Unformatted text preview:

Biology 1005 Test #3 ReviewChapters 11, 12, 13Chapter 1111.1• Be familiar with the experiment by Griffith showing that genes are made of DNA. If you can describe the experiment without notes you are probably in good shape here.o S-strain has pneumonia, R-strain doesn’to Injected heat-killed S-strain into mouse, didn’t get pneumoniao Injected R-strain into mouse, didn’t get pneumoniao Injected both at the same time, and the mouse got pneumonia b/c S-strain DNA got into R-strain cells and made pnemoniao Conclusion: you can kill cells, but not the DNA. DNA will mix with other cells11.2• You should know the structure of DNA VERY WELL. o Double helixo Backbone: sugar, phosphate, sugar, phosphate, etc.o Bases: A, G, C, T & Hydrogen bonds b/t baseso DNA is made up of nucleotides: one sugar (deoxyribose), phosphate group, base• Review figures 11.3 and 11.4. • Know the complementary base pairing of DNA.o A-T and G-C pair togethero Hydrogen bonds between the base-pairso Adenine & Guanine larger b/c they consist of two fused rings11.3• DNA encodes information not because of the number of nucleotides, but the sequence of nucleotides. 11.4• Know the basics behind DNA Replication. o DNA helicases (enzymes) pull apart two DNA strain’s at the hydrogen bondo DNA polymerase (enzymes) matches complementary nucleotides onto base strandso Two new DNA strands—parental pairs w/ daughter and winds together• You should be able to explain figure 11.6, but it wouldn’t hurt to understand figure E11-7. • The take home message is that DNA replication is semiconservative because the newly formed strands have one parental strand and one new strand.11.5• You should know all the different types of mutation that can occur during DNA replication.o Point mutation: one nucleotide is changedo Insertion: one or more pairs of nucleotides insertedo Deletion: one or more pairs of nucleotides deletedo Inversion: piece of DNA is cut out, turned around, and reinsertedo Translocation: large chunk of DNA is removed & inserted in another chromosome• Be able to explain figure 11-8Chapter 1212.1 • One gene codes for one protein• Know the difference between DNA and RNA – table 12.1o RNA: 1 strand, ribose, Uracil matches w/ Adenineo DNA: 2 strands, deoxyribose sugar, Thynine matches / Adenine, contains genes• There are three types of RNA – know their functions – figure 12.1 mRNA: carries code for protein (gene) from DNA to ribosome rRNA: combines w/ proteins to form ribosomes tRNA: carries amino acids to ribosomes • Transcription – DNA codes for RNA – table 12.2• Translation – RNA codes for a protein• Genetic code is in Codons (three bases of mRNA)• Codons code for amino acids o Codons of mRNA pair w/ Anti-codons of tRNA• Don’t need to know all the amino acids, but should recognize that multiple codons code for some amino acids, and start and stop codons begin and end translation processo Start: AUGo Stop: UAA, UGA, UAG12.2• Need to know the basics behind Transcription (DNA transcribed in RNA)1. Initiation:a. RNA polymerase finds beginning of the DNA (promoter)b. RNA polymerase binds to promoter regionsc. Begins separating DNA at the promoter region2. Elongation:a. RNA polymerase travels down template DNA strand & synthesizes single, complementary RNA (A pairs with U)b. Ribose nucleotides are added to RNA strandc. RNA drifts away, but DNA stays attached to RNA polymerase3. Termination: a. RNA continues down template strand until it reaches termination signalb. RNA polymerase releases DNAc. RNA polymerase is free to bind w/ other promoters• Know figure 12.3 VERY WELL. If you know this, then you know transcription12.3• Transcription and translation are different between prokaryotes and eukaryoteso prokaryotes both take place in the same place and time• What are introns and exons? What importance do they serve?o Exons: segments of DNA expressed in a proteino Introns: segments of DNA not expressed in a protein; hidden within a geneo After DNA is transcribed, RNA is organized so introns are cut out, and different proteins are made from different varieties of exons• Know the basics behind Translation (RNA codes for Protein)1. Initiationa. Pre-initiation complex (tRNA, proteins & small ribosomal subunits) bind to mRNA & scan for start codonb. tRNA anticodon binds w/ mRNA start codon (AUG)c. Large ribosomal subunit binds w/ small subunit & traps mRNA, and hold tRNA in first tRNA binding site2. Elongationa. Second codon of mRNA binds to second anticodon of tRNAb. Catalytic site on large subunit breaks first bond of codon & anti codonc. First/empty tRNA stain is releasedd. Ribosome moves down mRNA and second amino acid forms peptide bond w/ first amino acid3. Terminationa. Process is repeated until stop codon is reachedb. mRNA and completed peptide are releasedc. Subunits separated. Ribosomes can translate another mRNA• Know figure 12.7 VERY WELL. If you know this then you probably understand translation.• Understand complementary base pairing. You may have to derive RNA5 sequences from given DNA sequences or vice versao A goes back to T, no U’s in final RNA12.4• Know the different types of mutations, and which ones are the most problematico Pointo Deletiono Insertiono Insertiono Translocations• What could be the possible results of substitutions?o Protein unchangedo New protein has same function as old oneo New protein, new functiono Protein function is destroyed by amateur stop codon12.5• How are genes regulated in prokaryotes – operons – Understand figure 12.9 (relatively well)o DNA organized into packages called operonso Operons are genes that have similar functions, and lie close to each other, so that functionally similar proteins are synthesized at the same timeo Four parts of operon: Regulatory gene—controls timing of rate of transcription of other genes Promoter—Where RNA polymerase begins transcribing Operator—governs the access of RNA to the promoter Structural genes—encode related enzymes or other proteins• There are 5 methods of gene regulation in eukaryotes and they occur at certain times in the process of DNA to Protein. Can you describe them, and where they take place? - figure 12.101. Cells can control frequency at which an individual gene is transcribed (Transcription in Nucleous) – certain genes are needed at different times2. Same gene can be used to produce different mRNA and proteins

View Full Document

Virginia Tech BIOL 1005 - Test #3 Review

Documents in this Course
Load more
Download Test #3 Review
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...

Join to view Test #3 Review and access 3M+ class-specific study document.

We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Test #3 Review 2 2 and access 3M+ class-specific study document.


By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?