. Krebs cycle happens in _____________ inside the mitochondria

_______________ (also called pyruvate) enters the _________________ Pyruvic acid joins with _______________ to form ________________ Diagram by Riedell

WHERE DO THESE GO? Carbon dioxide is released into the ________________ High energy electron carriers move into the ____________________ (We will come back to this later)

Krebs Cycle AnimationKrebs Cycle Animation-(select #2) Citric Acid Formation: 2 carbon ACETYL-COA combines with a 4 carbon molecule to form a 6-carbon molecule called _______________.

WHERE DO THESE GO? Coenzyme A goes back to pick up another ________________ Citric acid completes the ____________

KREBS CYCLE PRODUCES ____ KREBS CYCLE Krebs Cycle AnimationKrebs Cycle Animation-(select #3)

WHERE DOES IT GO? 6 carbons in original glucose are lost as ________________ to atmosphere →

WHERE DO THESE GO? ATP can be used directly to supply __________ for the cell. High energy electron carriers move into the ____________________

Flowchart Section 9-2 Glucose (C 6 H ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Cellular Respiration We will next focus on the the Electron Transport Chain

WHERE DOES IT HAPPEN? Enzymes for ELECTRON TRANSPORT CHAIN are located in the ___________________________

See video 9E See video 9Fvideo 9E video 9F ELECTRON TRANSPORT ET cont’d

ELECTRON TRANSPORT CHAIN Image from: BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006 INTERMEMBRANE SPACE MATRIX CRISTAE

Electron Transport Chain AnimationElectron Transport Chain Animation- (select start, continue, and #1) Electron Transport Chain: High-energy _____________ from __________ and __________ are passed along the electron transport chain. Energy from passing electrons is used to transport _____________________ across the membrane.

The pumping of H + ions into the _______________________ represents potential energy that is harnessed to make ATP. As H + ions escape through ion channels back into the matrix, ________________ spins and adds a phosphate to ADP to form _______ Electron Transport Chain AnimationElectron Transport Chain Animation- (select start, continue, and #3) Electron Transport Chain:

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

High-energy electrons from ________ come in at beginning but electrons from _________ come in farther down the chain. Electron Transport Chain AnimationElectron Transport Chain Animation-(#1 and #2)

SO: NADH → _____ FADH 2 → _____

Glucose Glycolysis Cytoplasm Pyruvic acid Electrons carried in NADH Krebs Cycle Electrons carried in NADH and FADH 2 Electron Transport Chain Mitochondrion Figure 9–2 Cellular Respiration: An Overview WHATS THE BIG PICTURE?

CELLULAR RESPIRATION includes: ______________________ _______________________

GLYCOLYSIS Happens in ______________ Breaks down ____________ into ________________ Produces _______ __________

KREBS CYCLE happens in ________________ Breaks down _________________ Produces: ____ ____

ELECTRON TRANSPORT Enzymes found in _____________ Uses high energy electrons and H + ions donated by _______ and _______ Makes ___________ ________ acts a final electron acceptor to produce ________

Image from BIOLOGY Miller and Levine; Prentice Hall Publishing

CELLULAR RESPIRATION (aerobic/ with oxygen): 1 glucose → _______________ FERMENTATION (anaerobic/ without oxygen): 1 glucose → ________________

CARBOHYDRATES SUPPLY ENERGY Images from: Cells burn GLUCOSE for their energy needs Remember !

EXERCISE and ENERGY (Short term energy) Cells normally contain _________ amounts of ATP produced by _______________ & __________________________ (only enough for a few seconds of activity) Once this ATP is used up_____________ fermentation can provide enough ATP to last about ___________________.

EXERCISE and ENERGY (Short term energy) Once race is over, _______________ must be broken down using oxygen. Well __________ athletes burn lactic acid more efficiently. Image from:

EXERCISE and ENERGY (LONGER term energy) For exercise longer than 90 seconds _____________________ is the only way to make enough ATP. Cellular respiration releases energy _____________ than fermentation. Well conditioned athletes must pace themselves during a long race.

Animal cells store GLUCOSE as _____________ to use later. Image from: REMEMBER What happens in a long race when the body’s glucose all is used up?

EXERCISE and ENERGY (LONGER term energy) ________________ store glucose as ________________ which can be broken down into glucose to supply energy for_______________ of activity.

EXERCISE and ENERGY (LONGER term energy) After glycogen stores are used up the body begins to break down ________ That’s why aerobic exercise must continue for longer than 20 minutes if you want to lose weight! Image from:

ALL CELLS NEED ENERGY All __________________ (including plant and animal cells) have _______________ for cellular respiration All __________________ (bacteria) have their electron transport enzymes attached to their _____________________ Remember: No membrane bound organelles!