DNA Structure and Replication, and Virus Structure and Replication Test Review

Transcription

1 DNA Structure and Replication, and Virus Structure and Replication Test Review What does DNA stand for? Deoxyribonucleic Acid DNA is what type of macromolecule? DNA is a nucleic acid The building blocks (monomers) of DNA are called what, draw one and label all the parts? The building blocks (monomers) of DNA are called nucleotides Describe the double helix shape of a DNA molecule (what does it look like?) Who discovered this shape? DNA is shaped like a twisted ladder. The discovery of this structure is credited to James Watson and Francis Crick. Where is DNA found in eukaryotic cells? DNA is found primarily in the nucleus of eukaryotic cells. There is some DNA located in the mitochondria. What is the sugar found in DNA? Deoxyribose What makes up the backbone of a DNA molecule? The backbone, or sides, of a DNA molecule are made of alternating sugar and phosphate molecules.

2 Is the end of a DNA strand that holds a phosphate group called the 5 end or the 3 end? The end of DNA that contains a phosphate group is called the 5 end. What are the four nitrogen bases found in DNA? Adenine, Thymine Cytosine, Guanine What base pairs match up in DNA? Adenine Thymine Cytosine - Guanine Write the complimentary DNA strand to: TACCGAATACCTAGC ATGGCTTATGGATCG What is DNA replication? DNA replication is the process in which DNA copies itself to prepare for cell division. What enzyme is responsible for breaking the hydrogen bonds that hold together the base pairs during replication? (also called unzipping the DNA strand) The enzyme helicase breaks the hydrogen bonds between nitrogen base pairs during DNA replication. What enzyme is responsible for proofreading the daughter DNA stand to ensure that the correct base pairs are matched up correctly? (or zipping up the daughter strands) DNA polymerase is responsible for adding new nucleotides to the daughter strand during DNA replication.

3 In the diagram below label the following: Parent strands label the 5 and 3 ends of both parent strands); Daughter strands; DNA Polymerase; Helicase; Leading strand; Lagging strand ;Okazaki fragment What molecules make up proteins? Amino Acids make up proteins. What does RNA stand for? Ribonucleic Acid List 3 ways in which RNA is different from DNA 1. RNA is single stranded 2. RNA has the sugar ribose instead of deoxyribose 3. RNA contains the base Uracil in place of Thymine What are the 3 types of RNA, where are they found, and what is the function of each?

4 mrna is created in the nucleus during transcription; it s job is to carry the genetic code (message) from the DNA to the ribosome trna is found primarily in the cytoplasm; it s job is to carry the amino acids to the ribosome rrna makes up the ribosome What are the stages of protein synthesis? 1. Transcription 2. RNA Processing 3. Translation Where does transcription take place? Transcription takes place in the nucleus of the cell. What enzyme aids in the process of transcription? RNA polymerase aids the process of transcription by unzipping the DNA strand at the gene to be copied and building and proofreading the mrna strand. What type of RNA is created during transcription? mrna is created during transcription. What is a codon? A codon is 3 consecutive bases on an mrna strand that codes for a specific amino acid. Where does the message that is coded on the RNA during transcription come from? The genetic message coded on mrna during transcription comes from the DNA in the nucleus. In what part of the cell does translation take place? Translation takes place in the cytoplasm (ribosome) of the cell. What type of RNA makes up the ribosome? rrna makes up the ribosome. Where is trna found in the cell?

5 trna is primarily found in the cytoplasm of the cell. What does trna carry to the ribosome? trna carries amino acids to the ribosome. What are the 2 ends of a trna molecule? A trna molecule has an amino acid end and an anticodon end. What is an anticodon?. An anticodon is 3 consecutive bases found on a trna molecule that will bind to its complimentary mrna codon. Use the following DNA strand to find the mrna, trna, and amino acids: DNA: mrna: T A C G T T A T G A T A C T T A C T A U G C A A U A C U A U G A A U G A amino acids: start-glutamine-tyrosine-tyrosine-glutamic acid-stop What change in DNA or RNA causes a point mutation? A substitution in one base pair will cause a point mutation. Will a point mutation effect/change any amino acid after the mutation? No, a point mutation will only change the one amino acid coded where the mutation happens. How will a point mutation change the protein being made? It will possibly change one amino acid. What can cause an insertion or deletion mutation? An insertion mutation is caused when 1 or more DNA triplets (or mrna codon) are added to a gene. A deletion mutation is caused when 1 or more DNA triplets (or mrna codon) are deleted from a gene.

6 How will an insertion or deletion mutation change the protein being made? An insertion mutation causes 1 or more amino acids to be added to a protein. All the other amino acids will stay the same. A deletion mutation will cause 1 or more amino acids to be deleted from a protein, all the other amino acids will remain the same. List 2 changes in DNA or RNA that can cause a frameshift mutation. The deletion or addition of 1 or more nitrogen bases in a section of DNA will cause a frameshift mutation. Will a frameshift mutation cause any changes to the amino acids after the mutation? Yes, a frameshift mutation will change every amino acid that is coded for after the mutation. How will a frameshift mutation change the protein being made? The polypeptide chain will be completely different therefore it will not make the protein that was supposed to be made.