Bio 101 Notes for final Chapter 9 Cellular Respiration Cellular respiration includes both aerobic and anaerobic processes but most commonly called aerobic respiration It can occur with or without the presence of O2 Food provides fuel for respiration and CO2 and H20 are the products The overall process can be summarized as Organic compounds O2 CO2 water energy The cell converts glucose into ATP by cellular respiration Redox reactions Oxidation and Reduction The transfer of electrons during chemical reactions releases energy stored in organic molecules The released energy is ultimately used to synthesize ATP Oxidation and Reduction transfer of electrons in a chemical reaction that releases energy They re used to synthesize ATP Oxidation Substances loses electron oxidized Reducing agent Reduction Substance gains electron The positive charge is reduced oxidizing agent During cellular respiration the fuel glucose is oxidized and O2 is reduced You can divide cellular respiration into 3 metabolic processes that each occur in a specific region of the cell 1 Glycolysis in the cytosol cytoplasm 2 Citric Acid Cycle Krebs Cycle in the matrix of the mitochondria 3 Oxidative Phosphorylation via ETC in the inner mitochondrial membrane In the absence of oxygen respiration consists of two metabolic pathways which both are in the cytosol 1 Glycolysis 2 Fermentation Formula for respiration C6H12O6 6O2 6H2O Energy ATP Heat 1 Glycolysis splitting of sugar The 6 carbon sugar glucose is broken down into molecules of a 2 carbon molecule pyruvate It can take place with or without O2 Start point glucose 2 ATP 4ADP 2Pi End point 2 pyruvate 2 NADH 2 ADP 4 ATP with a net gain of 2 ATP and 2 NADH Glycolysis can be divided into two phases 1 Energy Investment Phase 2 Payoff Phase Energy Investment Phase Glucose is the starting product 2 ATP 4 ADP 2Pi 2 ATP is used to break glucose in half into 2 phosphoglyceraldehyde PGAL Energy Payoff Phase 2 PGAL is transformed into 2 pyruvate Each PGAL pyruvate produces 2 ATP 4 total and 1 NADH 2 total At the end of glycolysis all the energy that was originally in glucose is now in 3 different kinds of molecules 2 ATP 2 NADH and 2 pyruvate 2 Kreb s Cycle It s a key components of the metabolic pathway by which all aerobic organisms generate energy Occurs in the mitochondrial matrix and only in the presence of O2 It completes the breakdown of glucose to CO2 It generates a pool of chemical energy ATP NADH and FADH2 from the oxidation of pyruvate which is the end product of glycolysis In the Kreb s Cycle pyruvate is transported into the mitochondria and loses CO2 to form acetyl CoA NAD is reduced to NADH When acetyl CoA is oxidized to CO2 in the cycle chemical energy is released and captured into the form of NADH FADH2 and ATP In this cycle it consumes Acetate in the form of Acetyl CoA and reduces NAD and NADH and produces CO2 The final product at the end of the cycle is oxaloacetic acid It is known as the citric acid cycle because citric acid is the very first product generated by the sequence of chemical conversions as well as what is regenerated at the end of the cycle The cycle oxidizes organic fuel from pyruvate and Per acetyl CoA that enters the cycle it generates 2 NADH 1 FADH2 1 GTP ATP 3 Oxidative Phosphorylation via ETC Converts the energy from NADH and FADH2 into ATP It accounts for most of the ATP synthesis and occurs in the inner mitochondrial membrane It s powered by redox reactions Accounts for almost 90 of ATP generated by cellular respiration A smaller amount of ATP is formed in glycolysis Kreb s cycle by substrate level phosphorylation Uses energy from NADH and FADH2 to pump hydrogen ions H from mitochondrial matrix into the intermembrane space Then by allowing H to flow back into the matrix in a controlled way ATP is synthesized End result roughly 38 ATP generated For the Electron Transport Chain NADH and FADH2 pass their electrons through the protein complexes until they reach O2 the final electron acceptor Those electrons passing through the complexes causes a change in the protein that causes hydrogen ions to be pumped from the mitochondrial matrix to the intermembrane space where they build up and to get back to equilibrium they travel back into the intermembrane space through ATP synthase chemiosmosis The ATP synthase harnesses that energy proton motive force and uses it to phosphorylate ADP to make ATP Oxidation phosphorylation consists of 1 Electron Transport Chain 2 Chemiosmosis ETC Electrons are passed through a number of proteins to O2 the final electron acceptor It consists of a series of molecules mostly proteins embedded in the inner mitochondrial membrane Chapter 12 The Cell cycle and Mitosis Cell division the reproduction of cells 2 kinds The purpose of cell division is reproduction of cells growth and development of organism and to repair damage of tissues Mitosis Produces somatic cells Diploid Identical Meiosis takes place in germ reproductive cells Produces gametes sperm egg Haploid Non identical daughter cells that have 1 set of chromosomes as many as parent cell The cell cycle The cell cycle consists of two phases 1 Mitotic M Phase cell division phase a Mitosis division of the nucleus b Cytokinesis division of the cytoplasm 2 Interphase cell growth and copying of chromosomes in prep for cell division a G1 phase the first gap b S phase synthesis c G2 phase second gap The M phase is the shortest part of the cycle The M phase alternates with a longer stage Interphase which accounts for about 90 of the cycle Intense metabolic activity occurs throughout interphase During all sub phases a cell grows by producing proteins and cytoplasmic organelles such as mitochondria and endoplasmic reticulum ER Cell grows and prepares for DNA replication in the G1 phase Duplication of chromosomes occurs in the S phase Further growth takes place in G2 phase Finally mitosis occurs in the M phase Mitosis is divided into 5 phases 1 Prophase 2 Prometaphase 3 Metaphase 4 Anaphase 5 Telophase 1 Prophase The genetic material is already duplicated from interphase Chromatin become coiled condenses into chromosomes and can be viewed under microscope each with 2 sister chromatids X shaped Cell builds mitotic spindle Each duplicated chromosome is seen as a pair of sister chromatids joined by duplicated but unseparated centromere Nucleolus disappears Nuclear envelope disappears at the end which signals the next substage 2 Prometaphase Spindle microtubules attach to DNA and