Unit 2 Genetics: DNA & RNA Quiz Study Guide Quiz Date: Friday October 30, 2015 *START STUDYING IMMEDIATELY!!!!* SB2B: Explain the role of DNA in storing and transmitting cellular information. 1. State a role (FUNCTION) for each of three different types of enzymes in DNA replication. a. DNA helicase: b. DNA polymerase: c. DNA ligase: 2 . Which of the following is the correct base-pairing rule for DNA? A. A-U; C-G B. A-G; T-C C. A-T; G-C D. A-C; T-G 3. The letters “DNA” stand for Deoxyribonucleic acid. 4. DNA is composed of smaller subunits know as Nucleotides. 5. The three parts of a nucleotide are Sugar, phosphate, and a nitrogen base. 6. The four nitrogen bases that are found in DNA are Adenine, cytosine, guanine, and thymine. 7. DNA looks like a ladder twisted into a shape known as a double helix 8. The two molecules that make up the sides of the ladder or the side portion of a DNA molecule are Sugars and phosphates. 9. The molecules that meet across the middle, forming the steps of the “ladder’” are known as Nitrogen bases. 10. According to Chargaff’s rules, the percentages of adenine are equal to those of thymine and the percentages of cytosine are equal to those of guanine in the DNA molecule. 11. The nitrogen bases are held together in the center of the molecule by Hydrogen Bonds. 12. The type of sugar found in DNA is Deoxyribose. 13. If the sequence on the right hand side of the DNA molecule was TAGGCTCA, the complimentary side would have a sequence of ATCCGAGT. 14. Label the parts of the drawing below. Include all of these terms: nucleotide, phosphate, sugar, nitrogen base, hydrogen bond, covalent bond, purine, pyrimidine, adenine, thymine, cytosine, and guanine. 15. The process in which DNA builds an exact duplicate of itself is known as DNA Replication. 16. What is the primary function of DNA? The primary function of DNA is to store information that tells the cells which proteins to make. 17. Why is it so important that the DNA molecule be able to make copies of itself? Just prior to cell division, the DNA must replicate so that each new daughter cell receives an exact copy of the genome for that cell. All cells that divide to form new cells must pass exact copies of their DNA to offspring cells. 18. During replication, the two nucleotide chains separate and each chain serves as a template for a new nucleotide chain. This process is known as DNA Replication. 19. During replication, enzymes called DNA Helicase untwist the double helix, separating the two parental strands. 20. Enzymes called DNA Polymerase move along the separated strands assembling the new chains of DNA. 21. The letters “RNA” stand for Ribonucleic Acid. 22. In RNA, adenine always pairs with the nitrogen base known as Uracil. 23. List three ways that DNA is different from RNA: (1) DNA HAS THE SUGAR DEOXYRIBOSE AND RNA HAS THE SUGAR RIBOSE. (2) DNA IS DOUBLE STRANDED AND RNA IS SINGLE STRANDED. (3) DNA HAS THE NITROGEN BASE THYMINE. RNA HAS N THYMINE, BUT HAS URACIL INSTEAD. 24. There are three kinds of RNA. Messenger RNA carries the information from the nucleus to the ribosome’s in the cytoplasm. Transfer RNA reads the message and binds to the specific Amino Acids to make the protein. Ribosomal RNA is the most abundant form of RNA and makes up ribosome’s. 25. The process of making a strand of RNA from a strand of DNA is called Transcription. 26. The sequence of nucleotides in mRNA is Translated into a sequence of Amino Acids. 27. A group of 3 nitrogen bases forms a Codon. 28. Translation occurs in the ribosomes in the cytoplasm. The DNA in the nucleus tells the ribosomes which proteins to make and how to make them. In the nucleus, DNA transcribes RNA. The RNA is then sent to the cytoplasm in the form of mRNA. A combination of three nitrogen bases is used as a code for each amino acid. This group of three bases is called a codon. Each codon calls for one amino acid. It takes many amino acids to form a protein. These amino acids are transported to the ribosomes by tRNA to form proteins 29. If the sequence on the DNA molecule calls for a protein with the following DNA codons, (1) what would be the sequence on the mRNA, (2) what would be the sequence on the tRNA, and (3) what would be the amino acid sequence of the protein being made? DNA TAC mRNA TTA AUG CAA AAU ACC GUU ATA UGG ATT UAU UAA tRNA UAC UUA CAA ACC AUA AUU Amino Acids: INITIATOR, ASPARAGINE, VALINE, TRYPTOPHAN, TYROSINE, TERMINATOR