# Animal Metabolism Biology Lab Report Template

At extremely cold temperatures, ice crystals form, causing fatal cell rupture. At higher
BIO 3A LABORATORY
temperature a critical maximum temperature is generally reached, at which enzyme
Animal Metabolism
activities, and reaction rates, are maximized.
Beyond this temperature protein
denaturation results in decreased activity and ultimately death.
Objectives
• Determine the raw oxygen consumption of mice at two different ambient
Procedure A. Indirect respirometry of goldfish metabolism
temperatures.
The gill structures of most fishes are cover by an operculum. The operculum works in
• Calculate weight specific metabolic rate adjusted to STPD for a homeotherm
concert with the mouth and buccal cavity in moving water over the gills. The mouth
• Measure metabolic rate in a heterotherm, the goldfish, at different ambient
opens, the buccal cavity expands, the mouth closes, the operculum opens and the buccal
temperatures
cavity contracts. This forces water over gills where oxygen and carbon dioxide are
exchanged. If the volume of water is constant
during each of these cycles, then the rate of
Introduction
opercular pumping is proportional to the oxygen
In the reactions known as cellular respiration, oxygen is always reduced; it is the ultimate
demand.
Thus one could indirectly measure
+
proton (H
) acceptor in this process:
metabolic rate as opercular pumping rate.
→ 6CO
C
H
O
+ 6O
+ 6H
O
(1)
6
12
6
2
2
2
In this experiment you will measure the
opercular pumping rate of goldfish at three
Sometimes this occurs almost immediately (aerobic metabolism); occasionally it is
different temperatures.
delayed (anaerobic metabolism). Temperature can have a profound effect on the rate of
Figure 2. Operculum of a
metabolic reactions. In general, metabolic reactions are governed by the Q
rule. As
10
1. Place a goldfish into approximately 200 mL of water in a 250 mL beaker. Place the
temperature is increased by 10 degrees C the rate of the reaction will double. Your
beaker in the ice bath until the temperature has reach approximately 3 to 4 ˚C.
earlier labs involving proteins showed us the temperature sensitivity of enzyme-mediated
2. Remove the beaker gently and place it in a good viewing area. Extraneous stimulation
reactions. However, in animals with variable body temperatures (heterotherms), several
will cause to fish to not settle down. Use one of the ice containers to shield the fish
forms of an enzyme may exist (isoforms or isozymes).
Each of these forms may
from extraneous stimuli. Count the opercular pumping for 2 min (120 sec). Repeat
demonstrate maximum activity at a different temperature. Thus, the organism may be
this measurement two more times. Record your data in Table 1. Counters are
able to survive over a range of ambient (and body) temperatures. Another group of
available if needed.
animals puts a lot of energy (literally) into maintaining a constant body temperature. By
3. Place the beaker into a room temperature bath. When the temperature has reach the
doing this, they can minimize the number of forms of an enzyme required; in addition, if
ambient, let the system equilibrate for ten minutes.
these animals maintain a temperature slightly below the critical maximum (point of protein
4. Remove the beaker gently and place it in a good viewing area. Again, extraneous
denaturation) they can maximize the reaction rates (Q
rule). These organisms are
10
stimulation will cause to fish to not settle down. Use one of the ice containers to
called homeotherms.
shield the fish from extraneous stimuli. Count the opercular pumping for 2 min (120
sec). Repeat this measurement two more times. Record your data in Table 1.
Indirect measurement of metabolism in
5. Place the beaker into the 30 ˚C bath. When the temperature has reach bath
a heterotherm
temperature, let the system equilibrate for ten minutes.
Goldfish are heterothermic ectotherms.
6. Remove the beaker gently and place it in a good viewing area. Again, extraneous
Their body temperature is virtually identical
stimulation will cause to fish to not settle down. Use one of the ice containers to
to the water in which they live.
Small
shield the fish from extraneous stimuli. Count the opercular pumping for 2 min (120
variations in Tb can result from the
sec). Repeat this measurement two more times. Record your data in Table 1.
exploitation of the variable microhabitat in
7. Once you have completed all of your measurements, record all of your measurements
which they live. For instance, the area of
on the computer so that others can download the data.
water nearer the surface may be slightly
8. Using your data set, create a data table in Excel, in this table you should take the
warmer; water under plant leaves may be
average of the pumping rate at each temperature. Create a graph of opercular
cooler. However, in general, their Tb will
pumping rate vs. ambient temperature. Is there a significant difference between the
vary
through
the
daily
cycle.
The
average opercular pumping rate at the low temperature and the high temperature?
temperature-related metabolic response of
(hint: use the appropriate t-test!).
most ectotherms is linear over a range of
9. Using the whole class data set (download this) for the goldfish experiment, is there a
Figure 1. Heterotherm metabolism vs.
reasonable environmental temperatures.
temperature
significant difference between the average opercular pumping rate at the low
temperature and the high temperature? Construct a graph for this comparison also.
BIO 3A Lab: Animal Metabolism
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BIO 3A Lab: Animal Metabolism
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