BIO181 Exam 5 Study Guide - Chapter 14

Chapter 14 Study Guide

1. DNA vs. RNA

• Compare and contrast DNA and RNA (structure, function, location, etc.)

2. DNA Structure

• Draw and explain the complete structure of DNA including:
  • Double helix.
  • Nitrogenous bases.
  • Sugar-phosphate backbone.
  • Hydrogen bonds.
  • Phosphodiester bonds.

3. Nitrogenous Bases

• Identify the four nitrogenous bases in DNA.
  • Adenine (A)
  • Guanine (G)
  • Cytosine (C)
  • Thymine (T)
• Identify the four nitrogenous bases in RNA.
  • Adenine (A)
  • Guanine (G)
  • Cytosine (C)
  • Uracil (U)

4. DNA Replication Timing

• Identify the specific step or phase of the cell cycle when DNA replication is completed.

5. Goal of DNA Replication

• Describe the primary goal or purpose of DNA replication.

6. DNA Molecules After Replication

• Determine the number of DNA molecules present at the end of replication.
• Specify the percentage of old (template) and new (synthesized) DNA in each resulting molecule.

7. Base Pairing

• Describe base pairing rules in DNA.
  • A pairs with T.
  • G pairs with C.
• Explain how base pairing differs in RNA.
  • A pairs with U.

8. DNA and RNA Nucleotides

• Draw and label the components of DNA and RNA nucleotides.
  • Nitrogenous base
  • Pentose sugar (deoxyribose or ribose)
  • Phosphate group

9. DNA Double Helix Structure

• Draw the DNA double helix.
• Illustrate hydrogen bonds between nitrogenous bases.
• Illustrate phosphodiester bonds in the backbone.
• Describe the overall structure.

10. DNA Replication Process

• Draw the process of DNA replication.
• Include all necessary enzymes.
• Describe the function/role of each enzyme like:
  • Helicase
  • Primase
  • DNA polymerase
  • Ligase

11. Term Matching

• Match the correct term to each definition:
  • The process by which new molecules of DNA are formed is called:
    • bd. replication
  • Strands of DNA are held together by hydrogen bonds between the:
    • ae. nitrogenous bases
  • The sugar in RNA is:
    • e. ribose
  • The sugar in DNA is:
    • ac. deoxyribose
  • Nucleotides come in four different forms; the __ are the parts of the nucleotides that can vary.
    • ae. nitrogenous bases

12. DNA Arrangement

• Describe the arrangement of the sides (strands) of the DNA molecule (e.g., antiparallel).

13. Guanine Percentage

• If a DNA molecule is 40% thymine (T), calculate the expected percentage of guanine (G).
  • Since A=T, then Adenine is also 40%. That means A+T = 80%. Since A+T+C+G = 100%, then C+G = 20%. Also, since C=G, then Guanine is 10%.

14. Unique RNA Molecule

• Identify the molecule found in RNA but not DNA.
  • Uracil

15. Linear Chromosome Maintenance

• Explain how the ends of linear chromosomes are maintained, referencing the relevant enzyme.
  • Telomeres and Telomerase.

16. DNA Segment Connection

• Name the enzyme that covalently connects segments of DNA.
  • DNA Ligase

17. Leading vs. Lagging Strands

• Explain how the leading and lagging strands differ during DNA replication.
  • Leading strand is synthesized continuously.
  • Lagging strand is synthesized discontinuously in Okazaki fragments.

18. Hershey and Chase Experiment

• Explain how the Hershey and Chase experiments confirmed that DNA was the hereditary material.
• Mention the key finding from their experiment.
  • Radioactive phosphorus (^{32}P) was found in the infected cells, indicating DNA was the hereditary material.

19. Complementary DNA Sequence

• If one strand of DNA has the sequence TAGCA, determine the sequence of the complementary strand.
  • ATCGT

20. Antiparallel DNA Strands

• Explain what is meant by "antiparallel" regarding the strands that make up DNA.
  • One strand runs 5' to 3' and the other runs 3' to 5'.

21. DNA Strand Elongation

• Identify the enzyme that catalyzes the elongation of a DNA strand in the 5' to 3' direction.
  • DNA polymerase

22. DNA Wrapping in Eukaryotes

• In eukaryotes, describe what the DNA is wrapped around.
  • Histones

23. Replication Fork Proteins

• Name the kinds of proteins that are involved during the formation of the replication fork.
  • Helicase, single-strand binding proteins, topoisomerase

24. Primase Function

• Describe what the enzyme primase synthesizes during DNA replication.
  • RNA primer