Bundle 5 Test Review

Transcription

1 Bundle 5 Test Review DNA vs. RNA DNA Replication Gene Mutations- Protein Synthesis 1. Label the different components and complete the complimentary base pairing. What is this molecule called? _Nucleic Acid Pentose Sugar Hydrogen Bond Phosphate Group Nitrogenous Bases Nucleotide 2. Shortly describe what happens at each step of DNA replication (SYNTHESIS of DNA be sure to include the enzymes). 1. Helicase unwinds and unzips DNA. 2. Primase primes the DNA for replication. 3. DNA polymerase adds nucleotides. 4. Ligase reforms the hydrogen bonds between nucleotides. 5. The two strands are proofread. Result 2 strands of DNA identical to the original. Each strand contains one original strand and one new strand (semiconservative replication) 3. Why the DNA replication is called semiconservative? _Each strand of DNA has one original side and one new side.

2 4. What roles do helicase, DNA polymerase and ligase play in DNA replication? Helicase: _Unwinds & unzips DNA 5. Fill in the table to compare and contrast DNA and RNA. DNA polymerase: _adds nucleotides It can only add nucleotides in one direction (circle: 3 to 5 or 5 to 3 ) Ligase: Reforms hydrogen bonds between nucleotides Feature DNA RNA Name of molecule Deoxyribonucleic Acid Ribonucleic Acid Number of strands in molecule Double (2) stranded Single (1) stranded Type of sugar in nucleotide Deoxyribose Ribose Nitrogenous bases Adenine, Cytosine, Guanine and Thymine Adenine, Cytosine, Guanine, and Uracil Monomer Nucleotide Nucleotide Nucleotide components Phosphate Group, Deoxyribose, and a Nitrogenous Base Phosphate Group, Ribose, and a Nitrogenous Base Function Provides genetic code for organism Transports and translates genetic code for organism Shape Double Helix Single Stranded Location in cell Nucleus Nucleus and Cytoplasm 6. Fill in the table to indicate the differences between mrna, trna, and rrna. For numbers #3-#5 check the appropriate box in the table below. Types of RNA mrna rrna trna 1. Stand for messenger ribosomal transfer 2. Function Carries genetic information (instructions) from the nucleus to the ribosome, rrna RIBOSOME Reads message & assembles AA into proteins (makes proteins) Transfers an amino acid to the growing protein chain on a ribosome. 3. Codon 4. Anticodon 5. Cloverleaf shape 7. What is a mutation? A mistake that is not repaired within the genetic code 8. What is a gene mutation? A permanent alteration in a DNA sequence that makes up a gene 9. What are the types of gene mutations? Point Mutations and Chromosomal Mutations Give an example of each. Point: Substitution (silent, missense, nonsense), Frameshift, Etc. Chromosomal: Translocation, Inversion. 10. Why are the frameshift mutations the most harmful? They alter the sequence of bases at the mutation and after the mutation. This changes the amino acid sequence and the resulting protein. 11. What causes mutations and why are they important? A mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism. Therefore they increase the frequency of mutations.

3 12. What is the Central Dogma of biology? The process of expressing the information expressed in DNA through the production of mrna (transcription) and the synthesis of proteins (translation). DNA mrna Protein Transcription Translation 13. How do we move information from DNA to proteins? Fill in the missing information. Process: _Transcription Location: _Nucleus Process: _Transcription_ Location: _Cytoplasm Molecule: _DNA Molecule: _mrna Molecule: _Protein 14. Place the correct terms into the illustration boxes. Terms to use: Amino Acid, Codon, Anticodon, DNA, Mature mrna, mrna, Nuclear Envelope, Protein, Ribosome (rrna), trna, Transport to cytoplasm, Transcription, Translation, Cell membrane.

4 Nuclear Envelope Amino Acid Protein Translation Anticodon mrna Codon Ribsome (rrna) 15. Where does transcription take place in the cell? _Nucleus 16. Where does translation take place in the cell? _In the cytoplasm at a ribsome 17. Where in the cell does mrna travel to? _From the nucleus into the cytoplasm and to a ribsome 18. What is a codon and anticodon? Codon every 3 bases that specify an amino acid Anticodon - 3 complimentary bases bind to the mrna codon.

5 19. Look at the following molecule of DNA. Transcribe DNA into mrna strand and translate it into a protein. Also include the processes that are taking place at each of these steps. Process: _Transcription A G G C G C G U C U C G A U C Process: _Translation U C C G C G C A G A G C U A G Arginine Arginine Valine Serine Isoleucine **NOTE: trna looks just like the original DNA with all the thymine removed and replaced with Urasil. Amino Acids are found using the mrna codon not the trna anticodon. 20. Use the diagram below explain the difference between an exon and intron? Which one is used? _Exon Exon - _Genetic sequences used to code for a protein Intron - _Extra genetic sequences (noncoding) that are removed Because they are not needed in protein synthesis 21. How is prokaryotic gene regulation (lac operon) different from eukaryotic gene regulation? Prokaryotic: don't have cell specific gene expression, have to respond quickly to changes in their environment, organized in operons and transcribed by a single mrna Eukaryotic: have other regulatory needs so they have a different set of regulatory controls, are NOT regulated by operons, each structural gene has its own promoter and is transcribed independently. Only genes that are needed for the cell to perform its function are turned on. Identify the processes in the pictures. Process: _Translation Process: _Transcription Process: _DNA Replication 22. STUDY YOUR CELL TRANSPORT MOST MISSED CONCEPTS!