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plasma membrane controls movement of materials into and out of the cell surrounds the cell and nucleus peripheral protein attached loosely to inner or outer surface of membrane integral proteins extends into the membrane transmembrane proteins integral protein that goes all the way through the membrane permeable only small uncharged particles (like H2O and CO2) and hydrophobic molecules (nonpolar like O2 and lipid-soluable molecules like hydrocarbons) freely pass across the membrane impermeable large polar molecules (like glucose) and all ions channel proteins provide passageways through the membrane for certain hydrophilic(water-soluble) substances like polar and charged molecules transport proteins active transport-spend energy(ATP) to transfer materials across membrane recognition proteins distinguish identity of neighboring cells. protrude like an antenna adhesion proteins attach cells to neighboring cells or provide anchors for the internal filaments and tubules that give stability to the cell receptor proteins provide binding sites for hormones or other trigger molecules electron transfer proteins involved in transferring electrons from one molecule to another during a chemical reaction cholesterol distributed throughout bilayer, provides some rigidity to the plasma membranes of animal cells glycocalyx a carbohydrate "coat" covering the outer face of the plasma membrane. provides markers for cell to cell recognition selectively permeable membrane only specific substances pass. solute the substance being dissolved solvent the substance that is the dissolver diffusion movement occurs from higher concentration to lower concentration hypertonic higher concentration of solutes hypotonic lower concentration of solutes isotonic equal concentration of solutes bulk flow the collective movement of substances in the same direction in response to a force or pressure passive transport the movement of substances from regions of higher to lower concentrations and do not require any use of energy simple diffusion the NET movement of substances from an area of higher concentration to lower concentration osmosis the diffusion of water molecules across a selectively permeable membrane dialysis diffusion of solutes across a selectively permeable membrane plasmolysis themovement of water out of a cell that results in the collapse of the cell facilitated diffusion diffusion of solutes through channel proteins in the plasma membrane active transport the movement of solutes against a gradient and requires the expenditure of energy coupled transport simultaneous passive transfer of molecules or ions across biological membranes in a fixed ratio vesicular transport uses vesicles or other bodies in the cytoplasms to move macromolecules or large particles across the plasma membrane exocytosis stuff exiting the cell endocytosis going into the cell phagocytosis cellular eating occurs when undissolved material enters the cell pinocytosis cellular drinking occurs when dissolved substances enter the cell receptor-mediated endocytosis occurs when specific molecules in the fluid surrounding the cells bind to specialized receptors that concentrate in coated pits in the plasma membrane cell junctions serve to anchor cells to one another or provide a passageway for cellular exchange 3 parts to the cell theory 1) all organisms are composed of one or more cells 2) cells are the smallest living things 3) cells come from other cells two main types of cells are: prokaryotic(bacteria) and eukaryotic cytoplasm jelly like substance that fills the cell and suspends cell parts inside organelles specialized bodies within the cell that carry out certain functions nucleus bound by nuclear envelope, phospholipid bilayer similar to plasma membrane. contains DNA ribosomes subunits are manufactured in the nucleus and consist of RNA molecules and proteins endoplasmic reticulum stacks of flattened sacs that make various materials rough ER with ribosomes and creates glycoproteins smooth ER no ribosomes and does various things like making lipids and hormones golgi apparatus modify and package proteins and lipids into vesicles and migrate to plasma membrane and release contents outside the cell lysosomes breakdown food, cellular debris, and foreign invaders like bacteria peroxisome common in liver and kidney cells where they breakdown toxic substances mitochondria carry out aerobic respiration microtubules made of protein tubulin, provide support intermediate filaments maintain shape pf cell microfilament made of protein actin and are involved in cell mobility flagella and cilia structures that protrude from the cell membrane and make wavelike movements to move the cell chloroplasts carry out photosynthesis cell walls found in plants, fungi, protists, and bacteria. devlop outside the plasma membrane and provide support for the cell vacuoles fluid filled membrane bound bodies food vacuoles temporary nutrient receptacle. merge with lysosomes for break down storage vacuoles in plants store starch, pigments, and toxic substances central vacuoles when filled exert tugor pressure on cell walls contractile vacuole in single celled organisms that collect and pump excess water out of cell kinetic energy energy of motion potential energy stored energy oxidation reduction electrons transfer from one atom to another. one atom loses electrons while the other gains first law of thermodynamics energy cannot be created or destroyed second law of thermodynamics disorder(entropy)is continuously increasing activation energy gets reactions started free energy energy available to do work GIBBS free energy free energy in a biological cell endergonic inward energy exergonic outward energy metabolism chemical reactions in biological systems catabolism breakdown of substances anabolism formation of new products or transfer of energy from one substance to another chemical equilibrium when the rate in the forward direction equals the rate in the reverse direction in metabolic reactions enzymes globular proteins that act as catalysts substrate the substance upon which the enzyme acts induced fit the enzyme binds to a specific substrate and either holds them together making a bond easier to form or stresses the bond and makes the bond easier to break cofactors nonprotein molecules that assist enzymes haloenzyme union of the cofacter and the enzyme coenzymes organic cofactors that donate or accept some part of a reaction allosteric activator binds to enzyme and induces enzymes active form allosteric inhibitor binds to the enzyme and induces the enzymes inactive form competitive inhibition a substance that mimics the substrate inhibits the enzyme by occupying the active site noncompetitor inhibition a substance binds to an enzyme at locations other than the active or allosteric site cooperativity when an enzyme becomes more receptive to an additional substrate molecules after one substrate molecule attaches to an active site ATP common source of activation energy for metaboloic reactions carbon the framework of biological molecules hydrocarbons compounds that are only C and H Macromolecules large complex assemblies of molecules Hydrolysis a molecule of water is added to separate macromolecules into their separate subunits. Basically reversing dehydration dehydration synthesis attaching subunits together by covalent bonding a -OH group is removed from one subunit and an H is removed from the other(like taking out water) it is a condensation reaction peptide small protein enzyme catalysis enzymes are 3-D proteins that wrap around and fit snugly on chemicals they work on, speeding up reactions an amino acid contains: an amino group -NH2, a -H, and a carboxyl group -COOH they are all bonded to a central atom peptide bond a covalent bond that links amino acids polypeptides one or more long chains that a protein is composed of monomers small molecules that can join with other similar molecules to form very large molecules polymers a class of synthetic substances composed of multiples of simpler units called monomers 5 classes of amino acids: nonpolar aliphatic R groups, aromatic R groups, polar uncharged R groups, positively charged R groups, negatively charged R groups functional groups imparts certain characteristics to a molecule R represents the side group levels of protein structure primary, secondary, tertiary, quaternary alpha helix hydrogen bonds form along a single chain linking to another amino acid further down the chain beta helix hydrogen bonds occur across two chains linking the amino acids in one chain to those in another domains a section of a protein that folds into a structurally independent unit. functional units primary structure amino acid sequence secondary structure coils and sheets motifs folds and creases tertiary structure three dimensional shape quaternary structure individual polypeptide units associated with an overall structure chaperon proteins helps proteins fold correctly denaturation protein unfolding nucleic acids stores genetic information 4 DNA nucleotides adenine, thymine, cytosine, guanine A pairs with T G pairs with C lipids not soluble in water triglycerides fats, oils, waxes fatty acids hydrocarbons with a carboxyl group(-COOH) at one end of chain saturated fatty acid single covalent bond between each pair of carbon atoms and each carbon has 2 hydrogens (solid at room temp) monounsaturated fatty acid has one double covalent bond and each of the two carbons in this bond has only one H bonded to it polyunsaturated fatty acid like monounsaturated fatty acid except there are 2 or more double covalent bonds phospholipids just like a lipid except one of the fatty acid chains is replaced by a phosphate groups amphipathic molecules that contain both polar and nonpolar regions carbohydrates store energy and provide building materials monosaccharide simplest kind of carb. consists of a single sugar molecule ratio for sugar molecule: 1 carbon:2 hydrogen:1 oxygen disaccharides consists of two sugar molecules joined by a glycosidic linkage polysaccharides series of connected monosaccharides starch principal molecules in plant cells glycogen major energy storage molecules in animal cells cellulose structural molecule in the walls of plant cells chitin structural molecule in the walls of fungus cells