Unit 2 Nucleic Acid Test Review KEY.pdf

Richardson Honors Biology Unit 2 Nucleic Acids Review Sheet KEY Test is on Wednesday, September 13th 1. Prior to the Hershey and Chase experiment, which macromolecule did scientists think would be the ‘genetic material’? WHY? Most scientists thought protein would prove to be the genetic material....

Richardson Honors Biology Unit 2 Nucleic Acids Review Sheet KEY Test is on Wednesday, September 13th 1. Prior to the Hershey and Chase experiment, which macromolecule did scientists think would be the ‘genetic material’? WHY? Most scientists thought protein would prove to be the genetic material. This is due to protein having 20 different monomer units versus DNA only having 4. 2. Hershey and Chase used viruses in their experiment. What two things a virus is made of? What is the chemical difference is between nucleic acids and proteins? A virus has a protective coat or shell and ‘genetic material’. Proteins contain sulfur (not found in DNA) and DNA contains phosphorous (not found in proteins). 3. What were the conclusions of the Hershey and Chase experiment? DNA is the genetic material, not proteins. 4. What are the three parts of a DNA nucleotide? Phosphate, 5-carbon sugar, nitrogenous base. 5. Draw a DNA nucleotide and label the 3 parts and the 3’ and 5’ carbons. 6. If your nucleotide above were to attach to a growing polymer of nucleotides, which end would be connected? The 5’ end, with the phosphate attached would connect to the existing chain. 7. What is the name of the protein that would make the connection between the nucleotide and the growing chain? DNA polymerase 8. What is the name of the bond that would form linking this nucleotide to the chain? Phosphodiester Bond 9. Let’s say the nucleotide you drew had the base adenine. Which base would it be connecting to in the middle? Thymine (T) 10. What is the name of the bond that would form between these two bases? How many of these bonds would form? Hydrogen bonds (h-bonds) connect the bases. A-T would have 2 h-bonds. (C-G has 3 h-bonds). 11. The ‘backbone’ of a DNA strand is made of which two parts of a nucleotide? Phosphate and Sugar. 12. Why is DNA called a ‘double helix’? DNA is made up of 2 (double) strands that twist (helix). 13. The two strands of a DNA molecule are said to be antiparallel. What does this mean? The two strands are parallel to one another, but they move in opposite directions. They are said to be antiparallel. 14. Complete the following table: Protein Function in DNA Replication Helicase Unzips the DNA double helix by breaking hydrogen bonds between base pairs. DNA Polymerase Adds new DNA nucleotides in 5’--> 3’ direction by using base-pair rules. Single-stranded binding Hold single stranded DNA open. proteins RNA Polymerase Starts a new chain because DNA polymerase can not start a new chain. However, adds (What is another name?) RNA nucleotides instead of DNA nucleotides. This stretch of RNA is called a primer. Also Known As: Primase. Ligase Connects strands 3’-5’ 15. Write the complimentary strand for the template strand given here: 3’ ATGATATG 5’ 5’ TACTATAC 3’ 16. DNA replication is said to be ‘semi-conservative’. What does this mean? When DNA replicates, it uses half of the original strand as a template. The new strand is then built onto this original strand. So the new double helix is made of one saved (conserved) and one new strand. Half (semi) old, half new. ‘semi- conservative’. There is a page 2! 17. Label the diagram to the right using each of following terms once only! a. Leading Strand e g b. Lagging Strand template c. Primer d. RNA Polymerase (what is another name for this molecule?) e. Nucleotides f. Replication Fork g. DNA Polymerase a h. Helicase h c f d b 18. What is the difference between a purine and a pyrimidine? Both are types of nitrogenous bases. A purine has two ring structures, and is therefore longer than a pyrimidine with only one ring structure. 19. Which bases are purines? Which are pyrimidines? Adenine (A) and Guanine (G) are purines Thymine (T) and Cytosine (C) are pyrimidines 20. Using Chargaff’s Rules, determine how many thymine, cytosine, and guanine there would be if the number of adenines is 22%. Thymine = 22% Cytosine = 28% Guanine = 28% 21. What are the differences between DNA and RNA? DNA is double stranded, RNA is usually only single stranded. RNA has the sugar ribose, DNA has the sugar deoxyribose. RNA has the base uracil in place of DNA’s thymine. RNA has several types and purposes (mRNA, tRNA, rRNA), whereas DNA is just DNA. 22. DNA and RNA are both what types of macromolecules? Nucleic Acids! 23. What are the three types of RNA? Messenger (mRNA), Ribosomal (rRNA), and Transfer (tRNA) 24. When DNA is transcribed into RNA, does the entire chromosome get transcribed? No. Only a small portion of the chromosome, a gene, is transcribed. 25. During transcription, what is the importance of the TATA box and the terminator sequence? The TATA box signals the RNA Polymerase to come to the DNA, where to start transcription, which strand to transcribe. The terminator sequence signals to RNA Polymerase to end transcription. 26. Which enzyme is responsible for opening the DNA double helix during transcription? RNA polymerase. Does it all by himself! 27. Which enzyme is responsible for building the mRNA? RNA polymerase. Does it all by himself! 28. Are both strands of DNA transcribed during transcription? No, only the template strand is transcribed. 29. In eukaryotes, where does transcription take place? In the nucleus. (DNA never leaves the nucleus of a eukaryotic cell). 30. What are the monomer units of nucleic acids? Nucleotides 31. What type of macromolecules are DNA and RNA? Nucleic Acids 😊 32. Two men are ultimately credited with the discovering the structure of DNA. What are their names? James Watson and Francis Crick 33. What are the 2 things the ‘genetic material’ had to be able to do? 1. Copy itself perfectly 2. Act as the genetic code for all of life