141 Respiration Problem Set

141 Respiration Problem Set - Bio141 Respiration Problem...

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Unformatted text preview: Bio141 Respiration Problem Set 
 Note: Supplemental Instruction Problem Sets provide you a means to test your ability to apply your knowledge to biological questions. It is highly suggested that you work on these on your own, but they do not have to be handed in and will not be graded. Your TAs will hold Supplemental Instruction sessions every week for discussion of the topics in these sets, but neither they nor your professor will provide you with the answer Instructions: Below are some screenshots from the movie that was shown in lecture. You can link to this video in Blackboard under the “Animations” tab: Mitochondria IN ACTION or go to http://multimedia.mcb.harvard.edu/.

Answer the questions that follow. You may need to reference your book, lecture notes, and other sources of information. 
 
 
 
 
 
 
 
 
 
 B
 A
 C
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1. Name
the
labeled
structures
above
(Note:
“C”
refers
to
involutions)
 2. What
processes
take
place
inside
of
A?
What
processes
take
place
outside
of
 A?
 
 
 
 (a) Where
do
these
take
place
in
a
prokaryotic
cell?
 
 
 
 Bio141 Respiration Problem Set 
 
 
 
 
 
 
 D
 
 
 
 
 
 
 
 
 
 
 
 
 E
 
 
 1.
Above
is
a
picture
above
of
a
crista

(D).

Why
does
the
mitochondria
have
so
 many
involutions
that
create
the
cristae?
 
 
 2.
During
active
respiration,
what
is
a
major
difference
in
the
environment
inside
D
 and
the
environment
outside
of
D?
 
 
 How
is
the
difference
in
the
environment
exploited
for
some
work?
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 F
 
 H
 G
 Bio141 Respiration Problem Set 
 
 1.

The
protein
complex
labeled
H
is
Complex
I
in
the
ETC,
labeled
E
in
the
previous
 picture.

F
comes
to
Complex
I
and
drops
off
something
and
is
thus
converted
to
G.


 What
is
F
and
what
is
“dropped
off”?
 
 
 
 2.

What
would
be
the
result
if
protein
H
had
a
defect
that
interfered
with
its
ability
 to
bind
F?

How
much
ATP
might
we
expect
a
cell
to
produce
(per
molecule
of
 glucose)
if
this
mutation
was
present?
Why?
 
 
 
 
 
 
 I
 
 1.
The
video
crosses
from
one
side
of
the
inner
membrane
to
the
other.

If
you
keep
 track
of
the
Complexes,
then
you
can
tell
where
you
are.

In
the
screen
shot
above
is
 Complex
IV,
also
called
cytochrome
C
oxidase.

Based
on
its
name,
predict
what
 effect
it
will
have
on
cytochrome
C.

Explain.
 
 
 
 2.

Even
if
you
got
lost
in
the
mitochondria,
you
should
be
able
to
tell
where
you
are
 in
the
picture
above
based
on
the
concentration
gradient
of
the
ions
depicted
as
 little
white
dots.

The
bottom
of
the
picture
represents
what
part
of
a
mitochondria
 (the
cytoplasm
outside,
the
inner
membrane
space,
or
the
mitochondrial
matrix)?
 
 
 
 Bio141 Respiration Problem Set 
 
 3.At
Complex
IV,
the
electrons
are
finally
handed
off
to
the
final
electron
acceptor,
 oxygen,
producing
water
(I
above).

Now
that
you
have
seen
the
whole
process
of
 cellular
respiration,
draw
a
rough
diagram
explaining
why
cellular
respiration
is
 named
after
our
normal
respiration
(i.e.
breathing
in
and
out),
indicating
in
your
 diagram
where
carbon
dioxide
is
created
and
oxygen
required.



 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Bio141 Respiration Problem Set 
 
 
 
 
 
 
 
 M
 P
 
 
 
 
 O
 
 
 
 
 
 
 
 
 
 
 1.
Name
the
labeled
structures
above.

 
 
 
 
 2.
Briefly
summarize
how
M
converts
P
into
O.
 
 
 
 3.
What
is
this
type
of
phosphorylation?
How
is
it
different
then
substrate‐level
 phosphorylation?
 
 
 
 In
your
diagram
comparing
cellular
respiration
to
actual
respiration
,
indicate
where
 substrate‐level
phosphorylation
is
found.

 
 
 
 
 
 
 
 
 
 Bio141 Respiration Problem Set 
 
 Case
Study:
Tylenol
Killer
 
 (The
following
is
based
on
true
events
that
took
place
in
Chicago
in
1982.)

 
 In
a
major
metropolitan
area,
seven
unusual
deaths
have
been
reported
that
all
 involved
individuals
taking
Tylenol
before
becoming
dizzy,
confused,
short
of
 breath,
nauseas,
and
ultimately
unresponsive.
It
is
your
job
to
use
your
knowledge
 of
biology
to
determine
what
caused
their
deaths.
 
 At
first,
you
receive
the
results
of
an
autopsy:
 
 • Immediate
cause
of
death
was
hypoxia
(suffocation
or
lack
of
oxygen),
 specifically
histotoxic
hypoxia.

 • Tissue
sections
from
heart,
lung,
kidney,
and
liver
all
show
massive
cell
 death.
Staining
with
specific
dyes
showed
major
mitochondrial
damage
 within
the
affected
tissues.

 • Oxygen
levels
in
the
patients’
blood
were
approximately
110
mm
Hg
(normal
 range
is
75
–
100
mm
Hg).
 
 
 If
you
had
to
predict
why
massive
cell
death
occurred
in
these
patients,
what
cell
 function
might
you
suggest
was
interrupted?
Would
loss
of
this
function
cause
death
 for
these
patients?
Why?
 
 
 
 
 
 Next,
You
receive
a
breakdown
of
the
concentration
of
important
metabolites
 found
within
the
cell:
 
 Detailed
analysis
of
the
damaged
cells
showed
that
ATP
levels
in
the
mitochondria
 were
very
low.
Levels
of
pyruvate
and
acetyl
coenzyme
A
(CoA)
were
normal.
 
 
 
 
 
 
 
 
 
 
 
 
 Bio141 Respiration Problem Set 
 For
each
metabolite
listed
in
the
table,
describe
its
role
in
cellular
respiration.
Are
 they
substrates
or
products?
What
is
their
main
function?
 
 
 Give
a
hypothesis
for
why
certain
metabolites
are
abnormal
in
the
victims.
Use
 reasoning
to
support
this
idea,
and
explain
what
might
be
occurring
to
stop
a
 normal
cell
process
and
cause
these
results.

 
 
 
 
 
 
 
 
 Lastly,
you
receive
a
toxicology
report,
which
indicates
the
presence
of
 cyanide
in
the
patients’s
bodies.
Cyanide
binds
the
iron
in
the
heme
group
in
 Complex
IV
(cytochrome
c
oxidase)
of
the
ETC,
thus
acting
as
a
noncompetitive
 inhibitor,
preventing
electrons
from
being
accepted
by
O2.


 
 How
does
this
knowledge
work
with
your
theory?
What
effect
does
cyanide
have
on
 the
electron
transport
chain
and
ultimately
the
production
of
ATP?
 
 
 
 
 
 Explain
why
patients
died
of
lack
of
oxygen
when
the
oxygen
levels
in
their
blood
 were
normal.
 
 
 
 What
might
be
a
possible
antidote
for
cyanide
poisoning?
Would
giving
victims
 more
oxygen
be
effective?

 
 
 
 
 
 
 
 
 
 Johnson
and
Johnson
offered
a
$100,000
dollar
reward
for
the
capture
of
the
 “Tylenol
Killer”
which
still
remains
unclaimed
today.
 
 
 Bio141 Respiration Problem Set 
 
 
 Adapted
from:
“The
Mystery
of
the
Seven
Deaths:
A
Case
Study
in
Cellular
Respiration”
by
Michaela
A.
 Gazdik,
Biology
Department,
Ferrum
College,
Ferrum
VA.
 Draw to learn: It is a common misconception that prokaryotes can’t undergo the final stages of respiration because they lack mitochondria. Compare the electron transport chain of both a prokaryote and a eukaryote by drawing their components and relative location in each type of cell. Be sure to include the location of the proton gradient and label where all necessary proteins and substrates (ADP, Pi, NADH etc.) would be found. Practice Exam questions: Pyruvate (pyruvic acid), the final product of glycolysis, has to enter the mitochondria to participate in the Kreb’s cycle. Which of the following statements about its entry is true and which is false? If false, correct it so that it is true. 1. Pyruvate moves by facilitated diffusion that goes against the concentration 
 Bio141 Respiration Problem Set 
 gradient. 2. Pyruvate is a lipid soluble molecule moving down its concentration gradient. 3. There must be transport molecules in the mitochondrial membrane. 4. The concentration of pyruvate is likely to be higher inside the mitochondrion than outside. 5. During aerobic respiration, electrons travel downhill from foodNADH electron transport chainoxygen. 6. Prokaryotes don’t do glycolysis because they lack mitochondrial membranes. 7. Photosynthesis is to cellular respiration as _________. a. exergonic is to endergonic. b. amino acids are to carbohydrates. c. increasing entropy is to decreasing entropy. d. anabolic is to catabolic. e. none of the above. 8. Rank the following compounds according to their oxidation state from LEAST oxidized to MOST oxidized: a. carbon dioxide, pyruvate, glucose b. glucose, carbon dioxide, pyruvate c. pyruvate, carbon dioxide, glucose, d. pyruvate, glucose, carbon dioxide e. glucose, pyruvate, carbon dioxide 9. The Krebs cycle yields NADH and FADH2 but not ATP or GTP. 10. Every reaction in cellular respiration is spontaneous. 
 Bio141 Respiration Problem Set 
 11. One of the reasons that glycolysis is believed to be one of the most ancient of metabolic processes is that glycolysis neither uses nor needs O2. 12. Glycolysis occurs in the mitochondria of eukaryotic cells and in the cytoplasm of prokaryotic cells. 13. During aerobic respiration, energy is gently transferred from food molecules to ATP molecules; during photosynthesis, light energy is used to generate ATP molecules which are used to create food molecules. 14. Which of the following molecules does not cross the inner membrane of the mitochondria? a. ATP b. acetyl-CoA c. pyruvate d. oxygen 15. The chemical 2,4 dinitrophenol (DNP) is used in the manufacturing of dyes, wood preservatives, explosives, and insect control substances, and as a photographic developer. Products containing DNP are toxic because DNP uncouples oxidative phosphorylation. In a cell exposed to DNP, how many ATP molecules would be generated per molecule of glucose? a. 2 b. 4 c. 36 d. 38 e. 24 16. A biochemist wants to control the initial substrate-level phosphorylation that occurs in the tracheal cells of grasshoppers once glucose has crossed the plasma membrane. This means that he will a. have to prevent cAMP from entering the tracheal cells. b. have to prevent pyruvate reduction from occurring. c. have to prevent glycolysis from occurring in the mitochondria. d. have to prevent glycolysis from occurring in the cytoplasm. e. have to prevent aerobic respiration in the cytoplasm. 
 Bio141 Respiration Problem Set 
 For
your
discussion…
 http://www.newscientist.com/channel/health/mg19325874.700‐cheap‐safe‐drug‐ kills‐most‐cancers.html
 
 Cheap,
'safe'
drug
kills
most
cancers
 
 



*
20
January
2007
 



*
NewScientist.com
news
service
 



*
Andy
Coghlan
 
 IT
SOUNDS
almost
too
good
to
be
true:
a
cheap
and
simple
drug
that
kills
almost
all
 cancers
by
switching
off
their
"immortality".
The
drug,
dichloroacetate
(DCA),
has
 already
been
used
for
years
to
treat
rare
metabolic
disorders
and
so
is
known
to
be
 relatively
safe.
It
also
has
no
patent,
meaning
it
could
be
manufactured
for
a
fraction
 of
the
cost
of
newly
developed
drugs.
 
 Evangelos
Michelakis
of
the
University
of
Alberta
in
Edmonton,
Canada,
and
his
 colleagues
tested
DCA
on
human
cells
cultured
outside
the
body
and
found
that
it
 killed
lung,
breast
and
brain
cancer
cells,
but
not
healthy
cells.
Tumours
in
rats
 deliberately
infected
with
human
cancer
also
shrank
drastically
when
they
were
fed
 DCA‐laced
water
for
several
weeks.
 
 DCA
attacks
a
unique
feature
of
cancer
cells:
the
fact
that
they
make
their
energy
 throughout
the
main
body
of
the
cell,
rather
than
in
distinct
organelles
called
 mitochondria.
This
process,
called
glycolysis,
is
inefficient
and
uses
up
vast
amounts
 of
sugar.
Until
now
it
had
been
assumed
that
cancer
cells
used
glycolysis
because
 their
mitochondria
were
irreparably
damaged.
However,
Michelakis's
experiments
 prove
this
is
not
the
case,
because
DCA
reawakened
the
mitochondria
in
cancer
 cells.
The
cells
then
withered
and
died
(Cancer
Cell,
DOI:
 10.1016/j.ccr.2006.10.020).
 
 Michelakis
suggests
that
the
switch
to
glycolysis
as
an
energy
source
occurs
when
 cells
in
the
middle
of
an
abnormal
but
benign
lump
don't
get
enough
oxygen
for
 their
mitochondria
to
work
properly
(see
Diagram).
In
order
to
survive,
they
switch
 off
their
mitochondria
and
start
producing
energy
through
glycolysis.
 
 Crucially,
though,
mitochondria
do
another
job
in
cells:
they
activate
apoptosis,
the
 process
by
which
abnormal
cells
self‐destruct.
When
cells
switch
mitochondria
off,
 they
become
"immortal",
outliving
other
cells
in
the
tumour
and
so
becoming
 dominant.
Once
reawakened
by
DCA,
mitochondria
reactivate
apoptosis
and
order
 the
abnormal
cells
to
die.
 “Once
reawakened
by
DCA,
mitochondria
order
the
abnormal
cancer
cells
in
a
 tumour
to
die”
 
 
 Bio141 Respiration Problem Set 
 "The
results
are
intriguing
because
they
point
to
a
critical
role
that
mitochondria
 play:
they
impart
a
unique
trait
to
cancer
cells
that
can
be
exploited
for
cancer
 therapy,"
says
Dario
Altieri,
director
of
the
University
of
Massachusetts
Cancer
 Center
in
Worcester.
 
 The
phenomenon
might
also
explain
how
secondary
cancers
form.
Glycolysis
 generates
lactic
acid,
which
can
break
down
the
collagen
matrix
holding
cells
 together.
This
means
abnormal
cells
can
be
released
and
float
to
other
parts
of
the
 body,
where
they
seed
new
tumours.
 
 DCA
can
cause
pain,
numbness
and
gait
disturbances
in
some
patients,
but
this
may
 be
a
price
worth
paying
if
it
turns
out
to
be
effective
against
all
cancers.
The
next
 step
is
to
run
clinical
trials
of
DCA
in
people
with
cancer.
These
may
have
to
be
 funded
by
charities,
universities
and
governments:
pharmaceutical
companies
are
 unlikely
to
pay
because
they
can't
make
money
on
unpatented
medicines.
The
pay‐ off
is
that
if
DCA
does
work,
it
will
be
easy
to
manufacture
and
dirt
cheap.
 
 Paul
Clarke,
a
cancer
cell
biologist
at
the
University
of
Dundee
in
the
UK,
says
the
 findings
challenge
the
current
assumption
that
mutations,
not
metabolism,
spark
off
 cancers.
"The
question
is:
which
comes
first?"
he
says.
 
 
 
 ...
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This note was uploaded on 10/17/2011 for the course BIO 141 taught by Professor Dr.cafferty during the Fall '11 term at Emory.

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