Name:

Protein Synthesis and Point Mutations

(changes that occur only at one point on the DNA)

Here is your ORIGINAL DNA sequence:

AATGCCAGTGGTTCGCAC

1)  Give the base sequence of the complementary strand of DNA.

2)  Give the base sequence of the mRNA read from the ORIGINAL DNA strand.

3)  What protein fragment would this mRNA code for?

4)  Use the chart on the back of this paper to see what kind of hair (protein) this person would have? ______

**Now let’s have a mutation. When one base is changed to another, it is called a substitution mutation. How does this affect the resulting protein? Let’s find out.

5)  If the fourth nucleotide in the original DNA strand were changed form G to C, what would the resulting mRNA look like?

6)  What would the resulting protein look like?

7)  Use the chart on the back of this paper to see what kind of hair (protein) this person would have after the mutation occurred? ______

**Another type of mutation is called an frameshift mutation. That is when an extra base is inserted or deleted in the DNA strand.

8)  (Insertion mutation) If a G were added to the original DNA strand after the third nucleotide, what would the resulting mRNA strand look like?

9)  What would the resulting protein look like?

10) Use the chart on the bottom of this paper to see what kind of hair (protein) this person would have after the mutation occurred? ______

11) (Deletion mutation) If the third nucleotide were deleted (remove the “T”) from the original DNA strand, what would the resulting mRNA strand look like?

12) What would the resulting protein look like?

13) Use the chart on the bottom of this paper to see what kind of hair (protein) this person would have after the mutation occurred? ______

14) Explain how a protein can be altered, based on the above problems. What effect could this change have on a person?

15) Explain why controlling the proteins in an organism controls the organism’s characteristics.

Protein Fragment Chart.

Leu-arg-ser-pro-ser-val / Curly hair
Leu-gly-ser-pro-ser-val / Curly hair
Leu-pro-val-thr-lys-arg / Thin hair
Phe-gly-his-glu-ala- / No hair