BSC 109 Lecture 5 Chapter 2, 3Outline of Last Lecture I. Polysaccharides store energyII. Lipids: insoluble in waterIII. ProteinsOutline of Current Lecture:Chapter 2I. Nucleic AcidsChapter 3I. Cell DoctrineII. Cells are classified according to their internal organizationIII. MicroscopesIV. A plasma membrane surrounds the cellV. Molecules cross the plasma membrane in several waysVI. Isotonic extracellular fluid also maintains cell volumeVII. OrganellesCurrent LectureI. Nucleic AcidsA. Long chains of nucleotidesB. DNA1. Contains instructions for producing RNA2. Adenine, thymine, cytosine, guanineThese 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.3. Double strandedC. RNA1. Contains instructions for producing proteins2. Single stranded 3. Uracil, thymine, cytosine, guanine4. Most viruses are RNAD. ATP1. ATP is the body’s energy currency2. Bonds between phosphate groups contain potential energya) Breaking third phosphate releases energyb) ATP (adenosine triphosphate) transforms to ADP (adenosine diphosphate) +P (phosphate)+energyChapter 3I. Cell DoctrineA. All living things are composed of cellsB. A single cell is the smallest unit that exhibits all of the characteristics of lifeC. Current cells division= only source of new cellsII. Cells are classified according tot heir internal organizationA. Prokaryotic cells1. Have DNA, cytoplasm and a plasma membrane2. DON’T HAVE a nucleus and are NOT organellesB. Eukaryotic cells1. Our cells, do have a true nucleus, cytoplasm, plasma membrane, and are considered organellesC. Cells are small but efficient in acquisition of nutrients and disposal of wastesIII. MicroscopesA. Needed to see cellsB. 3 types: light microscope, transmission electron microscope, and scanning electron microscopeIV. A plasma membrane surrounds the cellA. Separates cell from its environmentB. Selectively permeable: permits movement of some substances into and out of the cell, but blocks othersC. Is a phospholipid bilayer1. Cholesterol strengthens its hydrophobic tail regions2. Carbohydrates create recognition patterns for cells and organisms3. Cytoskeleton gives structureV. Molecules cross the plasma membrane in several waysA. Passive transport: DOES NOT REQUIRE ENERGY1. Diffusion: movement of molecules from areas of high concentration to areas of lower concentration in solutesa) Moves down a gradientb) Once equilibrium is reached, there is still movement of molecules, but movement is even between both sides2. Osmosis: diffusion of water from areas of low solute concentration to areas of high concentrationa) Moves up a gradientb) Osmotic pressure: fluid pressure required to exactly oppose osmosis3. Passive transport moves with the concentration gradienta) Facilitated diffusion: transport protein changes shape and transports molecule through the bilayerb) Small uncharged nonpolar molecules go directly through the lipid bilayerc) Diffusion through protein channels- some always open, others are “gated”B. Active Transport: REQUIRES ENERGY1. Moves substances from low concentration to higher concentration2. Requires membrane protein (transporter)3. Requires ATP and another energy sourceC. Bulk transport: used to move larger molecules1. Endocytosis: brings substances into the cell2. Exocytosis: expels substances from the cell3. Can be randomly or specifically drivenD. Info can be transferred across the plasma membrane1. Receptor proteins: receive message on receptor sites2. Different cells have different receptor proteinsVI. Isotonic extracellular fluid also maintains cell volumeA. Tonicity: relative concentration of solutes in two fluidsB. Isotonic: extracellular and intracellular solute concentrations are equal1. Hypertonic: more solute outside cell; water will leave cell and possibly shrink and die2. Hypotonic: less solute outside cell water will enter cell and possibly swell and explode3. Water will move to balance the outside and inside of cell (generally)VII. OrganellesA. Nucleus1. Information center for cell2. Contains DNAB. Ribosomes1. Free floating or bound to the rough ER2. Make proteinsC. Endoplasmic reticulum1. Rough ER has ribosomes on the surface and manufactures proteins2. Smooth ER has no ribosomes and packages proteins and lipids for delivery to Golgi apparatusD. Golgi1. 3 “S”s: sort, store, ship2. 4 types of vesicles (we need to know 2)a) Peroxisomes (digests peroxides)b) Lysosomes(1) Contain digestive enzymes for every macromolecule and digests other cells(2) Tay-Sachs disease= malfunctioning lysosomes (retains waste)E. Mitochondria1. Provides energy to the cell2. Makes ATP3. Site of cellular