Protein Synthesis Poster

Introduction:

Scientists understand how chromosomes (containing DNA) can direct the formation of specific proteins outside the nucleus while still in the nucleus. In this activity, you will make a poster with models of DNA, RNA and amino acids to demonstrate how proteins are synthesized by a cell.

Background:

The molecules which make up DNA are deoxyribose, phosphoric acid and nitrogen bases. As you have learned, there are four nitrogen bases in DNA: A, C, G and T. One base and one phosphoric acid are bonded to a deoxyribose molecule to form a nucleotide. On the following pages, you will see the four possible nucleotides in DNA.

A DNA molecule is “ladder like” in shape. Deoxyribose and phosphoric acid molecules join to form the sides or uprights of the ladder. Nucleotide molecules join together by hydrogen bonds to form the rungs of the ladder.

Color Key:

1. Color in the molecules found on the last four pages of this packet. Use the following key:

Molecule Color

Deoxyribose pink

Ribose purple

Phosphoric acid black

Adenine blue

Cytosine green

Guanine yellow

Thymine red

Uracil brown

2. Cut out the 12 nucleotide models for DNA. CUT ONLY ALONG THE SOLID LINES.

3. Connect six nucleotides together to form a row in the following sequence from top to bottom:

Cytosine Let this represent the LEFT half

Thymine of a ladder molecule. This should

Guanine consist of one side or upright plus

Adenine six half rungs.

Guanine

Cytosine

4. Construct a circle one your poster board about three times as wide as the DNA chain is long. This will be your NUCLEUS. Please label it clearly. Glue down your nucleotide chain in the nucleus. Just above this chain, label it: DNA

5. Now, complete the right side of the DNA ladder by matching the bases of the remaining nucleotides to form complete rungs on your ladder. It may be necessary to flip molecules upside down in order to join certain base combinations. DO NOT glue this side of the chain to the paper, but tape its pieces together and place it in the nucleus so it pairs up with the complementary strand.

6. Your completed model should look like a ladder with matched bases as the rungs. Besides being shaped like a ladder, a DNA molecule is twisted. It looks like a spiral staircase. However, your paper model cannot show this.