CELLULAR RESPIRATION Pages 228 - 237. CELLULAR RESPIRATION 1.All organisms respire! 2.Cellular...

CELLULAR RESPIRATIONPages 228 - 237

CELLULAR RESPIRATION

1. All organisms respire!2. Cellular respiration is like the

reverse reaction of photosynthesis – Products of photosynthesis become the

reactants of cellular respiration– Respiration breaks down glucose (Catabolic

Rxn.)3. ATP energy is released

– ATP is used for cellular processes like movement of materials, cellular reproduction, protein synthesis, etc.

Overview of Respiration

Glucose

CELLULAR RESPIRATION

4. What Organelle is involved in cellular respiration?

MITOCHONDRIAMITOCHONDRIA

Overview of Respiration

CELLULAR RESPIRATION

Two Types of Cellular Respiration:

1. Aerobic (Requires Oxygen)2. Anaerobic (No oxygen

required)

Overview of Respiration

CELLULAR RESPIRATION

C6H12O6 + 6O2 6CO2 + 6H2O + Energy

Ok! Lets look at our Reactants!1) Glucose2) Oxygen

Wait! You just told me there is a process that does not reqire oxygen??

Overview of Respiration(Aerobic)

• This is where it gets confusing……

• For the purposes of this class, we are going to focus on regular cellular respiration which is aerobic (requires oxygen).

• However, keep in mind that some simple organisms can only do anaerobic (no oxygen required) cellular respiration.

Where do the reactants come from?

Glucose - made during Photosynthesis.

Oxygen - is in the air.

CELLULAR RESPIRATION

• The formula for aerobic cellular respiration is

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP)

• The “word” equation for this is:

Cellular RespirationAEROBIC

RESPIRATION

• Aerobic cellular respiration has 3 stages.

1.Glycolysis

2.Krebs cycle

3.Electron Transport Chain, or ETC

Cellular RespirationAEROBIC RESPIRATION

Glucose is Broken Down•Inputs:

– 1 Glucose– 2 ATP

• Outputs:– 2 Pyruvate – 2 NADH– 2 ATP Net (4 ATP made but 2 used = 2 left)

Occurs in the CYTOPLASM

Step 1: GLYCOLYSIS

Step 1: GLYCOLYSIS

Per 1 molecule of glucose and 2 molecules of ATP, how many….

Net # of ATP made?NADPH made?Pyruvate made?

Where does pyruvate come from?

Where does glycolysis take place?

AEROBIC RESPIRATION

• The step in which pyruvate is broken down • Inputs:

– 2 Pyruvate

• Outputs:– 2 ATP– 8 NADH– 2 FADH2

– 6 CO2

• Occurs in the mitochondria

Step 2: KREB’S CYCLE

AEROBIC RESPIRATION

Step 2: KREB’S CYCLE

Step 3: ELECTRON TRANSPORT

CHAIN• In this step, the breakdown of Glucose is completed.

• Inputs:– 8 NADH– 2 FADH2

– 6 O2

• Outputs:– 32 ATP– 6 H2O

• Occurs in the mitochondria

Step 3: ELECTRON TRANSPORT

CHAIN

• The mitochondrial electron transport chain is similar to that used in chloroplasts for photosynthesis. NADH and FADH2 molecules formed during Glycolysis and Krebs Cycle carry their electrons to the electron transport chain. The electron transport chain creates a proton gradient that ultimately leads to the production of a large amount of ATP.

Animation

WOW! MY BRAIN HURTS!

Maybe a Video Will Help

http://www.youtube.com/watch?v=00jbG_cfGuQ

Summary of Aerobic Respiration

• Glycolysis breaks down glucose into pyruvate. 2 ATP Made

• Pyruvate is further broken down in the Kreb’s Cycle. 2 ATP Made

• The electron transport chain finishes breaking down glucose and makes 32 ATP

• CO2 and Water are wastes (or byproducts).

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

36 ATP MADE TOTAL

Cellular Respiration

2 36

Where does Glycolysis take place?

Glycolysis

What does Glycolysis require?

What is step 2 of cellular respiration?

Glycolysis

Where does the Krebs Cycle take place?

Glycolysis

What does the Krebs Cycle Make?

What does the ETC Use?

What does the ETC Make?

ANAEROBIC RESPIRATIONCellular respiration when oxygen is NOT present is called

ANAEROBIC- NO OXYGEN!!

• Some cells can function for a little while without oxygen.

• Other Cells may go their entire life without oxygen.

But they still need ENERGY!!

CELLULAR RESPIRATION

•Can release energy when oxygen is not present but...

•It’s far less efficient.•Begins with glycolysis followed by fermentation.

ANAEROBIC RESPIRATION

Same as Before: Glucose is Broken Down•Inputs:

– Glucose– 2 ATP

• Outputs:– 2 Pyruvate – 2 NADH– 4 ATP

Occurs in the CYTOPLASM

Step 1: GLYCOLYSIS

Special Note: Glycolysis can produce

thousands of ATP molecules in milliseconds.But quickly fills all available NAD+ (electron carriers) with electrons and the process stops, so it’s only good for short-term energy.

ANAEROBIC RESPIRATION

1.Type of anaerobic respiration that releases energy without oxygen

2.If oxygen is not present, the next step is eithera. Lactic acid fermentationb. Alcoholic fermentation

Step 2: FERMENTATION

ANAEROBIC RESPIRATION

Lactic Acid Fermentation– Converts pyruvic acid into

lactic acid and CO2

– Responsible for food production using microbes (Swiss cheese)

– Causes muscle fatigue/burning

Step 2: FERMENTATION

ANAEROBIC RESPIRATION

Alcoholic Fermentation– Converts pyruvic acid into

alcohol and CO2

– Responsible for food production using microbes (sourdough bread)

Step 2: FERMENTATION

02+ C6H12O6 6CO2 + 6H2O + ATP + alcohol

or lactic acid

Summary Of Fermentation

Glycolysis Fermentation

Advantage of Aerobic Respiration

Yields 66% more energy

36 net ATPThat’s nearly 20 times more ATP than

glycolysis alone.

Energy Yield without oxygen

Glycolysis 4 ATP (gross)Fermentation+ 2 ATP 6 ATP

But 2 ATP go back into glycolysis as the energy to start the reaction, so there is only 4 net ATP from anaerobic respiration!!! (32 less than aerobic)

A. to make ATP

B. to process H2O

C. to store glucose

D. to deliver oxygen

What is the overall purpose of cellular respiration?

Cellular Energy

8.3 Formative Questions

Chapter 8

Which represents the general sequence of cellular respiration?

Cellular Energy

A. TCA cycle chemiosmosis glycolysis

B. glycolysis Krebs cycle electron transport

fermentation

D. aerobic pathway anaerobic pathway

8.3 Formative Questions

C. electron absorption catalysisphosphorylation

Chapter 8

A. glycolysis

B. Krebs cycle

C. electron transport

Which stage of cellular respiration is the anaerobic process?

Cellular Energy

8.3 Formative Questions

Chapter 8

A. CoA

B. CO2

C. FADH2

D. NADH

Which molecule generated by the Krebs cycle is a waste product?

Cellular Energy

8.3 Formative Questions

Chapter 8

What prevents pyruvate from entering the Krebs cycle and instead results in this pathway?

Cellular Energy

A. a buildup of CO2

B. a lack of oxygen

Standardized Test Practice

Chapter 8

C. an excess of glucose

D. an increaseddemand for ATP