BIOL 151 1st Edition Lecture 13 Outline of Last Lecture - Chloroplastso Overview- Calvin cycleo Carbon fixation-Rubiscoo Sugar synthesis- Light-dependent reactionso PhotosynthesisOutline of Current Lecture - Chromosomes- Mitosiso Chromosome dynamico Cytoskeletal arrays- CytokinesisCurrent LectureA. Mitosis Stages: eukaryotic specific; process by which complete copies of an organism DNA (genome) are moved into separate cells 1. Prophase: a. hallmark: chromosome condensation; copies are spatially separated b. chromatin fibers become more tightly coiledc. nucleoli disappears d. each duplicated chromosome appears as 2 identical sister chromatids joined at centromerese. mitotic spindle begins to form (composed of centrosomes and MT’s that extend from themi. Mitotic Spindle: centrosome splits → two spindles with two spindle poles (area that initiates growth, center of mitotic spindle)ii. MTOC: centrosome and spindle polesiii. split MTOC in half→ sent to each side of the cellf. centrosomes move away from each other, propelled by MT’s between them g. Kinetochore: proteins; have motors; hook on the microtubules; motors go in opposite directions; keep moving until force is balanced and resides in the centerThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.2. Prometaphase: includes NE breakdown, spindle-growth, chromosome attachmenta. MT’s from centrosome invade nuclear areab. chromosomes are more condensedc. each of the 2 chromatids have kinetochore (protein at centromere)d. some MT’s attach to kinetochore→ jerks chromosomes back and forth3. Metaphase: chromosomes lined up down the equator ⇒ metaphase plate; centromeres split right down the middle; tension helps split → motors work, tension still presenta. centrosomes are at opposite poles of cellsb. chromosomes are at metaphase plate → chromosome’s centromeres lie at metaphase platec. for each chromosome, kinetochores of sister chromatids are attached to kinetochore MT’s coming from opposite poles4. Anaphase: hallmark: chromosomes move to the spindle poles; partially driven by motors;partially driven by MT depolymerizationa. splits 2 sister chromatids → chromatid becomes chromosomeb. daughter chromosomes move centromere first to opposite poles of the cell5. Telophase: take everything apart phase; chromosome decondensation (unpackaging); reformation of nuclear envelope; take spindle apart; 2 collections of DNA and the end of telophasea. 2 daughter nuclei form in the cell → nuclear envelopes form and nucleoli reappearb. chromosomes become less condensedB. Cytokinesis: splitting of the cytoplasm to form 2 daughter cellsI. In animal cells: pinching, golgi disapearsA. form array of microfilaments across equator in a ring ⇒ contractile ringB. tighten ring, drives deformationC. end result: two separate cellsD. Cleavage furrow II. In plant cells: involves building a wall between daughter cellsA. 2 nucleiB. microtubulesC. + in the middle, - on endsD. array made of microtubules ⇒ phragmoplast1. build wall inside outE. plants keep golgi: makes cell wall material which is made up of polysaccharides (sugars) (whereas animal cells do not keep their golgi)F. Vesicles walk to middle from golgi, fuse into continuous compartment filled with cell material ⇒ cell plate: where vesicles fuse1. keep adding material until it fuse to old wall, separating cell into 2 daughter