CHAPTER 7:
CELLULAR RESPIRATION
SEC.1:
ANAEROBIC RESPIRATION
SEC.2:
AEROBIC RESPIRATION
Objectives:
•Summarize how glucose is broken down in the first
stage of cellular respiration.
•Describe how ATP is made in the second stage of
cellular respiration.
•Identify the role of fermentation in the second
stage of cellular respiration.
•Evaluate the importance of oxygen in aerobic
respiration.
VOCABULARY
Cellular Respiration – the transfer of energy
from an organic compound into ATP
Fermentation – the breakdown of carbohydrates
by enzymes in the absence of oxygen
Aerobic- with oxygen
Anaerobic – without oxygen
CELLULAR RESPIRATION
Cellular Respiration is a metabolic process
like burning fuel
Releases much of the energy in food to
make ATP
This ATP provides cells with the energy they
need to carry out the activities of life.
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
CELLULAR RESPIRATION
Takes place in ALL living organisms
 Plants
 Animals
 Some bacteria
Where as photosynthesis takes place only in plants!!
WHERE DO CELLULAR
RESPIRATION OCCUR?
Anaerobic respiration occur in the cytosol
Aerobic respiration occur in the Mitochondria
MITOCHONDRIA
Where glucose is
broken down
releasing CO2 ,
water, and ATP
ATP
Most of the energy from cell
respiration is converted into
ATP
ATP is a substance that
powers most cell
activities.
Cellular Energy
The Stages of Cellular Respiration Cellular
respiration has two stages.
1- Glycolysis The first stage of cellular respiration
is called glycolysis.
2Aerobic
O2
Anaerobic
No O2
Cellular Respiration
Stage One: Breakdown of Glucose
•Glycolysis Glucose is
broken down to
pyruvate during
glycolysis, making
some ATP.
Let’s chant!
“Glycolysis breaks
down glucose!!!”
GLYCOLYSIS
•
•
•
•
2 ATP molecules are consumed
4 ATP molecules are produced
The net gain is 2 ATP molecules
2 NADH molecules are produced
12
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
Stage Two : in the “Absence of Oxygen”
Fermentation
•Fermentation When oxygen is not present (anaerobic),
fermentation follows glycolysis,
•Regenerating NAD+ needed for glycolysis to continue.
LACTIC ACID
ALCOHOLIC
oAnaerobic respiration happen in …………………..of Oxygen
oLactic acid fermentation ends with production of ……………….
oAlcoholic fermentation starts with ……………and ends with ………….
oPrecipitation of lactic acid in muscles cause……………
(pyruvic
acid- absence – muscle pain – lactic acid – Ethanol )
Stage Two: In Presence of Oxygen”
1-Krebs Cycle - series of
reactions that produce ATP
during aerobic respiration.
2-Electron Transport
Chain - large amounts of
ATP are made in an
electron transport chain.
1- KREPS CYCLE: (CITRIC ACID CYCLE)
Kreb’s cycle transfers energy to an
electron transport chain.
takes place in mitochondrial matrix
breaks down three-carbon molecules from
glycolysis
makes a small amount of ATP releases
carbon dioxide
transfers energy-carrying molecules
ELECTRON TRANSPORT CHAIN:
• The electron transport chain produces a
large amount of ATP.
–takes place in inner membrane
–energy transferred to electron transport
chain
–oxygen enters process
–ATP produced
• water released as a waste product
LETS OPEN OUR BOOKS
page 95
The efficiency of glycolysis
=2%
Page 102
The efficiency of cellular
respiration
=39%
Page 104
The summery of cellular respiration and chemical
equations
AEROBIC VS. ANAEROBIC RESPIRATION: A
COMPARISON
Advantages of Aerobic Respiration
1. Major advantage  more energy released
2. Enough energy to produce up to 38 ATP
Advantages of Anaerobic Respiration
1. Lets organisms live in places where there is little or no
oxygen
2. Quickly produces ATP
NOW LETS PLAY
According to the number on your flash card
answer and get your reward.
REVIEW
11
When oxygen is present most the ATP made in
cellular respiration is produced by:
A. aerobic respiration
B. Glycolysis
C. alcoholic fermentation
D. Lactic acid fermentation.
REVIEW
2
Which of the following is NOT responsible for
creation of ATP in cellular respiration?
A. Kreb’s cycle
B. glycolysis
C. Calvin Cycle
D. electron transport
REVIEW
3
When oxygen is absent, what type of process
will occur?
A. aerobic respiration
B. fermentation
C. electron transport
D. Kerb’s cycle
REVIEW
4
Which of the following is the correct equation for
cellular respiration?
A. C6H12O6 + O2 + CO2  H2O + ATP
B. C6H12O6 + O2  CO2 + H2O + ATP
C. CO2 + H2O + Sunlight  C6H12O6 + O2
D. CO2 + H2O + ATP  C6H12O6 + O2
REVIEW
5
Where does aerobic respiration take place in a
cell?
A. chloroplast
B. stomata
C. mitochondria
D. cytosol
REVIEW
6
Why is fermentation important to
cells?
A. used to make yeast
B. regenerates energy molecules
C. Produces a LOT of ATP
D. used to make yogurt and bread