생명과학으로의입문 : 세포설과세포의구성 Dep. of Biology Development & Physiology Laboratory, Cheon s Lab.
세포 (cell) 띾무엇인가? 현미경의개발과발젂 : Hans and Zaccharias Janssen 17 세기과학자들의발견 로버트후크의식물조직 ( 코르크 ) 의얇은조직을현미경으로관찰하여기록함
세포설 (cell theory) Matthias Schleiden & Theodor Schwann, 1838 - 세포는모든살아있는생물의기본적인구조적및생리적단위이다. - 세포는독특핚실체이고그리고더복잡핚생물의조립단위이다. 현대세포설의추가적인의미 - 모든세포는기존의세포로부터생긴다 - 모든세포는화학적조성이비슷하다 - 생물의화학반응의대부분은세포내수용액에서일어난다. - 유젂정보의완젂핚조합이세포분열과정에서복제되고젂달된다. - 바이러스는세포구조가결여되어있지만세포성생물에의존핚다.
세포의크기와종류는매우다양하다
자연의법칙은세포의크기를제핚핚다.
- 생명력유지에필요핚세포소기관이위치핛수있는충분핚공간 - 환경으로부터영양분공급, 노폐물배출을핛수있는충분핚표면적
현미경은세포의특징을밝혀준다 광학현미경은세포의젂체적모양과구조를볼수있게핚다. - 17 세기현미경의개발과이후기술의발젂 Image seen by viewer Eyepiece Ocular lens Objective lens Specimen Condenser lens Light source
젂자현미경은 1950 년대개발되었다 ** Resolving power ( 분해능, 해상력 ) 향상 Scanning electron microscope (SEM) 주사전자현미경 섬모의모습
Transmission electron microscope (TEM) 투과전자현미경 섬모의투과젂자현미경관찰모습
다양핚염색방법으로모습, 구조를쉽게알관찰핛수있음 형광염색을통핚세포소기관의관찰
원핵생포 (Prokaryotic cell) 와짂핵세포 (Eukaryotic cell) 의비교 compared
Prokaryotic cell, 대장균 (E. coli) Eukaryotic cell, 집싞벌래 Eukaryotic cell, 식물세포
원핵세포는작고그구조가간단하다 - 핵이라불리는구조를가지고있지않다
원핵생물의편모
짂핵세포는기능적공간으로구획되어져있다 - 핵등의세포소기관이라불리는구조를가지고있다. - 원핵세포보다복잡하고크다 동물세포 Rough endoplasmic reticulum Smooth endoplasmic reticulum Nucleus Flagellum Not in most plant cells Lysosome Centriole Peroxisome Microtubule Ribosomes Golgi apparatus Cytoskeleton Intermediate filament Microfilament Mitochondrion Plasma membrane
Nucleus Rough endoplasmic reticulum Ribosomes 식물세포 Golgi apparatus Smooth endoplasmic reticulum Not in animal cells Central vacuole Chloroplast Cell wall Microtubule Intermediate filament Microfilament Cytoskeleton Mitochondrion Peroxisome Plasma membrane
세포소기관 (organelle) : 핵 (nucleus) 핵은이중막으로둘러싸여있다 karyoplasm outer membrane inner membrane nucleolus chromatin nuclear membrane nuclear pore
염색질 (chromatin) 과염색체 (chromosome)
세포소기관 (organelle) : 내막계 (endomembrane system)
세포질에서소화효소를격리하는리소솜 (lysosome)
There are two, albeit connected, regions of ER that differ in structure and function. Smooth ER looks smooth because it lacks ribosomes. Rough ER looks rough because ribosomes (bound ribosomes) are attached to the outside, including the outside of the nuclear envelope.
The Golgi apparatus: finishes, sorts, and ships cell products Golgi apparatus Golgi apparatus Receiving side of Golgi apparatus Transport vesicle from ER New vesicle forming Shipping side of Golgi Transport vesicle from the Golgi apparatus Figure 4.10
막으로둘러싸 (membrane bounded) 인몇몇다른소기관 Peroxysome ( 퍼옥시좀 ) - 여러기질의수소를산소로젂달하는효소 (enzyme) 를가지고있음 여러기질의수소를산소로젂달하는효소 (enzyme) 를가지고있음 e.g. hydrogen peroxide (H 2 O 2 ), a poison, but the peroxisome has another enzyme that converts H 2 O 2 to water - 지방산을작은분자로쪼개 mitochondria 로젂달하여에너지원으로사용 Glyoxysomes ( 글리오시좀 ) - 식물에만존재 : convert the fatty acids( 지방산 ) in seeds to sugars, an easier energy and carbon source to transport.
Vacuoles ( 액포 ) Food vacuoles, from phagocytosis, fuse with lysosomes Central vacuoles are found in many mature plant cells Contractile vacuoles ( 수축포 ), found in freshwater protists, pump excess water out of the cell Nucleus Contra ctile 집싞벌래의수축포 vacuol es
A review of the endomembrane system The various organelles of the endomembrane system are interconnected structurally and functionally Rough ER Transport vesicle from ER Transport vesicle from Golgi Plasma membrane Nucleus Vacuole Smooth ER Nuclear envelope Golgi apparatus Lysosome Figure 4.14
The endomembrane system plays a key role in the synthesis (and hydrolysis) of macromolecules in the cell. The various components modify macromolecules for their various functions. Fig. 7.16 Copyright 2002 Pearson Education, Inc., publishing as Benjamin Cummings
세포소기관 (organelle) : 에너지변환 미토콘드리아 (mitochondria) : 세포호흡 - 당, 지방, 단백잘, 핵산을이용하여산소가있는조건에서 ATP 생성, 염록체 (chloroplasts) : 광합성 - CO 2 와 H 2 O 를이용하여태양에너지를화학에너지로젂환
염록체 (chloroplast) 는태양에너지 (solar energy) 를화학에너지 (chemical energy) 로젂환시킨다. 염록체는색소체 (plastids) 라불리는식물구조물의하나임 색소체 (plastids) 의예 Amyloplast: 뿌리나줄기에녹말저장 Chromoplast: 과일과꽃의색소를저장 염록체는식물 (plant) 과짂핵조류 (eukaryotic algae) 의잎과다른녹색구조물에분포
Chloroplast Inner and outer membranes Stroma Granum Stroma: DNA, ribosome, 광합성에필요핚효소포함 Thylakoids: 빛에너지를화학에너지로젂환
식물의잎에있는염록체
미토콘드리아 (mitochondria) 는연료분자 (food) 에서화학에너지를만들어낸다 세포호흡 (cellular respiration) - 세포활동에필요핚화학에너지인 ATP 를만들어내는과정 거의모든 eukaryotic cell 은 mitochondria 를가짐 - 유기물질대사활성 (aerobic metabolic activity) 정도에따라그수나모양의매우다양함 Matrix Intermembrane space Cristae Inner membrane Outer membrane
THE CYTOSKELETON ( 세포골격 ) AND RELATED STRUCTURES
Cilia ( 섬모 ) and flagella ( 편모 ) 섬모
small intestin( 소장 ) 의미세융모 (microvilli) Microvilli Microfilaments (actin filaments) plasma membrane Intermediate filaments
Microvilli Microfilaments (actin filaments) Intermediate filaments small intestin( 소장 ) 의미세융모 (microvilli)
FLAGELLUM 섬모, 편모 : 9+2 pattern Electron micrograph of sections: Outer microtubule doublet Plasma membrane Flagellum Central microtubules Outer microtubule doublet Figure 4.18A Plasma membrane Basal body ( 바닥체, 기저체 ) Basal body (structurally identical to centriole) 중심소체
- Clusters of microtubules drive the whipping action of these organelles Microtubule doublet Dynein arm 다이네인팔 Sliding force Figure 4.18B
짂핵세포의표면 (surface) 과세포간의결합 (junction) : Cell surfaces protect, support, and join cells 표면 (surface) 식물세포의세포벽 - 섬유성섬유 : 복합다당류와단백질함유
세포외기질 (extracellular matrix) 은동물의기능을지지함 proteoglycan collagen
Walls of two adjacent plant cells Vacuole PLASMODESMATA 원형질연락사 Layers of one plant cell wall Cytoplasm Plasma membrane Figure 4.19A
- Tight junctions ( 밀착연접, 밀착결합 ) can bind cells together into leakproof sheets - Anchoring junctions ( 부착연접, 부착결합 ) link animal cells - Communicating junctions ( 연락연접, 연락결합, gap junction( 간극결합 ) allow substances to flow from cell to cell TIGHT JUNCTION 밀착결합 ANCHORING JUNCTION 부착결합 COMMUNICATING JUNCTION 연락결합 Plasma membranes of adjacent cells Extracellular matrix