Cellular Respiration
Learning Goals
1. Recognize that organisms, including plants, use cellular
respiration to release energy from food.
2. Know that cellular respiration produces 36 ATP molecules.
3. Learn the three main steps of cellular respiration.
4. Know the equation of cellular respiration and that it is the
opposite or reverse of photosynthesis.
5. Be able to identify the 2 types of fermentation and list their
products.
6. Know under what conditions fermentation happens
instead of cellular respiration.
Energy from Food
•
All organisms, plants and
animals, need energy
and they get that energy
from food.
•
Autotrophs make their
own food but they must
be able to convert that
food energy into energy
that their cells can use.
Cellular Respiration
•
This is the process that is
used to release the
energy from food (oxygen
is present).
•
The organelle where it
takes place is the
mitochondria
Oxygen
•
Aerobic is with oxygen.
You use a lot of oxygen
with aerobic exercise.
•
Anaerobic means without
oxygen
Cellular Respiration
32
Step 1: Glycolysis
•
The first step of cellular
respiration
•
It takes place in the
cytoplasm of the cell.
•
It does not need oxygen
•
It is very fast
•
Net gain of 2 ATP. 2 ATP to
start the chemical reaction
and 4 ATP released
Step 2: Krebs Cycle
•
Takes place in the
mitochondria
•
Series of reactions
•
Carbon Dioxide is
released as carbons of
glucose are broken apart
•
2 ATP is the gain and
molecules that are
needed for the next step
(NADH and FADH2)
Step 3: Electron Transport
Chain
•
Takes place in the
mitochondria, the
inner membrane
•
Oxygen is needed
and water is released
•
32 ATP is the gain
Summary: Cellular
Respiration
•
Process organisms (including plants) use to release
energy from their food
•
Produces about 36 ATP
•
Glucose and Oxygen is needed, water and carbon
dioxide is released
•
C6H12O6 + 6 O2 —> 6 H2O + 6 CO2
•
It has three main steps. Glycolysis, Krebs Cycle and
Electron Transport Chain
ATP & ADP
•
ATP molecule has 3
phosphate groups
•
ADP molecule has 2
phosphate groups
•
When the end
phosphate group is
broken off of ATP is
releases energy for the
cell (and becomes
ADP)
•
Cellular respiration
turns 36 ADPs back
into ATPs
Anaerobic?
•
When we exercise very hard our body can not
get oxygen to our cells fast enough.
•
How do cells and some organisms get the
energy they need without oxygen?
Fermentation
•
Fermentation releases energy from food and
produces ATP in anaerobic conditions(without
oxygen).
•
There are two types: alcohol fermentation and
lactic acid fermentation.
•
Both start with glycolysis
Lactic Acid Fermentation
•
This is what your body does. So
when you sprint very fast your
body can’t get enough oxygen
to your muscle cells and they
use Lactic Acid Fermentation to
make ATP
•
Glycolysis and Lactic Acid
fermentation gives 2 lactic acid
molecules and 2 ATPs from 1
glucose molecule
Alcohol Fermentation
•
This is what yeast does. Following
glycolysis carbon dioxide and
alcohol are produced by alcohol
fermentation.
•
2 ATP, 2CO2 and 2 ethyl alcohol
molecules are produced.
•
The CO2 produced makes bread
rise, the alcohol is what is found
in beer and wine.
Review Questions
1. Do plants use cellular respiration?
2. How many ATP molecules does cellular respiration
produce?
3. How is ATP different then ADP?
4. What are the three main steps of cellular respiration?
5. What is the equation of cellular respiration?
6. What are the 2 types of fermentation, and list their
products.
7. When does fermentation take place?
The End