DRNA+HW+CH

=__**DNA Review**__= =__**SCI Human Biology - 2**____**Assigned: 5/9 Due: 5/12**__= Chapter 21 DNA Biology


 * complementary paired bases
 * A pairs with T, by forming two hydrogen bonds, and G pairs with C, by forming three hydrogen bonds, or vice versa. This is called complementary paired bases.
 * template
 * the double-stranded structure of DNA allows each original strand to serve as a template (mold) for the formation of a complementary new strand.
 * mutation
 * A replication error that persists is a mutation, a permanent change in the sequence of bases that can possibly cause a change in the phenotype and introduce variability.
 * messenger RNA
 * Messenger RNA is produced in the nucleus, and a portion of DNA also serves as a template for its production. tRNA transfers amino acids to the ribosomes, where the amino acids are joined, forming a protein. There are 20 different types of amino acids in proteins;therefore, at least 20 tRNAs must be functioning in the cell. Each type of tRNA carries only one type of amino acid.
 * DNA replication
 * The process of copying a DNA helix is called DNA replication.
 * transcription
 * the second step of gene expression. during transcription, a strand of mRNA forms that is complementary to a portion of DNA
 * translation
 * Translation means to put information into a different language. Protein synthesis requires the process of translation
 * codon
 * Each three letter (base) unit of an mRNA molecule is called a codon.

1. How does the structure of DNA allow it to be replicated?**
 * Questions
 * DNA strands unzip, and new complementary strand forms opposite each old strand, resulting in two identical DNA molecules.
 * 2. How is the structure of RNA similar to, but also different from DNA? (THIS IS A LONG ANSWER SEE TABLE 21.1)**
 * DNA is a double helix. it is imposed of two strands that spiral about each other. Each strand is a polynuceotide because it is composed of a series of nucleotides. When the helix is unwound, a ladder configuration shows that the supports that the supports are composed of sugar (S) and phosphate (P) molecules and the rungs are complementary bases.
 * 3. If a strand of DNA was GCCATGACC what would the complementary DNA strand be?**
 * CGGTACTGG
 * 4. If a strand of DNA was GCCATGACC what would the complementary mRNA strand be?**
 * CGGUACUGG
 * 5. What is the structure of a protein?**
 * The primary structure of a protein is the sequence of its amino acids. The secondary structure can be either a helix or pleated sheet. The tertiary structure is the final three dimensional shape.
 * 6. What functions do proteins perform?**
 * Proteins determine structure and function of the various cells in the body
 * 7. If a mRNA had the codon sequence AUU GCG UGG, name the three amino acids that would be linked.**
 * Threonine, Caline, Lysine
 * 8. What evidence with respect to DNA suggests that all living things are related and share a common ancestor?**
 * Comparative genomics is a way to determine how species have evolved and how genes and non coding regions of the genome function.
 * 9. Where does transcription occur and what is the product?**
 * Occurs in the nucleus. the DNA triplet code is passed to an mRNA that contains codons. Introns are removed from mRNA during mRNA processing.
 * 10. Where does translation occur and what is the product?**
 * Occurs in the Cytoplasm at the ribosimes. tRNA molecules bind to their amino acids, and then their anticodons pair with mRNA codons.