9.3 Getting Energy to Make ATP

1
9.3 Getting Energy to Make ATP

• How do consumers (animals) get energy from the
  producers (plants)?
• Cellular respiration - break down glucose
  molecules to produce your own ATP

2
Photosynthesis
Cellular Respiration
3
Cellular Respiration

• 3 Stages of Cellular respiration
• Glycolysis
• Citric Acid Cycle
• Electron Transport Chain

4
Glycolysis

• Rxns that break down glucose (6C) into 2 pyruvic
  acids (3C)
• Occurs in cytoplasm
• Anaerobic
• Not very effective, only 2 NET ATP produced (2
  ATP in, 4 ATP out)

5
Citric Acid Cycle

• Just before CAC, Pyruvic acid goes into
  mitochondria and is turned into Acetyl-CoA

• Then we start CAC, Aka Krebs Cycle- makes energy
  carriers for ETC (NADH and FADH2)
• First product is Citric Acid
• Aerobic
• Occurs in mitochondria
• Makes more 2 ATP and 2 CO2 (breath out)

6
Progression of C through first 2 steps of
Cellular Respiration
Energy carrirs like NADPH and ATP
7
Electron Transport Chain (ETC)

• Uses E carriers from CAC drop e- to make ATP

• e- passed down several proteins, losing E along
  the way
• E used to pump in H

Occurs in the membrane of the mitochondria. Aerob
ic Makes 34 ATP
8
ETC

• The last e- acceptor is O, uses those plus H to
  make WATER.
• If No O is present the staircase backs up NO
  E
• H ions want out (w/gradient) only way is through
  the ATPsynthase
• Adds P on to ADP ATP

9
What if there is no oxygen?

• Fermentation
• Glycolysis still happens, but next step is
  differnent
• Essentially makes enough E to run glycolysis
• Lactic Acid Fermentation
• Used by animal cells
• Produces lactic acid and 2 ATP
• Alcoholic Fermentation
• Used by yeast and some bacteria
• Produces CO2 and ethyl alcohol

10
Glycolysis
CO2 and H20 total 36 ATP
2 ATP
2 ATP
11
Compare and Contrast

• Photosynthesis
• Food/Glucose made
• CO2 taken in
• O2 given off
• H20 broken down
• Requires light
• Occurs in cells with chlorophyll

• Cellular Respiration