Bi 102 (Summer 2006)  Harvesting Energy: Glycolysis and Cellular Respiration          Dr. Dutton

 

Chapter 8

 

I. How is Glucose metabolized?

Our bodies metabolize a variety of organic molecules

 

 

We’ll focus on _________________________ because:

1. All cells use glucose at least sometimes

2. Glucose metabolism is less complex

3. Other molecules may use the glucose metabolism pathway

Figure E8-2

 

The reaction:

 

C6H12O6  +  6O2 -->   6CO2  +  6H2O  + Chemical & Heat Energy

 

Is essentially symmetrical with Photosynthesis reaction:

 

       6CO2  +  6H2O  + Light  Energy  -->   C6H12O6  +  6O2

 

Is the conversion of Light Energy to Chemical Energy completely efficient?

 

The reaction:

C6H12O6 +  6O2 -->   6CO2  +  6H2O  + Chemical & Heat Energy

 

 

II. How is some energy gained during glycolysis?

 

 

_________________________ = “ to break apart a sweet”

Used by every living creature on the planet

Occurs in Cytoplasm

Two Steps:

 

A)

 

            Requires a small bit of Energy:

 

B)

 

            (Glycolysis produces a         small amount of Energy)

 

See Handout

 

Glycolysis = “ to break apart a sweet”

Used by every living creature on the planet

Occurs in Cytoplasm

Two Steps:

 

1) _________________________  _________________________

 

 

2) _________________________  _________________________

What happens next??

Depends on whether there are Aerobic or Anaerobic conditions

 

2 ATP and 2 NADH--> is that it?

What do cells do with pyruvate and NADH?         

 

 

1) Anaerobic Conditionsΰ _________________________

•         Microorganisms thrive without oxygen

•         Deep in soil sediments and oceans

•         Our muscles sometimes also go “anaerobic”

 

 

2) Aerobic Conditionsΰ _______________________  _______________________

•         Use Pyruvate and NADH to generate lots more ATP

 

III. Cellular Respiration

            Produces  more energy from pyruvate

 

•         Under aerobic conditions only

•         Series of enzyme catalyzed reactions

•         Occur in mitochondria

Figure 8.4

 

1) Each pyruvate transported into matrix

2) Split into CO2 and Acetyl

•         Acetyl+ coenzyme A= acetyl CoA

3) Enters Krebs cycle

•         Produces (per original pyruvate):

•         2 CO2

•         1 ATP

•         3 NADH  &  1 FADH2 -ΰ Electron Carriers

4) “energized” electron carriers go   to Electron Transport System

•         in inner membrane

 

5) Use _______________________  to make ATP

•         Energy of electrons is used to create H+ gradient

•         same process as in photosynthesis

6) ATP transported out to cytoplasm

How exactly did the chemiosmosis work?

Figure 8.6

H+ ions pass through channel in ATP synthesizing enzyme

Text Figure P 142

 

How much ATP does glucose breakdown produce?
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Table 8.1 – Know this!

 

See Handouts