Bio 544
Lab Investigation
Name:
Relating Amino Acids Sequences to Evolutionary Relationships
Adapted from Modern Biology, Albert Towle, Holt Rhinehart &Winston, 1999.
Aim:
a) To observe the amino acid sequence of hemoglobin and cytochrome c in several
species.
b) To compare the amino acid sequences of the same protein in different species.
c) To deduce evolutionary relationships among species.
Background:
1) Hemoglobin and cytochrome c are two proteins commonly studied by scientists
attempting to deduce evolutionary relationships from differences in amino acid
sequence.
2) Researchers believe that the greater the similarity that exists between the amino acid
sequences of two species, the more closely related the two species are evolutionarily.
3) The greater the differences that exist in the amino acid sequences of two species, the
more distantly related the two species are.
4) The longer the two species have been diverging from a common ancestor, the greater
the difference in their amino acid sequences. This principal is based on the assumption
that the rate of change of the specific amino acid sequence is the same in all species.
Data:
Table 1: Cytochrome c
- A protein found in the mitochondria of many species. It consists of a chain of 104 amino
acids.
- The table represents parts of the amino acid sequence of cytochrome c in nine different
vertebrate species. The first column identifies the position of these sequences in the
chain (#/104). The letters (ex. Gln, Ala) identify the name of the specific amino acid in
the chain for each species.
Table 2 : Hemoglobin
- An oxygen-carrying molecule found in red blood cells.
- The table represents a portion of the chain representing hemoglobin between amino
acids #87 and 116. The first column identifies the position of these sequences in the
chain (#/116). The letters (ex. Gln, Ala) identify the name of the specific amino acid in
the chain for each species.
Table 1 - Cytochrome c Amino Acid Sequence
#
42
43
44
46
47
49
50
53
54
55
56
57
58
60
61
62
63
64
65
66
100
101
102
103
104
horse
Gln
Ala
Pro
Phe
Thr
Thr
Asp
Lys
Asn
Lys
Asn
Ile
Thr
Lys
Glu
Glu
Thr
Leu
Met
Glu
Lys
Ala
Thr
Asn
Glu
chicken
Gln
Ala
Glu
Phe
Ser
Thr
Asp
Lys
Asn
Lys
Gly
Ile
Thr
Gly
Glu
Asp
Thr
Leu
Met
Glu
Asp
Ala
Thr
Ser
Lys
tuna
Gln
Ala
Glu
Tyr
Ser
Thr
Asp
Lys
Ser
Lys
Gly
Ile
Val
Asn
Asn
Asp
Thr
Leu
Met
Glu
Ser
Ala
Thr
Ser
-
frog
Gln
Ala
Ala
Phe
Ser
Thr
Asp
Lys
Asn
Lys
Gly
Ile
Thr
Gly
Glu
Asp
Thr
Leu
Met
Glu
Ser
Ala
Gly
Ser
Lys
human
Gln
Ala
Pro
Tyr
Ser
Thr
Ala
Lys
Asn
Lys
Gly
Ile
Ile
Gly
Glu
Asp
Thr
Leu
Met
Glu
Lys
Ala
Thr
Asn
Glu
shark
Gln
Ala
Gln
Phe
Ser
Thr
Asp
Lys
Ser
Lys
Gly
Ile
Thr
Gln
Gln
Glu
Thr
Leu
Arg
Ile
Lys
Thr
Ala
Ala
Ser
turtle
Gln
Ala
Glu
Phe
Ser
Thr
Asp
Lys
Asn
Lys
Gly
Ile
Thr
Gly
Glu
Glu
Thr
Leu
Met
Glu
Asp
Ala
Thr
Ser
Lys
monkey
Gln
Ala
Pro
Tyr
Ser
Thr
Ala
Lys
Asn
Lys
Gly
Ile
Ile
Gly
Glu
Asp
Thr
Leu
Met
Glu
Lys
Ala
Ala
Asn
Glu
rabbit
Gln
Ala
Tyr
Pro
Ser
Thr
Asp
Lys
Asn
Lys
Gly
Ile
Thr
Gly
Glu
Asp
Thr
Leu
Met
Glu
Lys
Ala
Thr
Asn
Glu
Table 2 - Hemoglobin Amino Acid Sequences
#
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
human
Thr
Leu
Ser
Glu
Leu
His
Cys
Asp
Lys
Leu
His
Val
Asp
Pro
Glu
Asn
Phe
Arg
Leu
Leu
Gly
Asn
Val
Leu
Val
Csy
Val
Leu
Ala
His
chimpanzee
Thr
Leu
Ser
Glu
Leu
His
Cys
Asp
Lys
Leu
His
Val
Asp
Pro
Glu
Asn
Phe
Arg
Leu
Leu
Gly
Asn
Val
Leu
Val
Cys
Val
Leu
Ala
His
gorilla
Thr
Leu
Ser
Glu
Leu
His
Cys
Asp
Lys
Leu
His
Val
Asp
Pro
Glu
Asn
Phe
Lys
Leu
Leu
Gly
Asn
Val
Leu
Val
Cys
Val
Leu
Ala
His
monkey
Gln
Leu
Ser
Glu
Leu
His
Cys
Asp
Lys
Leu
His
Val
Asp
Pro
Glu
Asn
Phe
Lys
Leu
Leu
Gly
Asn
Val
Leu
Val
Cys
Val
Leu
Ala
His
horse
Thr
Leu
Ser
Glu
Leu
His
Cys
Asp
Lys
Leu
His
Val
Asp
Pro
Glu
Asn
Phe
Arg
Leu
Leu
Gly
Asn
Val
Leu
Ala
Leu
Val
Val
Ala
Arg
Analysis and Conclusions:
Part A: Cytochrome c
1) Make a table to record your data in your lab report. Label the columns of your data
table `species’ and `number of differences from human cytochrome c '. For each
vertebrate species, count the amino acids in the sequence that are different from the
human sequence. List these in your data table. Do not forget to give your table a title.
2) List the eight vertebrate sequences in descending order according to the degree of
similarity of their cytochrome c with that of humans.
3) According to your analysis of the amino acid sequences, which species listed is the most
closely related to humans? Were you surprised by your results? Why or why not?
4) According to your analysis of the amino acid sequences, which species listed is the least
closely related to humans? Were you surprised by your results? Why or why not?
Part B: Hemoglobin
1) In you lab report, make a table to record your data. Label the columns of your data table
`species’ and `number of differences from human hemoglobin '. For each vertebrate
species, count the amino acids in the sequence that are different from the human
sequence. List these in your data table as you did for Part A. Do not forget to give your
table a title.
2) List the five vertebrate sequences in descending order according to the degree of
similarity of their hemoglobin with that of humans.
3) According to your analysis of the amino acid sequences, which species listed is the most
closely related to humans? Were you surprised by your results? Why or why not?
4) According to your analysis of the amino acid sequences, which species listed is the least
closely related to humans? Were you surprised by your results? Why or why not?
Part C: Phylogenetic Tree
1) Compile the information for the cytochrome c data and create a phylogenetic tree that
would represent the differences and similarities between the nine vertebrate species.
2) Compile the information for the cytochrome c data and create a phylogenetic tree that
would represent the differences and similarities between the five vertebrate species.
Bio 504
Lab Investigation
Name:
Lab Report
Relating Amino Acids Sequences to Evolutionary Relationships
Part A: Cytochrome c
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Part B: Hemoglobin
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Part C: Phylogenetic tree
Cytochrome c
/3
Hemoglobin
/3