Exam 2 Key

Exam 2 Key - Name
and
HUID
 
 
 
 Life Sciences...

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Unformatted text preview: Name
and
HUID
 
 
 
 Life Sciences 2 Midterm #2 Question # #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 #15 #16 Total 
 
 Points 
 1
 Name
and
HUID
 
 Two
Point
Questions
 
 
 
 2
 1) Over
the
first
ten
minutes
of
an
exercise
bout,
what
are
the
sources
of
the
energy
 used
for
skeletal
muscle
contraction
and
in
what
order
are
they
used?
(2
points)
 ATP,
PCr,
glycolysis
and
oxidative
phosphorylation
 0.5
point
for
each
 ‐0.5
if
in
incorrect
order;
0.25
points
for
anaerobic
metabolism
instead
of
glycolysis;
0.25
 points
for
aerobic
metabolism
instead
of
oxidative
phosphorylation
 2) What
is
the
net
ATP
production
during
each
of
the
following
processes
per
molecule
 of
glucose:
(2
points
total)
 a) Krebs
Cycle
 0.6
points
–
2
ATP;
credit
was
also
given
for
0
ATP

 b) Glycolysis
 0.6
points
–
2
ATP
 c) Oxidative
phosphorylation
 0.6
points
–
34
ATP

 
 3) Briefly
describe
the
energy
problem
the
brain
experiences
during
acute
starvation?
 (1
point)
How
is
this
problem
solved
in
the
short
term?
(1
point)
 1.0
points
–
during
starvation
the
brain
does
not
have
enough
glucose
to
maintain
its
 metabolic
rate.
1
point
–
the
body
converts
fatty
acids
into
ketone
bodies
which
the
brain
 can
use
as
fuel
 4) If
the
human
lung
has
the
same
surface
area
as
a
tennis
court,
how
many
tennis
 courts
would
a
horses
lung
cover
if
the
horse
weighs
8
times
as
much
as
a
human,
 and
assuming
that
lung
area
and
body
mass
scale
isometrically?
(2
points)
 2
points
–
4
or
82/3
 5) You
take
an
alternative
spring
break
to
Nepal
and
climb
Mount
Everest.

When
you
 get
close
to
the
peak,
you
need
supplemental
oxygen
to
proceed,
but
your
Sherpa
 continues
forward
without
assistance.

Describe
the
four
physiological
factors
that
 underlie
your
Sherpa’s
acclimatization
to
the
extreme
altitude
of
Everest.
(2
points)
 0.5
points
each
 Increased
ventilation
–
2‐3
L/min
higher
than
at
sea
level
 Chemoreceptors
become
more
responsive
to
PCO2
 Substantial
decline
in
PO2
stimulates
peripheral
chemoreceptors
 Kidneys
accelerate
the
production
of
erythropoietin
which
increases
the
number
of
 RBC’s
 Name
and
HUID
 
 
 
 
 
 3
 
 6) A
stroke
is
the
sudden
death
of
brain
cells
in
a
localized
area
due
to
inadequate
 blood
flow
that
restricts
the
oxygen
supply
to
that
region
of
the
brain?
How
would
a
 stroke
in
the
brainstem
differ
in
its
consequences
from
a
stroke
in
the
frontal
lobe
of
 the
cerbral
cortex?

(2
points)
 1
point
–
a
stroke
in
the
brainstem
will
affect
processes
that
are
necessary
for
life
 (respiration,
heart
rate
etc)
and
will
usually
be
fatal
1
point
–
a
stroke
in
the
frontal
lobe
 could
affect
the
part
of
the
brain
responsible
for
controlling
movements
and
planning
 behavior.
 7) List
two
structural
differences
between
the
fetal
and
adult
circulatory
system
in
the
 heart
that
change
at
birth.
(2
points)
 1
point
–
foramen
ovale;
1
point
–
ductus
arteriosus
 8) Concisely
describe
the
path
of
depolarization
in
the
heart,
include
where
the
signal
 for
contraction
starts
and
explain
why
it
is
functionally
important
that
thereis
a
 delay
between
where
depolarization
starts
in
the
atria
and
in
the
ventricles.
(2
 points)
 1
point:
SA
Node
(start
of
depolarization
of
the
atria)

AV
Node
(start
of
depolarization
of
 the
ventricles)

bundle
of
his

bundle
branches

purkinje
fibers
 1
point:
A
delay
occurs
between
the
AV
Node
and
the
SA
node
so
that
the
atria
can
contract
 and
push
their
contents
into
the
ventricles
prior
to
ventricular
contraction
beginning.
 Name
and
HUID
 
 
 
 
 
 4
 9) Draw
a
graph
to
label
and
illustrate
the
difference
between
stiffness
and
strength.
(2
 points)
 
 Strength
–
resistance
to
fracture;
where
the
failure
point
is
on
the
stress/strain
curve;
 Stiffness
–
resistance
to
deformation;
the
slope
of
the
stress/strain
curve
 10)What
is
the
encephalization
quotient
(EQ)
and
how
does
it
differ
between
an
 average
mammal,
a
chimpanzee
and
a
human?
(2
points)
 1
point
–
the
encephalization
quotient
is
the
ratio
of
the
observed
brain
mass
divided
by
 the
estimated
brain
mass.

1
point
–
The
encephalization
quotient
is
greater
in
a
human
 (5.1),
than
in
a
chimpanzee
(2.1),
than
it
is
in
an
average
mammal
(1.0).

Numbers
are
not
 necessary
for
a
correct
answer
but
if
they
give
incorrect
numbers
‐0.25
points.
 
 
 
 
 
 Name
and
HUID
 
 Five
Point
Questions
 
 
 
 5
 11)At
sea
level
the
atmospheric
pressure
is
760mmHg
and
the
air
is
composed
of
21%
 oxygen.
 a) What
is
the
partial
pressure
of
oxygen
in
the
atmosphere
at
sea
level?
(1
point)
 PO2sealevel
=
760mmHg
x
0.21
=
160
mmHg
(159.6
mmHg
exactly)
 b) What
is
the
approximate
partial
pressure
of
oxygen
in
the
alveoli
at
sea
level?
(1
 point)
 ~105mmHg
any
value
withing
110
–
100
should
be
accepted
for
full
credit
 c) List
two
reasons
there
is
a
difference
between
the
partial
pressure
of
the
oxygen
 in
the
atmosphere
and
the
partial
pressure
of
oxygen
in
the
lungs.
(2
points)
 1
point
–
air
entering
the
alveoli
is
humidified
 1
point
–
air
entering
the
alveoli
is
mixed
with
stale
air
that
was
not
expired
from
the
lungs
 d) What
is
the
approximate
partial
pressure
of
oxygen
in
the
mitochondria?
(1
 point)
 1
point
–
1
–
10
mmHg
 12)Draw
an
oxygen
saturation
curve
graph
with
the
curve
for
myoglobin
and
the
curve
 for
adult
hemoglobin.
Be
sure
to
label
the
axes.
(3
points)


 
 Name
and
HUID
 
 
 
 6
 
 b) What
structural
properties
account
for
the
difference
between
the
myoglobin
and
 hemoglobin
dissociation
curve?
(1
point)


 0.5
points
–
hemoglobin
is
a
tetramer
which
is
capable
of
bonding
to
four
oxygen
 molecules;
0.5
points
–
myoglobin
is
a
monomer
that
is
capable
of
binding
to
only
one
 molecule
of
oxygen

 c) What
is
the
functional
significance
of
the
differences
between
myoglobin
and
 hemoglobin
dissociation
curve?
(1
point)
 At
the
level
of
the
muscles
the
difference
in
the
curves
encourages
oxygen
to
disassociate
 from
hemoglobin
and
bind
to
myoglobin.
 13)Contrast
the
actions
of
insulin
and
glucagon
in
skeletal
muscle,
adipose
tissue
and
 the
liver.
(5
points)
 Insulin
has
the
following
effects:
 In
muscle
insulin
stimulates
the
conversion
of
glucose
to
glycogen,
allows
for
the
uptake
of
 glucose
and
amino
acids,
and
stimulates
the
formation
of
proteins
from
amino
acids
 In
adipocytes
insulin
stimulates
the
uptake
of
glucose
and
the
conversion
of
glucose
to
 triglycerides.
 In
the
liver
insulin
stimulates
the
uptake
of
glucose
and
the
conversion
of
glucose
to
 glycogen
and
fatty
acids.
 Glucagon
has
the
following
effects:
 In
the
liver
glucagon
stimulates
glycogenolysis
(the
breakdown
of
glycogen),
 gluconeogenesis
(the
formation
of
glucose
from
non‐carbohydrates)
and
ketone
formation.

 Name
and
HUID
 
 
 
 
 
 7
 14)Peak
stress
in
the
leg
bones
during
locomotion
is
predicted
to
increase
proportional
 to
body
mass
for
quadrupedal
(i.e.
four‐footed)
mammals.
Below
is
a
graph
from
a
 paper
on
bone
properties
and
body
size
(Biewener,
1982). 
 a) Estimate
the
slope
of
the
regression
line.
 Slope
approximately
0.75
 
 b) What
exponent
for
the
allometric
equation
would
you
expect
for
an
isometric
 relation
between
area
and
body
mass?
 Scales
to
the
2/3
 
 c) Does
the
graph
indicate
positive
or
negative
allometry
relative
to
your
isometric
 prediction
from
b)?
 Positive
allometry
 
 d) Does
your
answer
from
c)
imply
that
larger
animals
will
have
relatively
more
 slender,
stout
or
isometrically
similarly
shaped
leg
bones?

 Stouter
Legs
 
 e) What
bone
diameter
would
you
predict
for
a
formidable
rat,
with
a
body
mass
of
 1kg?
 3.56
mm
 
 
 
 
 
 Name
and
HUID
 
 
 
 8
 
 15)On
the
graph
below
add
lines
showing
the
pressure
in
the
pulmonary
artery
and
the
 pressure
in
the
right
ventricle
and
the
volume
in
the
right
ventricle
during
the
 cardiac
cycle.

(3
points)

During
which
phase(s)
in
the
diagram
below
is
the
heart
 isovolumetric?
(2
points)

 1
point
–
for
each
correctly
drawn
line
(red
pressure
in
the
right
ventricle,
light
purple
is
 pressure
in
the
pulmonary
artery
and
orange
is
volume
in
the
right
ventricle);
1
point
each
 –
the
heart
is
isovolumentric
during
phases
2
and
4
of
the
cardiac
cycle
 
 
 
 
 Name
and
HUID
 
 
 
 
 
 9
 16)Describe
the
role
of
chondrocytes
and
osteoblasts
in
the
growth
plate
of
a
long
bone.

 (2
points)
What
are
the
effects
of
the
sex
hormones
on
the
chondrocytes
and
 osteoblasts
in
growth?
(3
points)
 1
point
‐
chondrocytes
produce
cartilage
at
the
epiphyseal
end
of
the
growth
plate;
1
point
 –
osteoblasts
produce
bone
at
the
diaphysis
(metaphysis)
end
on
the
growth
plate;
2
points
 –
testosterone
stimulates
the
growth
of
chondrocytes
and
osteoblasts;
1
point
–
estrogen
 stimulates
the
osteoblast
growth
but
also
terminates
bone
growth
(termination
is
 optional?)
 ...
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