Download 4.4 Overview of Cellular Respiration I. Respiration

4.4 Overview of Cellular Respiration
I. Respiration - converts sugar into ATP using oxygen
A. Cellular respiration is aerobic (requires oxygen)
B.  Takes place in mitochondria of ALL organisms at ALL
times
C.  Has 2 main stages:
1)  Kreb’s Cycle
mitochondrion
2)  Electron Transport Chain
animal cell
4.4 Overview of Cellular Respiration
D. Glycolysis must take place before respiration can occur.
1. anaerobic process (does not require oxygen)
2. takes place in cytoplasm
3. splits glucose into two three-carbon molecules
4. produces two ATP molecules
4.4 Overview of Cellular Respiration
E. Cellular respiration is like a mirror image of photosynthesis.
1.  Kreb s cycle transfers
energy to an electron
transport chain
a.  breaks down threecarbon molecules
from glycolysis
b.  makes a small amount
of ATP
c.  produces carbon
dioxide
d.  transfers energycarrying molecules
1
mitochondrion
matrix (area enclosed
by inner membrane)
ATP
and
6CO 2
energy
2
3
energy from
glycolysis
and
6O 2
inner membrane
ATP
and
6H 2 O
4
4.4 Overview of Cellular Respiration
2.  The electron transport chain produces a large amount of
ATP.
a.  oxygen enters process
b.  ATP produced
c.  water released as a waste product
1
mitochondrion
ATP
matrix (area enclosed and
by inner membrane) 6CO2
energy
3
energy from
glycolysis
and
6O2
2
inner membrane ATP
and
6H2 O
4
4.4 Overview of Cellular Respiration
F. The equation for the overall process is:
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
a. The reactants in photosynthesis are the same as the
products of cellular respiration.
4.5 Cellular Respiration in Detail
III. Glycolysis is needed for cellular respiration.
A. The products of glycolysis enter cellular respiration
when oxygen is available.
1. two ATP molecules are used to split glucose
2.  four ATP molecules are produced
3.  two molecules of NADH produced
4.  two molecules of pyruvate produced
4.5 Cellular Respiration in Detail
B. The Krebs cycle is the first main part of cellular
respiration.
1. Pyruvate is broken
down before the Krebs
cycle.
a. carbon dioxide
released
b. NADH produced
c. coenzyme A (CoA)
bonds to twocarbon molecule
4.5 Cellular Respiration in Detail
2. The Krebs cycle produces energy-carrying molecules.
a. NADH and FADH2 are made
b. intermediate molecule with
CoA enters Krebs cycle
c. citric acid
(six-carbon molecule)
is formed
d. citric acid is broken down,
carbon dioxide is released,
and NADH is made
e. five-carbon molecule is broken down, carbon
dioxide is released, NADH and ATP are made
f. four-carbon molecule is rearranged
4.5 Cellular Respiration in Detail
C. The electron transport chain is the second main part of
cellular respiration.
1. The electron transport chain uses NADH and FADH2 to
make ATP.
a. high-energy electrons enter electron transport chain
b. energy is used to transport hydrogen ions across the
inner membrane
c. hydrogen ions
flow through a
channel in the
membrane
4.5 Cellular Respiration in Detail
2. The breakdown of one glucose molecule produces up to
38 molecules of ATP.
a. ATP synthase produces ATP
b. oxygen picks up electrons and hydrogen ions
c. water is released as a waste product
4.6 Fermentation
IV. Fermentation allows glycolysis to continue if no oxygen
is present.
A. Fermentation is an anaerobic process
4.6 Fermentation
B. Lactic acid fermentation occurs in muscle cells.
1. glycolysis splits glucose into two pyruvate molecules
2. pyruvate and NADH enter fermentation
3. energy from NADH converts pyruvate into lactic acid
4. NADH is changed back into NAD+
4.6 Fermentation
C. Alcoholic fermentation is similar to lactic acid fermentation.
1.  glycolysis splits glucose and the products enter
fermentation
2.  energy from NADH is used to split pyruvate into an
alcohol and carbon dioxide
3. NADH is changed back into NAD+
4. NAD+ is recycled to glycolysis
4.6 Fermentation
D.  Fermentation is used in food production.
Ex) yogurt
Ex) cheese
Ex) bread