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23 Cards in this Set
- Front
- Back
DNA
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deoxyribonucleic acid,
hereditary material |
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Gene
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segment of DNA that codes for a functional product
Usually protein sometimes RNA |
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Chromosome
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cellular structure made up of genes linked together
complexed with protein circular in bacteria linear in eukaryotes |
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RNA
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ribonucleic acid,
compounds involved in protein synthesis |
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Transcription
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DNA to RNA
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Translation
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RNA to Proteins
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Mutation
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Chemical Change in DNA
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Genotype
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genetic constitution of the cell
genetic potential- DNA in molecular terms genone- entire collection of genes of organism |
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Genone numbers for humans & bacteria
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Humans- approx 30,000 genes
Bacteria- approx 2,000 genes |
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Phenotype & what it includes
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expressed properties of cell
Includes morphology, metabolism, & pathogenicity In molecular terms-- entire collection of proteins (proteome) |
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# of proteins in humans and bacteria
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Humans- 100,000's
Bacteria- 2,000 |
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DNA structure
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described in paper published by Watson & Crick in1953 (won Nobel Prize along with Wilkins)
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DNA molecule
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double helix- 2 spirals of polymers of nucleotides
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Building Blocks of Nucleotides
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i. phosphate group
ii. pentose (5-carbon) sugar (deoxyribose) iii. nitrogenous base (4 kinds in DNA) |
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Nitrogenous bases (4 kinds in DNA)
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Adenine A
Guanine G Cytosine C Thymine T |
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How are nucleotides named?
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named according to their base
example: thymine nucleotide or thymidine |
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Watson / Crick model
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DNA molecule consists of 2 antiparallel strands OP (Fig 8.4)
(going in opposite directions) with cross bars i. strands are twisted around each other like twisted ladder ii. = double helix uprights of so-called ladder = “backbone” of alternating phosphate groups and deoxyribose sugar portion of nucleotides OP (Fig 8.4) c. “rungs” of ladder contain nitrogenous bases in pairs joined by weak hydrogen bonds OP (Fig 8.3) i. A pairs with T; G pairs with C ii. one strand is complementary to the other like lock & key d. evidence for Watson & Crick model i. Chargaff’s Rule ii. Franklin & Wilkin’s X-ray data (“Dark Lady of DNA Brenda Maddox) (analogy to the diffracted image produced via crystal chandelier) iii. (Frederich) Meissner: DNA content of all somatic cells of same species is =; DNA content of sex cells of that species is 1/2 |
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Cellular RNA
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Second principle kind of nucleic acid
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Cellular RNA Differs from DNA in what ways
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a. RNA always is single-stranded
b. pentose sugar is ribose c. thymine is absent; in its place is uracil |
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3 kinds of cellular RNA are based on their function in protein synthesis, what are they?
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i. mRNA = messenger RNA
ii. tRNA = transfer RNA iii. rRNA = ribosomal RNA |
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4th kind of RNA
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not cellular: Genetic material of RNA viruses = Retroviruses
D. (ex. HIV that causes AIDS) |
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Function of DNA
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1. Each different gene has a different base sequence, each coding for a unique protein (or other product)
2. The sequence of bases in DNA determines the sequence of amino acids in the protein (primary structure) 3. Proteins (enzymes) are extremely important, as most of the cell’s genetic machinery is concerned with coding for specific proteins |
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Flow of information transfer in cell
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(“Central Dogma” not wholly true any more)
transcription translation a. DNA -->RNA--> protein “expression of the gene” or: DNA--> RNA (regulates activity of other genes!!) |