II. Mechanism: Cell Membrane Chemical Transport
- Background
- Cellular membranes (phospholipid bilayer) are selectively permeable
- Lipid soluble substances are non-polar and may move across the cell membrane
- Charged substances (e.g. Electrolytes such as Calcium, Sodium, Potassium) move through water channels in the membrane
- Simple Diffusion
- Simple Facilitated Diffusion
- Transport Proteins (channels, carrier Proteins) allow charged particles to cross the cell membrane
- Unlike active transport, no energy is required, as the molecules are following an osmotic gradient
- Channel Proteins create a hydophilic tunnel through the hydrophobic core of the lipid bilayer
- Aquaporins allow water to rapidly cross cellular membranes
- Channels may be gated (only periodically allowing molecules to pass)
- Carrier Proteins
- Transport Proteins (channels, carrier Proteins) allow charged particles to cross the cell membrane
- Active Transport
- Molecules move against their electrochemical gradient
- Primary Active Transport
- Secondary Active Transport
- Movement against electrochemical gradient is fueled by another molecule moving WITH its electrochemical gradient
- In Cotransport, the 2 molecules move in the same direction across the cell membrane
- In Countertransport, the 2 molecules move in opposite direction across the cell membrane
- References
- Membrane Transport (Wikipedia)
Images: Related links to external sites (from Bing)
Related Studies
| Definition (MSH) | The study of the structure, behavior, growth, reproduction, and pathology of cells; and the function and chemistry of cellular components. |
| Definition (NCI_NCI-GLOSS) | The study of cells using a microscope. |
| Definition (NCI) | The light microscopic study of normal and abnormal cells in fine needle aspirates (FNAs), body cavity fluids, and smears. |
| Definition (NCI) | The study of the internal workings of cells at the microscopic and molecular level.(On-line Medical Dictionary) |
| Definition (CSP) | for thorough searching also see CYTOLOGY. |
| Concepts | Biomedical Occupation or Discipline (T091) |
| MSH | D003585 |
| English | Cytology, CYTOL, cytology (field), Cellular Biologies, Cell Biology, Biologies, Cellular, Biology, Cell, Cell Biologies, Cellular Biology, Biologies, Cell, Biology, Cellular, cell biology, cytology field, biology cell, cellular biology, cytology |
| Finnish | Soluoppi |
| Russian | TSITOLOGIIA, BIOLOGIIA KLETKI, БИОЛОГИЯ КЛЕТКИ, ЦИТОЛОГИЯ |
| Japanese | 細胞学, 生物学-細胞, 細胞生物学, 細胞形態学 |
| French | Biologie cellulaire, Cytologie |
| Italian | Biologia cellulare, Citologia |
| Portuguese | Biologia Celular, Citologia |
| Spanish | Citología, Biología Celular |
| Croatian | CITOLOGIJA |
| Swedish | Cellbiologi |
| Czech | cytologie, biologie buňky, buněčná biologie |
| Polish | Biologia komórki, Cytologia |
| Norwegian | Cellebiologi, Cytologi |
| German | Zytologie |
| Dutch | Cytologie |
Ontology: Cellular Structures (C0243092)
| Definition (FMA) | Cardinal cell part which is demarcated from other cell parts by predominantly bona fide anatomical surfaces. Examples: golgi complex, endosome, myofilament. |
| Definition (NCI) | The components of the cell and how they are arranged. |
| Definition (MSH) | Components of a cell. |
| Definition (CSP) | contents and specific structures of a cell. |
| Concepts | Cell Component (T026) |
| MSH | D022082 |
| SnomedCT | 108351002 |
| English | Cellular structures, cell component, Cell component, cell structures, cell structure, cells structure, cellular structure, cellular structures, cell components, Cell Component, Cell Components, Cellular Structure, Components, Cell, Structure, Cellular, Structures, Cellular, Cellular Structures, Component, Cell, Cellular structure, Cellular AND/OR subcellular structure (body structure), Cellular AND/OR subcellular structure, Cell Structure |
| French | Structures de la cellule, Structures cellulaires, Composants de la cellule, Structure cellulaire, Composants cellulaires |
| Swedish | Cellstrukturer |
| Czech | buněčné struktury, buněčné komponenty |
| Finnish | Solurakenteet |
| Russian | KLETOCHNYE STRUKTURY, KLETKI KOMPONENTY, КЛЕТКИ КОМПОНЕНТЫ, КЛЕТОЧНЫЕ СТРУКТУРЫ |
| Italian | Componenti cellulari, Strutture cellulari |
| Croatian | STANIČNE STRUKTURE |
| Latvian | Šūnu komponenti, Šūnu struktūras |
| Polish | Struktury komórkowe |
| Japanese | 細胞の構造, 細胞構造 |
| Norwegian | Cellestrukturer, Cellekomponenter |
| Spanish | estructura celular Y/O subcelular, estructura celular (estructura corporal), estructura celular, Estructuras Celulares |
| German | Zellulläre Strukturen |
| Dutch | Cellulaire structuren, Structuur, cellulaire |
| Portuguese | Estruturas Celulares |
