<p>STUDY GUIDE – ENERGY IN CELLS</p><p>ATP - (Adenosine TriPhosphate): Energy storage molecule.  Composed of Adenosine, 3 phosphaters  Energy is released when bond between 2 phosphates is broken  ATP turns into ADP when energy is used. ADP then changes back to ATP when energy is stored.</p><p>PHOTOSYNTHESIS Plants use the sun’s energy to produce food (carbohydrates).</p><p>Chloroplasts: organelle that converts light energy into chemical energy. Chlorophyll is a green pigment in the chloroplast</p><p>Reactants Products</p><p>Chemical Formula: 6CO2 + 6H2O  C6H12O6 + 6O2 Carbon dioxide and water react to form glucose and oxygen gas</p><p>Stage 1: Light Dependent Reactions (requires light) Chloroplasts absorb sunlight. The water molecule is split. A molecule of ATP and oxygen gas are produced.</p><p>Stage 2: Light Independent Reactions: “Calvin Cycle” (does not require light) ATP from stage one used to turn carbon dioxide into glucose (sugar).</p><p>The glucose (carbs) produced are used as “food” for plants, or is eaten by animals for energy.</p><p>CELLULAR RESPIRATION Animals and plants break down glucose to make energy (ATP)</p><p>Mitochondria: are organelles that convert chemical energy in glucose into ATP energy molecules.</p><p>Reactants Products</p><p>Chemical Formula: C6H12O6 + 6O2  6CO2 + 6H2O and ATP* Glucose and oxygen react to form carbon dioxide, water, and ATP</p><p>The end products of photosynthesis are the starting reactants of respiration. The end products of respiration are the starting reactants of photosynthesis.</p><p>Step 1: Glycolysis Glucose is broken down into pyruvic acid. (2 ATP produced) Occurs in cytoplasm Step 2: Kreb’s Cycle (If oxygen present = aerobic)</p><p>Pyruvic acid enters the mitochondria and is broken down. CO2 released (2 ATP produced) Step 3: Electron Transport Chain ; ETC (aerobic)</p><p>Substance from the Kreb’s cycle is broken down. H20 released. (MOST ATP produced)</p><p>When NO oxygen present = Anaerobic respiration</p><p>Fermentation no O2 Temporary process that produces a small amount of ATP when oxygen is not available.  Lactic Acid fermentation: glucose broken down into lactic acid and ATP (muscle cells)  Alcoholic fermentation: glucose broken down into alcohol and ATP (yeast and bacteria) CELLULAR REPRODUCTION</p><p>The Cell Cycle: Interphase: G1 – growth and normal cell activities (Longest Phase) S - DNA Replication (DNA doubles) G2 – the cell prepares to divide Mitosis – the nucleus of the cell divides Cytokinesis – the cytoplasm divides (2 identical daughter cells formed)</p><p>Sister Chromatids – identical chromosomes held together by a centromere</p><p>ASEXUAL REPRODUCTION - MITOSIS (PMAT) . Occurs in somatic (body) cells . Produces 2 identical diploid daughter cells “clones” Diploid – 2n, 46 chromosomes . Sister chromatids separate</p><p>Prophase – nuclear membrane breaks down, spindle fibers form, sister chromatids form, centrioles move the poles Metaphase – sister chromatids line up in the center of the cell attached to spindle fibers by the centromere Anaphase – sister chromatids separate and move to opposite poles of the cell Telophase – 2 new nuclei form</p><p>Cytokinesis: Animal cell – cleavage furrow forms and cytoplasm divides Plant cell – cell plates form to create new cell wall between cells</p><p>Cancer: an abnormal cell that does not obey cell division checkpoints Benign (does not spread) Malignant (spreads)</p><p>SEXUAL REPRODUCTION - MEIOSIS (2 divisions) . Creates gametes (sex cells) Male=sperm Female=egg . Produces 4 haploid daughter cells . Provides genetic diversity (variety of genetic traits)</p><p>Homologous Chromosome Pair: Pair of chromosomes (one maternal, one paternal)</p><p>Crossing Over: homologous chromosomes are lined up together during prophase I, overlapping allows an exchange of DNA between the two. (genetic diversity)</p><p>Meosis I – Meosis II – Prophase I: nuclear membrane breaks down Prophase II – nuclear membrane breaks down Homologous pairs form Sister chromatids form Metaphase I: Homologous pairs line up in the center Metaphase II – sister chromatids line up in center Anaphase I: Homologous pairs separate Anaphase II – sister chromatids separate Telophase I: 2 new nuclei form Telophase II – 2 new nuclei form in each cell</p><p>Cytokinesis: cytoplasm splits, 2 daughter cells formed Cytokinesis: cytoplasm splits, 4 haploid gametes formed</p><p>Fertilization Sperm + Egg  Zygote (23) (23) (46)</p><p>Non-disjunction: when the chromosomes do not separate properly during meiosis. . Can cause genetic defects. Ex. Down syndrome, Trisomy 18 Mutation: an error in a DNA code that is passed to offspring through the gametes.</p>