4.5 Cellular Respiration in Detail
Period 3: Take a textbook
and turn to page 115.
Period 4: Take out your book
and turn to page 69
4.5 Cellular Respiration in Detail
How are combustion and cellular respiration alike? How are
they different?
• Both are chemical reactions that use oxygen to release
energy; both produce heat.
• Cellular respiration releases energy slowly, with many
reactions, while combustion releases energy as heat and
light all at once
4.5 Cellular Respiration in Detail
KEY CONCEPT
Cellular respiration is an aerobic process with two
main stages.
4.5 Cellular Respiration in Detail
Glycolysis is needed for cellular respiration.
• The products of glycolysis enter cellular respiration when
oxygen is available.
– two ATP molecules are used to split glucose
– four ATP molecules (2 net) are produced
– two molecules of NADH produced
– two molecules of pyruvate produced
4.5 Cellular Respiration in Detail
The Krebs cycle (citric acid cycle) is the first main part of
cellular respiration.
• Pyruvate is broken down
before the Krebs cycle.
– **carbon dioxide
released
– NADH produced
– coenzyme A (CoA)
bonds to two-carbon
molecule
4.5 Cellular Respiration in Detail
• The Krebs cycle produces energy-carrying molecules.
4.5 Cellular Respiration in Detail
• The Krebs cycle produces energy-carrying molecules.
– NADH and FADH2 are made
– intermediate molecule with
CoA enters Krebs cycle
– citric acid
(six-carbon molecule)
is formed
– citric acid is broken down,
carbon dioxide is released,
and NADH is made
– five-carbon molecule is broken down, carbon dioxide is
released, NADH and ATP are made
– four-carbon molecule is rearranged
4.5 Cellular Respiration in Detail
The electron transport chain is the second main part of
cellular respiration.
• The electron transport chain uses NADH and FADH2 to
make ATP.
– #1: high-energy electrons removed from NADH and
FADH2 enter electron transport chain
– #2 energy from electrons in the electron transport chain
is used to pump hydrogen ions (H+) across the inner
mitochondrial membrane
– #3. hydrogen ions (H+) flow through a channel in the
membrane (ATP synthase), and ATP molecules are
produced
– #4: Oxygen picks up electrons that went through the
electron transport chain and hydrogen ions (H+)
4.5 Cellular Respiration in Detail
The electron transport chain is the second main part of
cellular respiration.
• The electron transport chain uses NADH and FADH2 to
make ATP.
• The breakdown of one glucose molecule produces up to
38 molecules of ATP.
– ATP synthase
produces ATP
– oxygen picks up
electrons and
hydrogen ions
– water is
released as a
waste product
4.5 Cellular Respiration in Detail
Does cellular respiration takes place only in animal cells?
Cellular respiration takes place in almost all organisms!
The cells of all eukaryotes have mitochondria.
Cellular respiration takes place in many prokaryotic
organisms as well, although they do not have mitochondria.
The enzymes and transport proteins are found free in the
cytoplasm and attached to the cell membrane.
4.5 Cellular Respiration in Detail
Period 3:
Complete the chapter review on page
125, #1-20, Odd numbered questions
only!
This will count as a quiz grade.
4.5 Cellular Respiration in Detail
Period 4:
Complete # 1-4 on page 72, “The big picture”
4.5 Cellular Respiration in Detail
Period 4:
Complete the Chapter 4 review,
THIS WILL COUNT AS A QUIZ
GRADE