Cellular Respiration
Gazette
By Camille Dyhr & Josie Kelly
Letters to the Editor
Dear Editor,
I was trying to study for a
biology
1test, but I ended up becoming
extremely confused. The test is on
cellular respiration and I thought I
knew all about it, but now I’m not so
sure. I read about something called
“aerobic respiration” and
“anaerobic respiration”. I didn’t
know there were different kinds of
cellular respiration! Please help
before I fail my test!
Lost in Bio
ConfusedSo you thought there’s only one
type of cellular respiration? Think
again. There is 2 types of cellular
respiration: aerobic (requires
oxygen) and anaerobic (doesn’t
require oxygen). Each is used in
different situations, when the other
type of respiration cannot be used. In
aerobic respiration, there’s 3 steps.
First, glucose is broken down into
pyruvic acid in Glycolysis. Next,
pyruvic acid (changed t Acetyl CoA)
is used to make electrons in the
Krebs Cycle (Also known as the
Citric Acid Cycle). In the final step,
the Electron Transport chain, the
electrons are used to convert ADP
into ATP.
Much differently, in
anaerobic respiration, also called
fermentation, there are 2 different
types. Both start with Glycolysis, but
then the pyruvic acid creates ethyl
alcohol and carbon dioxide One type
is alcoholic fermentation (used in
making bread and beer) and the other
type is lactic acid fermentation
(glucose is converted into lactic
acid). Animals cannot perform
alcoholic fermentation, but certain
organisms can, such as yeast.
Fermentation only makes 2 ATP
altogether, so it’s not as effective as
aerobic respiration. Good luck on
your test and hopefully you won’t get
confused again!
Dear EditorThere seems to be some
confusion over how many ATP
molecules are produced for each step
in each kind of respiration. Many
numbers have been floating around,
and I was wondering if you could
clear that up for me.
Overwhelmed
OverwhelmedSorry for your confusion, I know
that ATP molecules can be
confusing. First, in aerobic
respiration, you have 3 steps. In the
1st one, Glycolysis, a net gain of 2
ATP molecules is produced. In the
Krebs Cycle, 2 more ATP are
produced. In the electron transport
chain, 34 ATP are made. So 1
glucose molecule can produce 36
ATP all together in Cellular
respiration. In anaerobic respiration,
only 2 ATP are produced.
Dear Editor,
Every morning I go out jogging
for 20 minutes or so. Recently, a
friend told me that my body uses
cellular respiration to create oxygen
when I run. How does that work?
Curious
CuriousGreat question. Your friend was
right, sort of. For shorter-distanced
running, your body uses the small
amount of stored ATP it already has
from glycolysis and cellular
respiration. When that runs out, your
body produces more ATP by lactic
acid fermentation. But that doesn’t
last forever.
During longer runs, the body
has to perform cellular respiration.
This makes ATP slower than
fermentation, therefore you have to
pace yourself when running. Since
respiration requires oxygen, you
breathe hard when running, trying to
inhale as much oxygen as possible at
a time.
Photosynthesis vs. Respiration:
Opposites!
Perhaps you think
photosynthesis and Cellular
Respiration aren’t at all related.
Well, actually they are the opposite.
While Photosynthesis takes in carbon
dioxide to produce oxygen (among
other things), respiration takes in
oxygen and gives off carbon dioxide
(among other things). To help
comprehend this, we’ve created a
table.
Photosy
nthesis
Respi-r
ation
Users
Plants
Animals
and
plants
Function
Uses
sunlight
to make
glucose
Eats
plants to
make
glucose
Takes
in
Carbon
Dioxide
Oxygen
Gives
off
oxygen
Carbon
dioxide
Co +
H 0+
Light
Glucose
+O
Glucose
+O 
Co +
water +
ATP
off
Equatio
n
QUICK GUIDE: All the Words
You NEED to Know
Okay, so when you talk
about cellular respiration, there’s a
lot of words that might seem new to
you. Here’s a few that are important
to understand:
 Cellular Respiration: The
process that releases energy by
breaking down food molecules in
the presence of oxygen.
 Glycolysis: The process in
which glucose is broken in half,
producing two molecules of
pyruvic acid, a 3-carbon
compound.
 Fermentation: A process that




releases energy from food
molecules in the absence of
oxygen.
Anaerobic: process that doesn’t
require oxygen.
Aerobic: A process that requires
oxygen.
Krebs Cycle: 2nd stage of
respiration where pyruvic acid is
broken down into Co2 in
energy-extracting reactions.
Electron transport Chain:
series of proteins where high
energy electrons from Krebs
cycle are used to convert ADP to
ATP
FUN CORNER!
Word Search
(Answer key on back)