BIO 1201 1st Edition Lecture 7 Outline of Last Lecture I.Amino AcidsII.NucleotidesOutline of Current Lecture III.CellsIV.Cell MembranesV.Membrane ProteinsVI.Moving Molecules Across a MembraneCurrent LectureI. Cells: fundamental unit of lifea. Cell Theory: all living things are made up of cells and all living cells arise from preexisting living cellsb. Two types of cells:i. Prokaryotes (bacteria and archaea): single-celled; 10x smaller than animaland plant cells; don’t have a nucleusii. Eukaryotes (plants and animals): all multicellular organisms are composedof eukaryotic cells (there are also single-celled eukaryotes, like yeast); contain nucleus and other membrane-bound organelles1. Organelle: structure with a specialized function within a cellII. Cell Membranes: form a barrier between environment and the inside of the cell (cytoplasm)a. Major component of all cell membranes is phospholipids, which are amphipathicb. Phospholipid bilayer is basis for all cell membranes—it involves two layers of phospholipids formed to have hydrophilic sections on the outside and hydrophobic layers facing each other on the insidec. Membranes are semi-permeableThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Oxygen, carbon dioxide, and other small, nonpolar molecules can move across freelyii. Glucose and other large, polar molecules cannot move across d. Membranes are described as fluid mosaics because they are made of several types of molecules and the phospholipids are always in motionIII. Membrane Proteinsa. Channel: tunnel across entire membraneb. Transport: help substances move across membranec. Cell Recognition: enable bodies to distinguish between our own cells and the cells of other organismsd. Receptor: allows signal molecules to bind to ite. Enzymatic: participates in metabolic reactionsf. Junction: assist in cell-to-cell adhesion and communicationIV. Moving molecules across membranea. Passive Transport: diffusion—depends on moving molecules from areas of high concentration to low concentrationi. Happens spontaneously, so does not require energyii. Simple diffusion: small, nonpolar moleculesiii. Facilitated: protein channel is used through which larger molecules can moveb. Active Transport: required to move molecules against a concentration gradient (low to high); requires energyc. Molecules can also be moved in bulki. Endocytosis: brings lots of molecules into cell at onceii. Exocytosis: removes lots of molecules from cell at onceiii. Phagocytosis: brings big things into a
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