BIOL 243 Lecture Notes - Lecture 5: Hyperplasia, Immune System, Golgi Apparatus
Document Summary
Defines changes from formation of cell until it reproduces. Cell grows and carries out functions: cell division (mitotic phase) Period from cell formation to cell division. 3 subphases: g1(gap 1)-vigorous growth and metabolism. Cells that permanently cease dividing are said to be in g0 phase: s (synthetic)- dna replication occurs, g2 (gap 2)-preparation for division. Overview: recall central dogma of bio: dna > rna > proteins. One monomer unit= deoxyribonucleic acid: composed of base, sugar (deoxyribose), and a phosphate, directionality along the backbone 5"(phosphate) to 3" (oh) Double-strand pairing: complementary base matching: a-t, g-c, antiparallel (one strand 5"3", the other3"5") Prior to cell division cell makes copy of dna. Dna helices separated into replication bubbles with replication forks at each end: each strand acts as template for complementary strand. Dna polymerase begins adding nucleotides at rna primer. Polymerases continue from primer: works only in one direction o. Dna ligase splices short segments of discontinuous strand together.