ANT 2100 1st Edition Lecture 2 Structure and Function of the Cell Most cells contain three (3) major parts: Plasma membrane, cytoplasm, and nucleus II. Plasma membrane (PM)a. forms outer cell boundaries, separates internal environment of cell from external environment. b. Regulates what gets in and out of the cell c. Composed of lipids (fats), proteins, and carbohydrates (sugars) III. Lipids of PMa.the main lipids of PM are phospholipids (majority) and cholesterol (provides stability) b. Proteins of PM- functions as: c. marker molecules are involved with cell to cell recognition, d. attachment proteins attach cells to other cells e. channel proteins are involved with transportation of substances in and out of a cell f. receptor proteins contain binding sites that can attach to specific substances g. enzymes catalyze (speed up) chemical reactions on either the inner or outer surface of the plasma membrane h. carrier proteins move substances (ions or molecules) from one side of the plasma membrane to the other IV. Carbohydrates of the PMa. are found on the extracellular surface of the plasma membrane (form the glycocalyx) V. Cytoplasm a.Site where most cellular activities take place These 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.b. Contains four (4) main parts cytosol, cytoskeleton, inclusions, and organelles c. cytosol- fluid portion of the cell d. cytoskeleton- “cell skeleton”, provides support and structure, and involved with the movement of cellular structures e. inclusions- miscellaneous substances such as lipids, droplets, hemoglobin, and melanin f. organelles- machinery of the cell which include g. ribosomes which are sites of protein synthesis (contain free and fixed ribosomes) h.endoplasmic reticulum (ER)- has both rough and smooth ER 1. Rough ER (RER) - has ribosomes on the external surface (produces proteins) 2. Smooth ER (SER) - no ribosomes, no role in protein synthesis, function in lipidsynthesis, storage of Ca (calcium) ions in muscle cell, detoxification i. golgi apparatus modifies and packages proteins produced by RER and lipids produced by SERj. lysosomes contains acidic (hydrolytic) enzymes and abundant in phagocytes k.mitochondria is the powerhouse of the cell produces ATP (energy source) ATP is the energysource for cellsVII. Nucleus a. control center of cell, contains DNA (deoxyribonucleic acid) VIII. Other Structures Associated with Cellsa. Cilia is the extension of the plasma membrane that move material over the surface of the cells can be found in lungs, b. Microvilli are finger-like projections of the plasma membrane; they increase surface area, and found in cells which undergo a lot of absorption c. Cell junctions- There are four types of cell junctions1. desmosomes also called anchoring junctions, bind cells to one another 2. hemidesmosomes attach epithelial cells to the basement membrane 3. tight junctions prevent substances from passing between two cells 4. gap junctions are involved with cell to cell