Term | Definition |
All eukaryotic cells are composed of... | Plasma membrane, cytoplasm, and nucleus |
Plasma membrane function | Covers and protects the cell, controls what goes in and out, links to other cells, flies certain "flags" to tell other cells what it is |
Fluid Mosaic Model | Describes the arrangement of molecules, such as phospholipids and proteins, within the membrane. Lipids act as a barrier, while proteins act as gatekeepers. |
Phospholipids | Form a lipid bilayer in the membrane made up of hydrophilic heads and hydrophobic tails. |
Glycoproteins | Membrane proteins with a carbohydrate group attached that protrude into the extracellular fluid |
Glycocalyx | Sugary coating surrounding the membrane |
Integral proteins | Extend into or through the bilayer |
Transmembrane proteins | Span the entire lipid bilayer |
Peripheral proteins | Attach to the inner or outer surface but do not extend through the membrane |
Ion Channels (Integral) | Allows specific ion to move through water filled pore |
Carriers (Integral) | Carries specific substances across membrane by changing shape (ex: amino acids) |
Receptors (Integral) | Recognizes specific ligand and alters cell's function in some way |
Enzymes (Integral and Peripheral) | Catalyzes reaction inside or outside cell depending on which direction the active site faces |
Linkers (Integral and Peripheral) | Anchors filaments inside and outside the plasma membrane providing structural stability and shape for the cell |
Cell Identity Markers (Glycoprotein) | Distinguishes your cells from anyone else's |
Selective Permeability | The membrane allows some substances across but not others |
Passive Transport Processes | Diffusion of solutes, diffusion of water, and facilitated diffusion |
Active Transport Processes | Various types of transporters are used and energy is required. Low to high |
Diffusion | Passive spread of particles through random motion from areas of high concentration to areas of low concentration |
Diffusion factors | Concentration gradient, temperature, surface area, and diffusion distance |
Facilitated Dissuion | Requires a specific channel (Channel-Mediated Facilitated Diffusion) or a carrier molecule (Carrier-Mediated Facilitated Diffusion) |
Osmosis | Net movement of water through a selectively permeable membrane from an area of high water concentration to an area of low water concentration |
Tonicity | Concentration of salt solutions in the blood and elsewhere |
Hypotonic | Hemolysis (explodes) |
Hypertonic | Cremation (shrinks) |
Antiporters | Carry two substances across the Membrane in opposite directions |
Symporters | Carry two substances across the membrane in the same direction |
Vesicle | Small spherical sac formed by budding off from a membrane |
Endocytosis | Materials move into a cell in a vesicle formed from the plasma membrane (3 types: receptor mediated, phagocytosis, and bulk phase pinocytosis) |
Exocytosis | Vesicles fuse with the plasma membrane, releasing their contents into the extracellular fluid |
Transcytosis | Combination of endocytosis and exocytosis |
Cytosol | Intracellular fluid surrounding the organelles; the site of many chemical reactions |
Cytoskeleton | Microfilaments, intermediate filaments, microtubules |
Centrosome | Consists of two centrioles and pericentriolar material; located near nucleus |
Cilia | Short, hair-like projections from the cell surface that move fluids along the cell surface |
Flagella | Longer than cilia (ex. sperm cell's tail), move an entire cell |
Endoplasmic Reticulum | Network of membranes in the shape of flattened sacs or tubules |
Rough ER | A series of flattened sacs with a surface studded with ribosomes, which produce proteins, that is connected to the nuclear envelope |
Smooth ER | Network of membrane tubules that do not have ribosomes. Synthesizes fatty acids and steroids, and detoxifies certian drugs |
Golgi Complex | Consists of 3-20 flattened membranous sacs, cisternae, that modify, sort, and package proteins in vesicles to transport them to different destinations |
Lysosomes | Vesicles that form from Golgi that contain powerful digestive enzymes |
Peroxisomes | Smaller than lysosomes, abundant in liver, detoxify toxic substances |
Proteasomes | Continuously destroy unneeded, damaged, or faulty proteins, fund in the cytosol and nucleus |
Mitochondria | Powerhouse of the cell; generates ATP, self-replicate, contain own DNA (from mother only) |
Cristae | Series of folds of the inner mitochondrial membrane |
Matrix | Large central fluid-filled cavity |
Nuclear Envelope | Double membrane that separates the nucleus from cytoplasm |
Nuclear Pores | Numerous openings in the nuclear envelope that control movement of substances b/w nucleus and cytoplasm |
Nucleolus | Spherical body that produces ribosomes |
Genes | Cell's hereditary units, control activities and structure of the cell |
Chromosomes | Long molecules of DNA combined with protein molecules |
Mitosis | Cell cycle in which body cell duplicates and divides in two |
Homologous chromosomes | Two chromosomes that make up each pair |
Diploid cells | Somatic cells that contain two sets of chromosomes |
Interphase | Cell replicates its DNA during S phase |
Prophase | Chromatin fibers change into chromosomes |
Metaphase | Microtubules align the centromeres of the chromatid pairs at the metaphase plate |
Anaphase | Chromatid pairs split at the centromere and move to opposite sides and are then called chromosomes |
Telophase | Two identical nuclei are formed around the identical sets of chromosomes now in their chromatin form |
Cytokinesis | Division of cell's cytoplasm; plasma membrane constricts at its middle (cleavage furrow) |
Meiosis | Reproductive cell division that occurs in the gonads that produces with half the number of chromosomes |
Haploid cells | Gametes contain a single set of 23 chromosomes |