Transcript CH3- part1
Basic unit of ___________. The form of each cell is relevant to the cell’s _______________. Multicellular organisms have cells that have differentiated and become grouped into tissues that work to sustain the life of the animal. Cells Essential structures of the cell: 1. _________ ____________________ (also known as plasma membrane or less commonly, plasmalemma). Forms a flexible barrier that separates the intracellular and extracellular environment. 2. ___________________ Location of everything inside the cell membrane but outside the nucleus. ________ (gelatinous) material that contains proteins, electrolytes, metabolites (product of metabolism), cytoskeleton, and organelles. 3. ___________________ Contains the genetic material of the cell. Many invaginations allow for increased _____________ area. Capable of _____-repair as long as intracellular components are not leaked. Allows movement of molecules in and out of the cell. Consists primarily of ________ and ____________. ____________ ____________: composed of two layers of phospholipid molecules and globular and structural proteins Cell Membrane Structure of the Cell Membrane lipid bilayer ◦ _____________ “heads”are on outside (______________) ◦ _______ ______ “tails” are on the inside (______________) ◦ Proteins that are WITHIN the bi-layer These proteins span the entire width of the membrane and create passageways through for molecules can pass through. ◦ Passageways may be selective ____________ and permit only certain molecules in or out of the cell. ◦ Passageways may contain _____________ that allow substances to pass freely without resistance. Integral Proteins Proteins which can be bound to the OUTER OR INNER surfaces of the cell membrane. ◦ Those inside the cells are somewhat limited in their movement because they can have attachments to integral proteins or to the cytoskeleton. ◦ Can act as enzymes ◦ Can change the cell’s shape. Peripheral Proteins _________________– “sugar coating” on the surface of some cells ◦ Made of glycoproteins and glycolipids. ◦ Unique to each cell – provides markers for recognition, interactions, and bonding. Cell Membrane: External Surface Extensions of the cell membrane that project into the extracellular space. Energetic, motile hairs Composed of 9 pairs of microtubules that encircle a central pair Flagella and Cilia Occur in large numbers on the exposed surface of some cells. ◦ _________ than flagella and move synchronously to create waves of motion for propulsion. Functions: to move substances over the cell surface. ◦ In upper respiratory tract, propel bacteria and mucus from the lungs ◦ In oviduct, guides egg from ovary into oviduct. Cilia Significantly ___________ than cilia and usually occur as a single structure. ◦ Function: aid in the movement of a cell through fluid. Tail of sperm is a flagellum Flagellum The inner substance of the cell, excluding the __________ . Components include: Cytoplasm The ______ of the cell ◦ Viscous, semi-transparent liquid composed of dissolved electrolytes, amino acids, and simple sugars. Proteins suspended within fluid give fluid its thick, _____ -like consistency. ◦ These proteins are enzymes that are important in metabolic activities of the cell. Cytosol ____________ for the cells. Gives support and shape to the cell, enables cell to move. Anchors ____________. 3 types of fibers that comprise cytoskeleton: Cytoskeleton ◦ Long and hollow tubes that grow from the cell ________. ◦ Form cables that __________ attach to and then move throughout the cell when they are pushed by proteins. ◦ Can be disassembled and reassembled to form new paths ◦ Composed of pairs of proteins called ___________ Cytoskeleton- Microtubules ◦ Woven, ropelike fibers that are able to resist pulling forces on the cell ◦ __________ and most _____________ part of the cytoskeleton. Cytoskeleton- Intermediate Fibers ◦ Located near the cell ________ ◦ Arranged in bundles. ◦ Composed of actin (contractile protein) ◦ Play key role in cell’s ability to change shape, break apart during cell division, and have invaginations in the cell wall Cytoskeleton- Microfilaments