Biochemistry and the Organization of Cells PDF

1 Biochemistry and the Organization of Cells 1-1 1 1-2 1 hepatocyte 분화 (differentiation) osteoblast melanocyte 1-3 1 1-4 1 1-5...

1 Biochemistry and the Organization of Cells 1-1 1 1-2 1 hepatocyte 분화 (differentiation) osteoblast melanocyte 1-3 1 1-4 1 1-5 1 Homeostasis 1-6 1 Some Basic Themes All living things make use of the same types of biomolecules, and all use energy as a result, all living things can be studied using the methods of chemistry and physics The fundamental similarity of cells of all types makes it interesting to speculate on the origins of life. both cells and the biomolecules of which they are made must have arisen ultimately from very simple molecules, such as H2O, NH3, CO2, N2, and H2. 1-7 1 1-8 1 Sunlight is the ultimate source Photosynthetic organisms are the ultimate of all biological energy. Providers of fuels in biosphere. 1-9 1 Energy coupling in mechanical and chemical process. 1-10 1 Biomolecules Organic chemistry: the study of the compounds of carbon the cellular apparatus of living organisms is made up of carbon compounds biomolecules are part of the subject matter of organic chemistry the reactions of biomolecules can be described by the methods of organic chemistry. Functional group: an atom or group of atoms within a molecule that shows characteristic physical and chemical properties 1-11 1 화합물 일반구조 기능기 기능기명칭 보기 1-12 1 1-13 1 s 껍질은 2개가 최대, p 껍질은 6개가 최대, d 껍질은 10개가 최대, f 껍질은 14개가 최대 1-14 1 1-15 1 Functional Groups 1-16 1 1-17 1 Origins of Life Table 1.1 Relative Abundance of Important Elements Numer of Atoms Relative to 1000 Atoms of Carbon Carbon Abundance Abundance in Element in Organisms the Universe H 80-250 10,000,000 C 1,000 1,000 N 60-300 1,600 O 500-800 5,000 1-18 1 Origins of Life Abundance Abundance in Element in Organisms the Universe Na 10-20 12 Mg 2-8 200 P 8-50 3 S 4-20 80 K 6-40 0.6 Ca 25-50 10 Mn 0.25-0.8 1.6 Fe 0.25-0.8 100 Zn 0.1-0.4 0.12 1-19 1 Biomolecules Gases present in the atmosphere of the early earth included NH3, H2S, CO, CO2, CH4, N2, H2, and H2O. Experiments have demonstrated that important biomolecules, such as proteins and nucleic acids, could have arisen under abiotic (nonliving) conditions from reactions of these simple compounds in the earth and oceans on the surface of clay particles 1-20 1 Biomolecules Living cells include very large molecules, such as proteins, nucleic acids, and polysaccharides these biomolecules are polymers (Greek: poly + meros, many + parts) they are derived from monomers (Greek: mono + meros, single + part) --amino acids -> proteins --nucleotides -> nucleic acids --monosaccharides -> polysaccharides 1-21 1 Biomolecules Enzymes: a class of proteins, are biocatalysts the catalytic effectiveness of a given enzyme depends on its amino acid sequence Genetic code: the relationship between the nucleotide sequence in nucleic acids and the amino acid sequence in proteins theories of the origin of life consider how such a coding system might have arisen 1-22 1 1-23 1 A linear metabolic pathway 1-24 1 1-25 1 The complementary structure of DNA 1-26 1 스스로 복제하는 RNA의 진화과정. 단계가 진행될 때 마다 점차 복잡해지므로 결국 가장 효과적인 촉매인 단백질 합성이 이루어 진다. 1-27 1 1-28 1 Landmarks in the evolution of life on Earth 1-29 1 Organism can be classified according to their source of energy (sunlight or oxidizable Chemical compounds) and their source of carbon for the synthesis of cellular material. 1-30 1 Prokaryotes and Eukaryotes Prokaryote: Greek derivation, meaning before the nucleus? single-celled organisms include bacteria and cyanobacteria Eukaryote: Greek derivation, meaning true nucleus contain a well-defined nucleus surrounded by a nuclear membrane can be single celled, such as yeasts and Paramecium, or multicellular, such as animals and plants 1-31 1 Living cell 1-32 1 Common structural features of bacterial cells 1-33 1 Table 1.3 Differences between the two cell types Organelle Prokaryotes Eukaryotes Nucleus No definite nucleus; DNA Present present but not separate from the rest of the cell Cell membrane Present Present Mitochondria None; enzymes for oxidation Present are on plasma membrane Endoplasmic None Present reticulum Ribosomes Present Present Chloroplasts None; photosynthesis Present in localized in chromatophores green plants 1-34 1 1-35 1 1-36 1 1-37 1 Svedberg Unit: 침강계수 1-38 1 1-39 1 Table 1.4 Organelles of and Their Functions Organelle Function Nucleus Location of main genome; site of most DNA and RNA synthesis Mitochondrion Site of energy-yielding oxidation reactions; has its own DNA Chloroplast Site of photosynthesis in green plants and algae; has its own DNA Endoplasmic Continuous membrane throughout reticulum the cell, rough part studded with ribosomes, the sites of protein synthesis ER is involved in protein synthesis or in the synthesis of cholesterol and lipids. 1-40 1 Table 1.4 (contd.) Golgi Series of flattened membranes; involved apparatus in secretion of proteins from cells and in reactions that link sugars to other cellular components Lysosomes Membrane-bounded sacs containing hydrolytic enzymes Peroxisomes Sacs that contain enzymes involved in the metabolism of hydrogen peroxide Cell membrane Separates the cell contents from the outside world Cell wall Rigid exterior layer of plant cells Central vacuole Membrane-bound sac (plant cells) 1-41 1 The Five Kingdoms Monera only prokaryotic organisms; includes bacteria and cyanobacteria Protista includes unicellular organisms such as yeast, Euglena, Volvox, Amoeba, and Paramecium Fungi includes molds and mushrooms Plantae Animals 1-42 1 Evolution of eukaryotes 1-43 1 Common Ground for Cells Eukaryotes are complex; how did such cells arise from simplest progenitors? Mutualism: a symbiotic association between two organisms that gives rise to a new organism combining characteristics of both original types the lichen, which consists of a fungus and an alga the root nodule system formed by a leguminous plant and anaerobic nitrogen-fixing bacteria humans and bacteria, such as Escherichia coli, that live in the intestinal tract 1-44 1 세영역의 분류체계. 세균계와 원시세균계가 원핵생물을 구성하며, 세번째인 진핵세포계가 진핵생물영역이다. 세영역 모두 진화의 초기에 공통 조상을 갖는다. 1-45 1 Common Ground for Cells Hereditary symbiosis; a host cell contains a genetically determined number of smaller organisms the protist Cyanophora paradoxa, a eukaryotic host, that contains cyanobacteria; this example of endosymbiosis (the smaller organisms are contained within the host) is considered a model for the origin of chloroplasts a similar model can be proposed for the origin of mitochondria; a large anaerobic host cell assimilates a number of smaller aerobic bacteria large unicellular organisms that assimilated anaerobic aerobic bacteria whet on to evolve mitochondria from bacteria and eventually gave rise to animals 1-46 1 Common Ground for Cells other types of unicellular organisms assimilated both aerobic bacteria and cyanobacteria and evolved both mitochondria and chloroplasts; they eventually gave rise to green plants These proposed connections between prokaryotes and eukaryotes are not established with complete certainty Still they provide an interesting framework from which to consider the reactions that take place in cells 1-47 1 A plausible theroy for the evolutionary origin of mitochondria and chloroplasts. 1-48 1 1-49 1 1-50