Cellular Respiration
Zoom in:
muscle tissue
cell
mitochondria
cellular respiration occurs in the mitochondria
3 body systems are needed to make the mitochondria work;
digestion, circulation, and respiration
Why digestion?
through the digestive system the body acquires the food it
needs to fuel all cells
main food source needed are carbohydrates broken into
glucose molecules
the cell breaks the glucose into something smaller and sends
it off to the mitochondria
there the mitochondria uses these smaller pieces with
oxygen to make energy for you
Why circulation?
the heart and vessels are responsible to pump and transport
all nutrients to all parts of the body
through tiny vessels called capillaries are things like glucose,
oxygen and carbon dioxide able to enter or exit the tissue or
vessel
the only way to get glucose (from the intestine) and oxygen
(from the lung) to the cells of your toes are though blood
vessels
the blood vessels are essential in removing waste products
too, like carbon dioxide
Ka Hana ‘Imi Na‘auao – A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana
1
Why respiration?
the lungs are necessary to get oxygen into the body
in the lungs there are millions of little air sacs called alveoli
that are surrounded by capillaries
here the blood drops off carbon dioxide and picks up oxygen
this oxygen will be taken directly to the cells
when the oxygen gets to the cell, the mitochondria takes it
and begins the process of cellular respiration
What does the cell do with all this?
cell needs to get glucose and oxygen
molecules are taken in and a series of reactions begin
step 1: Glycolysis
the glucose molecule must break in half
new molecule called pyruvate
energy measured in ATP
2 ATP used at the beginning, but 4 gained at the end
profit of 2 ATP
2 ADP
2 ATP
2 ATP
2 ADP
Pyruvate
Glucose
Pyruvate
2 ADP
2 ATP
Ka Hana ‘Imi Na‘auao – A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana
2
step 2: Kreb’s Cycle
pyruvate can enter mitochondria only if oxygen is present
intermediary step before many ATP can be made
reaction called the Kreb’s Cycle, and produces important
electron carriers (2) called NADP(H)
Pyruvate + oxygen
NADPH
Kreb’s Cycle
NADPH
step 3: Electron Transport Chain
NADPH enters a chain reaction called the electron transport
chain
the “H” breaks off, and jumps around on certain proteins
in doing so each “H” produces 17 ATP
profit of 34 ATP (2 NADPH were made in the Kreb’s Cycle)
NADP H
H
17 ATP from 1 electron
Ka Hana ‘Imi Na‘auao – A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana
3
What if there’s no oxygen?
then everything ends at step 1
there is an alternate route called fermentation
the pyruvate molecule turns into lactic acid
lactic acid is responsible for making your muscles ache after
strenuous exercise
Glucose
Kreb’s Cycle
Electron Transport
Chain
36 ATP
Pyruvate
Fermentation
Occurs when there
isn’t oxygen to go to
the Kreb’s Cycle.
result of fermentation
is lactic acid which is
responsible for sore
muscles after
strenuous workouts
~ 6 ATP
Ka Hana ‘Imi Na‘auao – A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana
4
Teacher’s Notes: Cellular Respiration
Zoom in:
muscle tissue
cell
mitochondria
cellular respiration occurs in the mitochondria
3 body systems are needed to make the mitochondria work; digestion,
circulation, and respiration
Why digestion?
through the digestive system the body acquires the food it needs to fuel all
cells
main food source needed are carbohydrates broken into glucose molecules
the cell breaks the glucose into something smaller and sends it off to the
mitochondria
there the mitochondria uses these smaller pieces with oxygen to make energy
for you
Why circulation?
the heart and vessels are responsible to pump and transport all nutrients to all
parts of the body
through tiny vessels called capillaries are things like glucose, oxygen and
carbon dioxide able to enter or exit the tissue or vessel
the only way to get glucose (from the intestine) and oxygen (from the lung) to
the cells of your toes are though blood vessels
the blood vessels are essential in removing waste products too, like carbon
dioxide
Why respiration?
the lungs are necessary to get oxygen into the body
in the lungs there are millions of little air sacs called alveoli that are surrounded
by capillaries
here the blood drops off carbon dioxide and picks up oxygen
this oxygen will be taken directly to the cells
when the oxygen gets to the cell, the mitochondria takes it and begins the
process of cellular respiration
What does the cell do with all this?
cell needs to get glucose and oxygen
molecules are taken in and a series of reactions begin
Ka Hana ‘Imi Na‘auao – A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana
5
step 1: Glycolysis
the glucose molecule must break in half
new molecule called pyruvate
energy measured in ATP
2 ATP used at the beginning, but 4 gained at the end
profit of 2 ATP
step 2: Kreb’s Cycle
pyruvate can enter mitochondria only if oxygen is present
intermediary step before many ATP can be made
reaction called the Kreb’s Cycle, and produces important electron carriers (2)
called NADP(H)
step 3: Electron Transport Chain
NADPH enters a chain reaction called the electron transport chain
the “H” breaks off, and jumps around on certain proteins
in doing so each “H” produces 17 ATP
profit of 34 ATP (2 NADPH were made in the Kreb’s Cycle)
What if there’s no oxygen?
then everything ends at step 1
there is an alternate route called fermentation
the pyruvate molecule turns into lactic acid
lactic acid is responsible for making your muscles ache after strenuous
exercise
Ka Hana ‘Imi Na‘auao – A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana
6