Exam 3 Chapter 16A discrete unit of hereditary information consisting of a specific nucleotide Genetic information is stored in Genes, and it is expressed in transcription and translation Single DNA strands are held together by covalent bonds and double stranded DNA is held by hydrogen bonds. Covalent bonds are stronger DNA replicates semi conservativelyExponential scales are very important for biology and all of science. Some examples are : Exponential growth PH Length scales( on volumes) Centrifuges work by spinning and separating materials (molecules) by density Primers are nucleic acids used to start a DNA synthesis Repairs: Nucleotide excision repair: fixes damaged DNA Mismatch repair: fixed mistakes in newly synthesized DNA, this mechanism is able to distinguish the new DNA from the old DNA because of methyl locationChromosomes can be more or less condensed, example: More condensed are mitotic chromosome Less condensed are chromatin, chromatins are also highly organized in the nucleus“A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, insome viruses).”a.chromasomeb.chromatinc.genomed.genee.none of the aboveIf one strand of a DNA molecule has the sequence of bases 5'-GATTACA-3', the other complementary strand would have the sequencea.5'-CTAATGT-3'.b.5'-CUAAUGA-3'.c.5'-ACATTAG-3'.d.5'-TGTAATC-3'.e.3'-CTAAGTG-5'A group of cells in a laboratory experiment is known to go through one complete cell cycle every24 hours (one day). If a scientist has 1000 cells, how long would he or she expect to wait to have 4000 cells? a.12 hours (half a day) b.24 hours (one day) c.48 hours (two days) d.72 hours (three days) e.96 hours (four days) An enzyme that catalyzes the elongation of new DNA (for example, at a replication fork) by the addition of nucleotides to the 3Œ end of an existing chain.h a.DNA synthaseb.DNA nucleasec.DNA ligased.DNA polymerasee.none of the aboveWhich of the following is true of DNA during interphase?a.It is in the form of highly condensed chromosomes; it is called heterochromatin.b.It is in the form of highly condensed chromosomes and is unavailable for gene expression.c.It exists as chromatin; it is completely uncoiled and loose.d.It exists as chromatin and is unavailable for gene expression.e.It exists as chromatin and is less condensed than mitotic chromosomesThe two strands in a double stranded DNA molecule are held together by _______________.a.hydrogen bondsb.covalent bondsc.peptide bondsd.ionic bondse.Van der Waals interactions1. DNA replication: The process by which a DNA molecule is copied; also called DNA synthesis.Replication: The leading strand is synthesized forwards the replication fork The lagging strand is synthesized away from the replication fork2. Transformation: (1) The conversion of a normal animal cell to a cancerous cell. (2) A change in genotype and phenotype due to the assimilation of external DNA by a cell. When the external DNA is from a member of a different species, transformation results in horizontal gene transfer.3. Bacteriophage: A virus that infects bacteria.4. Virus: An infectious particle incapable of replicating outside of a cell, consisting of an RNA or DNA genome surrounded by a protein coat (capsid) and, for some viruses, a membranous envelope.5. Double helix: The form of native DNA, referring to its two adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape.6. Antiparallel: Referring to the arrangement of the sugar-phosphate backbones in a DNA double helix (they run in opposite 5 → 3 directions).′ ′7. Semiconservative model: Type of DNA replication in which the replicated double helix consists of one old strand, derived from the parental molecule, and one newly made strand.8. Origin of replication: Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.9. Replication fork: A Y-shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are being synthesized.10. Primer: A short stretch of RNA with a free 3 end, bound by complementary base pairing to the ′template strand and elongated with DNA nucleotides during DNA replication.11. DNA polymerase: An enzyme that catalyzes the elongation of new DNA (for example, at a replication fork) by the addition of nucleotides to the 3 end of an existing chain.′12. Okazaki fragments: A short segment of DNA synthesized away from the replication fork on a template strand during DNA replication. Many such segments are joined together to make up the lagging strand of newly synthesized DNA.13. DNA ligase: A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3 ′end of one DNA fragment (such as an Okazaki fragment) to the 5 end of another DNA fragment (such as ′a growing DNA chain).DNA ligase connects two DNA strands covalently14. Mismatch repair: The cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides.15. Nuclease: An enzyme that cuts DNA or RNA, either removing one or a few bases or hydrolyzing the DNA or RNA completely into its component nucleotides.16. Telomere: The tandemly repetitive DNA at the end of a eukaryotic chromosome's DNA molecule.Telemers are DNA sequence at the end of chromosomes that get shorter each time the chromosome is replicated17. Nucleoid: A non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated.18. Chromatin: The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cellis not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope.19. Heterochromatin: Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed.20. Euchromatin: The less condensed form of eukaryotic chromatin that is available for transcription.Chapter 17All of life more or less uses the same genetiv codeBecause of that, we can transfer genes beteween orrganisms by genetic engineering RNA is first synthesized as “primary transcript” which can be processed to form mRNA “Exons” are the parts of a transcript that are processed Gene expression is a process by which the DNA sequence of a gene is used as a template for the synthesis of a protein sequence.Transfer RNA determines the genetic code Translation:-
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