https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/membrane-permeability/v/cell-membrane-introduction 2023-06-22T15:57:36.106541556Z Cell membrane introduction The cell membrane is made up of phospholipids, which have a hydrophilic phosphate head, a glycerol backbone, and two hydrophobic fatty acid tails. The phospholipids form a bilayer with the hydrophilic heads facing outward. This bilayer is semi-permeable meaning that it allows some substances to pass through while blocking others. William Tsai video https://cdn.kastatic.org/googleusercontent/BOP_7ArtE_8sGQn0s_C1le8WEVsKbOwwXtTKspEfzLQwRw69WoSlfvbHynVF4NFZPZOOKxbloveEnONZ-Vl17J8 Cell membrane introduction The cell membrane is made up of phospholipids, which have a hydrophilic phosphate head, a glycerol backbone, and two hydrophobic fatty acid tails. The phospholipids form a bilayer with the hydrophilic heads facing outward. This bilayer is semi-permeable meaning that it allows some substances to pass through while blocking others. https://cdn.kastatic.org/ka-youtube-converted/QpcACa39YtA.mp4/QpcACa39YtA.mp4 532 Cell membrane and techniques used to study it https://www.khanacademy.org/science/grade-11-biology-snc-aligned/x58c107ba92d3f0b2:domain-d-cells-and-sub-cellular-organelles/x58c107ba92d3f0b2:cell-membrane-and-techniques-used-to-study-it/e/cell-membrane-questions 2025-04-14T22:34:53.782134477Z Cell membrane questions Cell membrane questions Jeff Collins exercise https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/plasma-membranes/v/fluid-mosaic-model-of-cell-membranes 2024-06-28T21:04:33.970147436Z Fluid mosaic model of cell membranes The fluid mosaic model explains the structure of cell membranes. These membranes are composed of phospholipids, forming a bilayer with hydrophilic heads facing outwards and hydrophobic tails facing inwards. Proteins, glycolipids, glycoproteins, and cholesterol are embedded within this bilayer, creating a diverse "mosaic". The "fluid" aspect refers to the flexibility and movement within the membrane, maintaining separation between the cell's interior and exterior. Sal Khan video https://cdn.kastatic.org/googleusercontent/OANXnaQoXmd-6-vlyX0lVAIuHYjNz65PuAzGhdele8AZ4fFSOjGFkL2gFnm9426GD_RyuWvmqnxBbgxqkXnFNLGb Fluid mosaic model of cell membranes The fluid mosaic model explains the structure of cell membranes. These membranes are composed of phospholipids, forming a bilayer with hydrophilic heads facing outwards and hydrophobic tails facing inwards. Proteins, glycolipids, glycoproteins, and cholesterol are embedded within this bilayer, creating a diverse "mosaic". The "fluid" aspect refers to the flexibility and movement within the membrane, maintaining separation between the cell's interior and exterior. https://cdn.kastatic.org/ka-youtube-converted/cP8iQu57dQo.mp4/cP8iQu57dQo.mp4 527 Cell membrane and techniques used to study it https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/membrane-permeability/e/membrane-permeability-exercise 2021-04-29T07:53:08Z Membrane permeability Test your knowledge of membrane permeability! Haider Ali Bhatti exercise https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/plasma-membranes/a/hs-the-cell-membrane-review 2021-04-29T07:58:54Z The cell membrane review article https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/membrane-permeability/a/fluid-mosaic-model-cell-membranes-article 2022-05-13T20:48:32.676099881Z Fluid mosaic model: cell membranes article article https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/plasma-membranes/v/cell-membrane-proteins 2023-08-14T21:12:46.061619254Z Cell membrane proteins Proteins comprise 75% of the cell membrane's mass, and play key roles in cellular processes. Explore the differences between integral, peripheral, and lipid-bound proteins, and discover how channel and carrier proteins maintain cellular balance. You'll also learn about the signaling role of glycoproteins in cell recognition. By William Tsai. William Tsai video https://cdn.kastatic.org/googleusercontent/apCfEj1gUWIR3E9wGxY7XzqUewYBAVc-JyfgZjgHf4_79mECtkMtSgZ6fcuKpsEWwcNrVq2rTi5PwhhF6Mtkt70Gnw Cell membrane proteins Proteins comprise 75% of the cell membrane's mass, and play key roles in cellular processes. Explore the differences between integral, peripheral, and lipid-bound proteins, and discover how channel and carrier proteins maintain cellular balance. You'll also learn about the signaling role of glycoproteins in cell recognition. By William Tsai. https://cdn.kastatic.org/ka-youtube-converted/0emD1AmfdjY.mp4/0emD1AmfdjY.mp4 491 Cell membrane and techniques used to study it https://www.khanacademy.org/science/grade-11-biology-snc-aligned/x58c107ba92d3f0b2:domain-d-cells-and-sub-cellular-organelles/x58c107ba92d3f0b2:cell-membrane-and-techniques-used-to-study-it/v/cell-membrane-fluidity 2022-11-16T04:22:43.7414897Z Cell membrane fluidity Cell membrane fluidity is the property of the cell membrane that allows it to adapt its shape and movement to different conditions. Three key factors influence cell membrane fluidity: temperature, cholesterol, and the kind of fatty acids in the phospholipids that form the cell membrane. These factors alter the space and interaction between the phospholipids, and how this affects the fluidity of the cell membrane. William Tsai video https://cdn.kastatic.org/googleusercontent/EkboMM7-i1JD4jUEa4Kq0I2a-Gveyh-0gMlu8OF6ENLzXgZ4Jfhqj1pmZ4-rpYo71X9l-cv2YlDrqDp7529xIuNQ Cell membrane fluidity Cell membrane fluidity is the property of the cell membrane that allows it to adapt its shape and movement to different conditions. Three key factors influence cell membrane fluidity: temperature, cholesterol, and the kind of fatty acids in the phospholipids that form the cell membrane. These factors alter the space and interaction between the phospholipids, and how this affects the fluidity of the cell membrane. https://cdn.kastatic.org/ka-youtube-converted/BWQCAsM-CF4.mp4/BWQCAsM-CF4.mp4 424 Cell membrane and techniques used to study it https://www.khanacademy.org/science/grade-11-biology-snc-aligned/x58c107ba92d3f0b2:domain-d-cells-and-sub-cellular-organelles/x58c107ba92d3f0b2:cell-membrane-and-techniques-used-to-study-it/a/additional-techniques-for-protein-separation-and-analysis 2024-09-10T20:28:05.682567539Z Additional techniques for protein separation and analysis This articles reviews ultracentrifugation and mass spectrometry. article https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/biotechnology/a/gel-electrophoresis 2023-08-07T17:09:37.131449861Z Gel electrophoresis A technique used to separate DNA fragments and other macromolecules by size and charge. article https://www.khanacademy.org/science/grade-11-biology-snc-aligned/x58c107ba92d3f0b2:domain-d-cells-and-sub-cellular-organelles/x58c107ba92d3f0b2:cell-membrane-and-techniques-used-to-study-it/v/phospholipid-structure 2022-11-16T04:22:43.7414897Z Phospholipid structure Phospholipids are molecules that form the cell membrane. They consist of a polar phosphate head group and two nonpolar fatty acid tails joined by a glycerol backbone. The phosphate group can link with different molecules, such as serine or choline, to generate diverse kinds of phospholipids. The fatty acid tails can have cis or trans double bonds, which influence the membrane fluidity. The molecular details of phospholipids and their variations can be drawn as shown. William Tsai video https://cdn.kastatic.org/googleusercontent/uQOBLlmptyMTcMQRRiDQ9tKsQZ4M1A_kCJ2y9W_inQ2mDyuQBgHo5eP9EtievnkolvgL0lGP72lzQ0GYTWFJ4VFc Phospholipid structure Phospholipids are molecules that form the cell membrane. They consist of a polar phosphate head group and two nonpolar fatty acid tails joined by a glycerol backbone. The phosphate group can link with different molecules, such as serine or choline, to generate diverse kinds of phospholipids. The fatty acid tails can have cis or trans double bonds, which influence the membrane fluidity. The molecular details of phospholipids and their variations can be drawn as shown. https://cdn.kastatic.org/ka-youtube-converted/CBEys2CTkgE.mp4/CBEys2CTkgE.mp4 421 Cell membrane and techniques used to study it