Terms and Concepts on Principles of Plant Biology | BZ 120, Study notes of Botany and Agronomy

Download Terms and Concepts on Principles of Plant Biology | BZ 120 and more Study notes Botany and Agronomy in PDF only on Docsity! BZ 120 Terms & Concepts, Week 6 DNA siructure‘finction, continued from Week 5 complementary strands (A to T.G to C) See Fig. 9-3 DNA’s “information” is contained in the sequence of N-bases {base triplet codesrecipe for protein) semiconservalive replication (of DNA) - sce Fig. 9-4: -helicase (“unzips” double helix) -DNA polymerase (assembles new. complementary stand along each old strand} -replication fork & bubble mutation (change in a genc/DNA sequence) RNA - single-stranded polymer of nucleotides 3 main types of RNA: -ribosomal RNA (rRNA) -messenger RNA (MRNA} -transfer RNA (tRNA) -- see Fig. 9-11 gene segment of DNA with code for | protein‘polypeptide chain genes “work” by interacting with RNA Lo make proteins Protein Synthesis (2 steps in prokaryotes, 3 steps in eukaryotes) - see Fig. 9-8 -transcription (NA > RNA) (always step 1) -translation (RNA > protein) (step 2 in prok.: step 3 in eukaryotes) -RNA splicing (step 2 in eukaryotes; makes MRNA) franscription (see Fig. 9-10) RNA polymerase - assembles RNA along one strand of DNA codon (in mRNA) - base triplet coding for | amino acid — sec Fig. 9-9 stop (or nonsense) codon - can separate codes for different proteins along one MRNA molecule RNA splicing - step 2 in eukaryoles (pre-mRNA > mRNA) -see Fig. 9-19 exons (spliced together) introns (removed in splicing) transfer RNA ((RNA) — sce Fig. 9-1] “shuttles” a specific amino acid to proper position in translation anticodons (only in (RNA) Translation (last step) —3 types of RNA interact Lo assemble protein: like an “assembly line” ribosome is the “factory”’sile: MRNA is the “conveyor belt” with instructions: tRNA is “cart” holding an amino acid Details: mRNA attaches to ribosome; I codon on mRNA attracts (RNA (with its amino acid) with complementary anticodon; 2" codon on mRNA attracts RNA (& amino acid) with complementary anticodon: peptide bond forms between amino acids; mRNA slides across the ribosome so that the [ codan comes off the ribosome and the next (3) codon moves on and attracts a tRNA with a complementary anticodon; 1“ tRNA detatches from mRNA and from its amino acid and goes to pick up another amino acid molecule: process continues, with each mRNA codon (specifying an amino acid) attracting aiRNA anticodon, with the tRNA “transferring” Lhe amino acid to the growing polypeptide chain (protein); when proicin is complete, il is released: the mRNA can attach to another ribosome and the process can begin again, to make another molecule of the protein gene expression (a gene is switched on so its protein is made) transcriptional “switches” (e.g., transcription factors) translational “switches” (e.g., microRNA) ditferentiation -- an unspecialived cell becomes specialized due to differential gene expression cloning — produces genetically identical organisms because it Involves mitosis & cytokinesis c.g... cuttings tissue culture technique to “clone” cells‘plants artificially -- e.g, 32,000 yr.-old frozen plant cells! asexual reproduction (new individuals, genetically identical) sexual reproduction (new individuals. genetically distinct‘different) meiosis division of nucleus in which the number of chromosomes ts cut ip half syngamy'- fusion of 2 haptoid cells (gametes) to form a zygote (- fertilization) life cycle diagram (meiosis & syngamv alternate) diploid (2n} haploid (nj