Download PP Chapter 9 - Maria Regina High School

Cellular Respiration
Chapter 9
As you already know…
• Respiration is the process by which energy is
produced from sugar
• Respiration takes place inside a cell’s
Mitochondria
• There are two types of respiration:
• Aerobic respiration: Requires oxygen (Like aerobic
activity)
• Anaerobic respiration: Does NOT require oxygen
Stuff you don’t know…
• A calorie is the amount of energy needed to
raise 1 gram of water 1 degree Celsius
• The Calorie (Capital “C”)
found on food labels, is
really a Kilocalorie, or,
1,000 calories 
• When you eat food, you don’t actually burn
glucose inside your body (as in “burning
calories”) instead, you release small amounts
of energy at a time from glucose or other food
sources.
Overall Equation for Respiration
• Respiration is the exact opposite of photosynthesis
• Instead of using sun as energy, you create energy in the form
of ATP
C6H12O6 + 6O2  6CO2 + 6H2O + 36 ATP
1 sugar +
6 Oxygen  6 Carbon Dioxide + 6 Water + 36 ATP
•In order to create energy, a
series of steps must take
place
•Step 1:
•Glycolysis
•Step 2a (No oxygen):
•Fermentation
•Step 2b (Oxygen present):
•Kreb’s cycle
STEP 1: GLYCOLYSIS
• Glycolysis is the process by
which one sugar (glucose) is
broken in half and energy (ATP)
is released.
• 1st: 2 ATP molecules are used
to break apart the glucose
• 2nd: The process of breaking
apart the glucose produces 4
ATP molecules + 2 pyruvic
acids + 2 NADH
• Glycolysis produces a net gain of 2
ATP molecules
• NADH are electron transporters,
unlike ATP, they very temporarily
hold the energy
• The equation for Glycolysis is:
• 1 glucose + 2 ATP  2 pyruvic acids + 4
ATP + 2 NADH
STEP 2a: Fermentation
PROKARYOTES
EUKARYOTES
• If there is NO OXYGEN in the cell, fermentation takes
place (ANAEROBIC RESPIRATION)
• Fermentation recycles NADH back to NAD+ so that
GLYCOLYSIS may continue
• Prokaryotic cells use Alcohol Fermentation
• 2 Pyruvic acids + 2NADH  Alcohol + 2CO2 + NAD+
• Eukaryotic cells (US and MULTICELL ORGANISMS) use
Lactic Acid Fermentation
• 2 Pyruvic acids + 2NADH  2 Lactic Acids + 2 NAD+
• Without fermentation, glycolysis may only happen for a
few minutes! Otherwise, the NAD+ gets used up
STEP 2b: Kreb’s Cycle
• If there IS OXYGEN present (AEROBIC
RESPIRATION), the 2 pyruvic acids from
glycolysis are broken down into smaller pieces
(using the oxygen) creating a large quantity of
ATP
•
2 Pyruvic Acids + 6O2  6H2O + 6CO2 + 34 ATP
• The cycle is named the Kreb’s cycle after Hans
Kreb, the scientist who discovered it
• THE TOTAL ATP PRODUCED FROM RESPIRATION
= 2 ATP (glycolysis) + 34 ATP (Kreb’s cycle) = 36
ATP
The Equations
• Total Respiration:
1 glucose + 6O2  6CO2 + 6H2O + 36 ATP
• Glycolysis:
1 glucose + 2 ATP  2 pyruvic acids + 4 ATP + 2 NADH
• Alcohol Fermentation:
2 Pyruvic acids + 2NADH  Alcohol + 2CO2 + NAD+
• Lactic Acid Fermentation:
2 Pyruvic acids + 2NADH  2 Lactic Acids + 2 NAD+
• Kreb’s Cycle:
2 Pyruvic Acids + 6O2  6H2O + 6CO2 + 34 ATP
• TOTAL ATP = 36 ATP