Student Exploration: Building DNA
Vocabulary: double helix, DNA, enzyme, mutation, nitrogenous base, nucleoside, nucleotide,
replication
Prior knowledge Questions (Do these BEFORE using the Gizmo)
DNA is an incredible molecule that forms the basis of life on Earth DNA molecules contain
instructions for building every living organism on Earth, from the tiniest bacterium to a massive
blue whale DNA also has the ability to replicate, or make copies of itself. This allows living
things to grow and reproduce
Look at the DNA molecule shown at right. What does it look like?
This shape is called a double helix
2. Based on this picture, how do you think a DNA molecule makes a
copy of itself? (Hint Look at the bottom two "rungs' of the ladder)

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein