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| 8069707820 | Frederick Griffith- 1928: | DNA can transform bacteria Experiment: Studied two strains of Streptococcus pneumoniae bacteria with different appearances. S (smooth)= caused disease R (rough)= no disease Griffith injected mice with these two strains S cells- mouse died R cells- mouse didn't get sick Heat killed S cells- mouse healthy Mixture of heat killed S cells and living R cells- mouse died Conclusion- some chemical component (DNA) of the dead pathogenic cells caused the living cells to become pathogenic. Living R bacteria took up something from dead S bacteria (DNA) | 0 | |
| 8069707821 | Hershey & Chase- 1952: | Viral DNA can program cells Viruses can infect bacteria. These phages (T2) attach to plasma membrane and inject only genetic material Experiment: Radioactive elements to trace the fates of protein (using S*) and DNA (using P*) of T2 phages that infected bacterial cells. Did DNA or protein enter cells and reprogram them to make more phages Conclusion- phage DNA entered bacterial cells bugt phage protein did not. DNA is genetic material | 1 | |
| 8069709751 | Chargaff's Rule- 1950: | Base composition varies between species but the % of #A=#T and #C=#G Experiment: Analyzed base composition of DNA from a number of different organisms. Conclusion: The base composition of DNA varies from one species to another but the amount of A = amount of T and amount of C= amount of G. Basis of these rules remained unexplained until the discovery of the double helix | 2 | |
| 8069709752 | Rosalind Franklin- 1952: | X-ray diffraction Sugar-phosphate backbone | 3 | |
| 8069712585 | Watson & Crick- 1953: | Base-pairing A/T; C/G Double helix | 4 | |
| 8069755754 | Race to solve the structure of DNA | Experiment: X-ray diffraction, understanding chemistry and molecular modeling. Conclusion: DNA is made of a double helix with a sugar-phosphate backbone and nitrogenous bases (A-T and C-G) hydrogen bonded in the middle. | 5 | |
| 8069770285 | Structure of DNA strand | Double helix- two anti-parallel sugar-phosphate backbones held together by hydrogen bonds between the nitrogenous bases, which are paired in the interior. Purines (AG) always pair with pyrimidines (CT) to result in a uniform diameter A and T held together by 2 hydrogen bonds C and G held together by 3 hydrogen bonds |  | 6 |
| 8069778589 | DNA polymerase catalyzes the addition of a _______ to the _____' end of a growing DNA strand with the release of two __________ | DNA polymerase catalyzes the addition of a nucleotide triphosphate to the 3' end of a growing DNA strand with the release of two inorganic phosphates | 7 | |
| 8069782790 | Meselson and Stahl- semiconservative replication | Experiment: Bacteria were grown for several generations in media containing a heavy isotope of nitrogen (N15). They then transferred the bacteria to media with only N14, a lighter isotope. Samples were taken after DNA had replicated and DNA of different densities were separated. Semi-conservative=50/50 mix One round replication= all DNA will have one N15 strand and one N14 strand After two rounds replication= half DNA will be half/half and half DNA will be all N14 |  | 8 |
| 8069795411 | Deoxyribose sugar carbons: Nucleotides can only be added on the __' end. Replication can only occur __' to ___' | Nucleotides can only be added on the 3' end. Replication can only occur 5' to 3' | 9 | |
| 8069801770 | Chromosome = DNA + ________ When DNA is not dividing, it is ________ Eukaryotic chromosomes are _______ DNA molecules associated with histone proteins. | Chromosome = DNA + histone proteins When DNA is not dividing, it is wrapped around proteins called histones (wraps around 8 histones). Eukaryotic chromosomes are linear DNA molecules associated with histone proteins. | 10 | |
| 8069838631 | The replication of a DNA molecule begins at sites called _________ with specific sequences of __________. DNA strands separate to create _______and _________. Circular bacterial chromosomes have ____origins of replication Eukaryotic linear chromosomes have _____ origins of replication | The replication of a DNA molecule begins at sites called origin of replication with specific sequences of nucleotides. DNA strands separate to create replication bubbles and forks. Circular bacterial chromosomes have one origin of replication Eukaryotic linear chromosomes have many origins of replication |  | 11 |
| 8069848282 | Primase | Synthesizes RNA primers, using the parental DNA as a template |  | 12 |
| 8069848283 | RNA Primer | Joins sugar-phosphate backbone of DNA | | 13 |
| 8191993989 | Single-strand DNA binding proteins | keeps DNA strands apart |  | 14 |
| 8069850597 | Helicase | Opens DNA, unwinds and separates the parental DNA strands |  | 15 |
| 8069850598 | Topoisomerase | Breaks, swivels, and rejoins the parental strand ahead of the replication fork- prevents DNA bunching before replication fork |  | 16 |
| 8069853696 | DNA Polymerase | Catalyzes the synthesis of new DNA by adding nucleotides to a preexisting chain 5'3' (TAC, ATC) |  | 17 |
| 8191801309 | Okazaki fragments | Short, newly synthesized DNA fragments that are formed on the lagging template strand during DNA replication. They are complementary to the lagging template strand, together forming short double-stranded DNA sections. |  | 18 |
| 8069879211 | Rules of DNA Replication: 1) DNA is always read ___' to ___' 2) DNA is synthesized from ___' to ___' 3) Helicase ________ 4) DNA polymerase ________ 5) Primase ________ 6) DNA ligase acts like _______ | 1) DNA is always read 3' to 5' 2) DNA is synthesized from 5' to 3' 3) Helicase opens up the DNA 4) DNA polymerase synthesized the DNA (builds DNA) 5) Primase to start synthesis of both strands 6) DNA ligase acts like DNA super glue | 19 | |
| 8069892416 | Errors during DNA replication.... Only occur ________ nucleotides and During synthesis ________ nucleotides | Only occur 1 in 10 billion (10^10) nucleotides During synthesis 1 in 10^5 nucleotides | 20 | |
| 8069897082 | Repair Mechanism: Mismatch Repair= | DNA polymerase proofreading fixes any mismatched ones | 21 | |
| 8069897083 | Repair Mechanism: Nucleotide Excision Repair | DNA cut out, replaced, and glued back together |  | 22 |
| 8069897084 | Telomeres | Special repetitive nucleotide sequences at the ends of eukaryotic chromosomes. Protect genes from being eroded during successive rounds of replication. | 23 | |
| 8069931478 | Telomerase | Catalyzes the lengthening of telomeres to restore their original length |  | 24 |
| 8069960221 | Why do we need cell division? | 1) To create a new organism (prokaryotic and unicellular cells) 2) Reproduction 3) Growth and development 4) Tissue renewal and repair | 25 | |
| 8069966060 | Gametes | -reproductive cells -have 23 chromosomes= half as many as parent) -Haploid (n) -In: Meiosis | 26 | |
| 8069966061 | Genome | A cell's entire collection of DNA | 27 | |
| 8069969316 | Somatic Cells | -all body cells except reproductive cells -have 23 pairs of chromosomes -Diploid (2n) -In: Mitosis | 28 | |
| 8069966062 | Chromatin | The complex of DNA and proteins that make up eukaryotic chromosomes | 29 | |
| 8069971825 | Chromosome | Required for genetic inheritance, made of DNA and protein A very long DNA molecule associated with proteins |  | 30 |
| 8070052459 | Cell Division: Mitosis | (Somatic) Nuclear division of a cell after DNA replication resulting in 2 identical genomes/diploid daughter cells (each with 23 pairs of chromosomes) (5 stages) |  | 31 |
| 8070055297 | Cell Division: Meiosis | (Sex cells, Gametes) Cells replicated DNA and divide twice into 4 gametes (half genome cell) |  | 32 |
| 8070000331 | Sister Chromatids | Replicated chromosomes (attached by proteins at the centromere) |  | 33 |
| 8070114016 | Interphase | -Cell growth and DNA replication -(90% of the cell cycle) -G1 phase= prepare for DNA replication -S= DNA synthesis/replication- DNA polymerase -G2= prepare for mitosis -Replicate then separate! -(no individual chromosomes visible) -(Nuclear envelope still well defined) |  | 34 |
| 8070136703 | Mitotic M phase | Mitosis followed by Cytokinesis -Prophase -Prometaphase -Metaphase -Anaphase -Telophase |  | 35 |
| 8070169072 | Prophase | -Chromatin condenses into densely packed visible chromosomes -Mitotic spindle begins to form from centrosomes -Centrosomes start moving into position at opposite ends of the cell -Nucleolus disappears |  | 36 |
| 8070169073 | Prometaphase | -Nuclear envelope breaks down -Spindles start to invade nuclear space -Spindles attach to kinetochore of duplicated chromosomes -Kinetochore: proteins located at the centromere of each chromosome |  | 37 |
| 8070171411 | Metaphase | -Centrosomes are now at opposite ends of the cell -Spindle fibers push and pull until all chromosomes are lined up at the metaphase plate -Metaphase plate: the plane midway between the two poles of the cell |  | 38 |
| 8070171412 | Anaphase | -Duplicated chromosomes are pulled apart -Sister chromatids are pulled apart -Each chromatid is now back to an unduplicated chromosome -Each pole should now have identical and complete genomes |  | 39 |
| 8070171413 | Telophase | -Spindle fibers break down -Nuclear envelope reforms -Chromosomes become less tightly condensed (coiled) -Nucleolus reforms -THE END OF MITOSIS |  | 40 |
| 8070205608 | Cytokinesis | -After mitosis/meiosis -Cell division of cytoplasm -2 daughter cells form -CELL DIVISION ENDS |  | 41 |
| 8070205609 | Cytokinesis: Animal | Cleavage furrow |  | 42 |
| 8070208178 | Cytokinesis: Plant | Cell plate |  | 43 |
| 8070244657 | Mitotic Spindles | -Aster microtubules -Centrosome with centrioles -Kinetochore microtubules (proteins built on centromere= bind MTs) -Telomeres= end of two tips |  | 44 |
| 8070268486 | How do spindles "pull" apart sister chromatids? | Microtubules are shrinking and disemble at kinetochore causing the sisters to pull apart | 45 | |
| 8070275130 | Cell Cycle Control: Different cell types have different cell cycle control | Skin- divide frequently Liver- divide only when necessary Neurons- don't divide after maturity | 46 | |
| 8070275132 | Cell Cycle Control: Internal Cues | -Molecular control systems -Cell cycle checkpoints -Growth factors | 47 | |
| 8070275133 | Cell Cycle Control: External Cues | -Anchorage dependence -Density-dependent inhibition | 48 | |
| 8070291416 | Normal cells vs Cancer cells | Normal cells: When there is an issue, normal cells stop the cell cycle and either repair the DNA or if they can't they kill themselves (apoptosis) Cancer cells: DNA damage-->doesn't stop at checkpoints-->doesn't stop growing/dividing No density dependent inhibition and weakened adhesion Cancer cells divide rapidly and form into a tumor mass | 49 | |
| 8070304090 | G1 Checkpoint | is the genome & environment okay for DNA replication? -If no, stop, wait and repair. -If so, go to S phase | 50 | |
| 8070304091 | G2 Checkpoint | was the DNA correctly replicated for mitosis? -If no, stop! -If so, go to mitosis | 51 | |
| 8070307265 | M Checkpoint | are chromosomes ready for separation? -If no, stop! -If ok, go to anaphase | 52 | |
| 8070307267 | If cell is stopped at a checkpoint it can do 3 things.... | 1) Stop, wait and try to repair 2) Exit cell cycle, entering G0 phase 3) Induce apoptosis (suicide) | 53 | |
| 8070320270 | Regulatory Proteins | = run cell cycle -Protein(s) present in mitotic cells that could induce mitosis in other cell types MPF, Cyclins, Cdk | 54 | |
| 8070335589 | MPF | MPF-Maturation(Mitosis) Promoting Factor= Cyclin + Cdk (activity) that triggers mitosis |  | 55 |
| 8070338436 | Cyclins | -Proteins that activate kinases to control the cell cycle -Accumulates during interphase--->binds to cyclin dependent kinases (Cdks) | | 56 |
| 8070340695 | Cdk | Cyclin-dependent kinases- kinases that control cell cycle (kinase= adds phosphate group/phosphorylation) | | 57 |
| 8070360717 | Cdk + cyclin= | -activity drives mitosiscyclin is then degraded after mitosis = active kinase which activates cells | 58 | |
| 8070380320 | Oncogenes | Overactive positive cell cycle regulators (presence-->cancer). If activated--->drive cell cycle ex=Ras gene: Signaling protein that stimulates growth and cell division. Mutations cause hyperactive Ras & excessive cell division 20-25% of all humans tumors are Ras mutations Normal ras + growth factor--->cell division Oncogenic ras + no growth factor--->cell division Cancer= ras is always on--->cell division | 59 | |
| 8070406607 | Tumor Suppressor Genes and example | Inactive negative cell cycle regulators (absence--->cancer) Normally stops cell cycle, if motivated--->drives cell cycle ex=p53 gene Normal p53= Stops cells at G1 checkpoint if DNA is damaged & needs repair. If can't repair p53 induces apoptosis. Cancer p53= allows damaged DNA to go through replication/cell division | 60 | |
| 8150354292 | Asexual Reproduction | Generation of offspring from a single parent that occurs without fusion of gametes. Offspring are identical to parent Binary Fission- Bacteria reproduction |  | 61 |
| 8150364644 | Sexual Reproduction | -Reproduction in which two parents give rise to offspring that have unique combination of genes inherited from both parents via gametes (sex cells) ex=Haploid + Haploid (these are gametes)(have 23 chromosomes) = Fertilization (Diploid/ Zygote-fertilized egg) =homo chromosomes 3 pairs (II, ii, II) -One round of DNA replication followed by two rounds of cell division to produce haploid gametes -Duplicate in S phaseseparate 1(makes homologous chromosomes)separate 2(makes sister chromatids) | 62 | |
| 8150380419 | The human genome: ____ pairs of chromosomes: -Chromosomes pairs 1-22= -________ -Chromosomes pair 23= _______ Homologous Chromosomes: -______ Chromosomes -1 from ___ and 1 from ____ | 23 pairs of chromosomes: -Chromosomes pairs 1-22= Autosomes -Chromosomes pair 23= Sex chromosomes Homologous Chromosomes: -Paired Chromosomes -1 from mom and 1 from dad | 63 | |
| 8150396563 | Karyotype | =A display of all condensed chromosome pairs of a cell arranged by size and shape -Can be used to screen for defective chromosomes or abnormal numbers of chromosomes associated with genetic diseases like Down Syndrome -Karyotypes must be done on Mitotic cells. Why? =because that is the only phase where they are condensed | 64 | |
| 8150405462 | Meiosis | Only in germ cells (diploid)sperm or egg (haploid) DNA replicationMeiosis IMeiosis II 1.DNA replication 2.Cell Division (meiosis I) 3.Cell Division (meiosis II) =4 different gametes | 65 | |
| 8150449320 | Mitosis | 1.DNA replication (Replicate) 2.Cell Division (Separate) =2 identical daughter cells | 66 | |
| 8150463740 | Meiosis I vs Meiosis II | I= separates homologous chromosomes II= separates sister chromatids | 67 | |
| 8150471958 | Three ways of increasing genetic diversity in meiosis | 1) Crossing Over=produces gametes differing from either parent 2) Independent Assortment=Random orientation of pairs of homologous chromosomes at metaphase I of meiosis I 3) Random Fertilization=Fusion of one random egg and one random sperm during fertilization | 68 | |
| 8150477347 | Prophase I- ____ occurs | Crossing over occurs= a genetic rearrangement between non sister chromatids in prophase I of meiosis I involving the exchange of corresponding segments of DNA molecules |  | 69 |
| 8150484706 | Metaphase I- _____ occurs | Independent assortment= Each pair of homologous chromosomes may orient with either its maternal or paternal homolog closer to a given pole during metaphase I of meiosis I |  | 70 |
| 8150493401 | Random Fertilization | A zygote is formed by the random union of gametes. In humans each gamete represents ~1 in 8.4 million possible chromosomal combinations from independent assortment. Random fertilization produces a zygotes with any of about 70 trillion diploid combinations! You are unique! | 71 | |
| 8150494940 | Fertilization | Upon fertilization the egg undergoes dramatic changes to prevent polyspermy | 72 | |
| 8150497575 | Gametogenesis | =making gametes -Spermatogenesis --> 4 haploid sperm Oogenesis --> 1 haploid egg |  | 73 |
| 8160283223 | DNA= _____ stranded, ______ sugar (_____ carbon and _______ on last), ATCG RNA= ______ stranded, _______ sugar, AUCG | DNA= double stranded, deoxyribose sugar (5 carbon and phosphate on fifth), ATCG RNA= single stranded, ribose sugar, AUCG | 74 | |
| 8160327189 | 3 kinds of RNA | mRNA (messenger)= specifies primary protein structure rRNA (ribosomal)= together with protein makes the ribosome tRNA(transfer)= recognize mRNA codon and brings in amino acid for translation | 75 | |
| 8160405065 | The central dogma: Gene= | functional unit of DNA that provides instructions for a functional product- DNA that encodes for protein | 76 | |
| 8160412118 | DNA to RNA | Process: transcription Purpose: RNA synthesis Location: nucleus Machine: RNA polymerase | 77 | |
| 8160412119 | RNA to Protein | Process: translation Purpose: protein synthesis Location: cytoplasm Machine: Ribosome | 78 | |
| 8160435289 | Transcription | One strand of DNA acts as a template for the synthesis of a complementary RNA strand by RNA polymerase RNA polymerase uses template strand | 79 | |
| 8160440021 | Translation | The nucleotide sequence of mRNA is translated into the amino acid sequence of a polypeptide protein by ribosomes codon= 3 nucleotides that encode for an amino acid (AUG, AUC, UCG, UAA) | 80 | |
| 8160446726 | The Triplet Code | Codon on mRNA pairs with anticodon on tRNA (which brings in appropriate amino acid) -Ribosome "reads" mRNA codon and "translates" that into appropriate tRNA anticodon and amino acid | 81 | |
| 8160510163 | Transcription in more detail | -In the nucleus -RNA polymerase opens DNA to expose template strand of DNA -RNA polymerase binds promoter region start transcription (DNA RNA) -DNA template strand is "read" and mRNA is synthesized by adding complementary RNA nucleotides -RNA polymerase stops transcribing at the terminator region -mRNA must be processed before leaving the nucleus (introns removed) | 82 | |
| 8173155713 | Three phases of transcription | Initiation- RNA polymerase binds promoter, unwinds DNA, starts making mRNA Elongation- RNA polymerase unwinds DNA and continues to add complementary nucleotides in 5' 3' direction Termination- termination signal indicates "stop" and mRNA transcript is released [UAA, UAG, UGA] codons STOP | 83 | |
| 8173158562 | Promoter | TATA box- sequence on DNA Transcription factor binding RNA polymerase recruitment | 84 | |
| 8173163251 | Elongation | RNA polymerase adds nucleotides 5' 3' direction | 85 | |
| 8173233735 | mRNA processing (only in eukaryotes) | mRNA is long 5' cap start codon [AUG] stop codon [UAA, UAG, UGA] 3' poly A tail intron: get removed exon: are expressed and remain RNA processing > splice out introns | 86 | |
| 8173238182 | mRNA Processing | Spliceosome= Large molecular machine in the nucleus of eukaryotic cells that removes introns from pre-mRNA. INtrons IN the trash and EXons are EXpressed! | 87 | |
| 8173240535 | Ribosomes and Translation | 1 small ribosomal subunit + 1 large ribosomal subunit Groove for mRNA reading Three tRNA binding sites= E-Exit, P-binding, A-entry | 88 | |
| 8173244111 | Three phases of translation | Initiation- ribosome subunits assemble around mRNA and the first tRNA added is the "start" codon [reads AUG puts in UAC attached to Methionine] Elongation- ribosome reads mRNA codons and adds appropriate tRNA anticodon and corresponding amino acid. Amino acid chain elongates. Termination- ribosome reads mRNA stop codon (UAA, UAG, UGA), the finished polypeptide chain is released, and the ribosome disassembles | 89 | |
| 8173248874 | Translation Initiation | Small ribosomal subunit with first tRNA [UAC anticodon + Met] binds mRNA This complex scans mRNA to find matching AUG start codon Large ribosomal subunit binds to form Translation Initiation Complex | 90 | |
| 8173255531 | Translation Elongation | tRNA bound to codon Next tRNA binds in A site New peptide bond formed Growing amino acids now attatched in A site Ribosome moves forward to read next codon on mRNA. "Empty" tRNA exits. | 91 | |
| 8173259562 | Translation Termination | Ribosome reads an mRNA stop codon (UAA, UAG, UGA) "Release factor" protein binds in the A site instead of a tRNA The last tRNA is released from the ribosome, ribosome disassembles, and new polypeptide is released | 92 | |
| 8193465066 | Eukaryotic vs Prokaryotic Translation | Eukaryotic- Transcription in nucleus mRNA processed Translation in cytosol Prokaryotes- No nucleus Transcription and translation are combined | 93 | |
| 8193478719 | Point Mutations in DNA | =Single nucleotide change | 94 | |
| 8193481593 | Silent mutation= Nonsense mutation= Missense mutation= Frameshift mutation= | Silent mutation= no effect on protein Nonsense mutation= leads to premature stop---->incomplete protein Missense mutation= leads to faulty protein Frameshift mutation= caused by insertion and/or deletion of a number of nucleotides not divisible by three |  | 95 |
