BIOLOGY 151 Edition Lecture 3 Outline of Last Lecture I. CarbsII. LipidsIII. ProteinsOutline of Current Lecture - Nucleic acids- The cell theory- Biological Membranes –Structureo Major components (95%) Phospholipids, proteins Models of organizationo Minor components (5%) Glycoproteins and glycolipids (cell identify markers) Sterols (fluidity buffers)Current Lecture- Nucleic acids: (made of nucleotides)o Important polymers: DNA and RNA Subunits= monomers called nucleotides, has 3 parts- Phosphate group: can have between 1-3- Pentose (5C) Sugars: ribose (RNA) or deoxyribose (DNA)- Nitrogenous base: 4 in RNA, 4 in DNA ATP (a nucleotide): ribose based, adenine is the nitrogenous base, hydrophilic phosphate group  overall hydrophilic- Life as we know it starts in water (aqueous based) o Goes from chaos, disorder to order where life can existso Needs:  Physical boundary (membrane), information, work/energy- Cell theory of life: (theory=formal presentation of life as we know, backed by scientific evidence)o Cell is the functional unit of life All living organisms are composed of one or more cellsThese 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.o Cells arise only from preexisting cells by dividingo Disorder isn’t life order is life- Physical Boundary: cytoplasm within plasma membrane (aka plasmalemma); organelles surrounded by cytosol.o Boundary that separates hydrophobic from hydrophilico Monolayer of phospholipids vs. phospholipid bilayer- “sealed spheres” are stable formo Can be very large (eukaryotic cell): 10-100 μm in diameter μm=micrometer=10^-6mo Can be medium (prokaryotic cell, large organelle): 1μm in diametero Can be small (vesicle): 50-60nm in diameter 1nm=10^-9m- Biological Membrane:o Made up of 1) phospholipid bilayer and 2) associated protein (makes up 95% of membrane by masso Two models Old model: predicts protein is hydrophilic, which is false; predicts smooth cut Fluid Mosaic Model: predicts “chunks”- 2 classes of proteins: 1) peripheral proteins: associated with surface 2) integral membrane proteins: imbedded in phospholipid bilayer; has van der Waal interactions, but not bonded, so not held in space- How to test two models: o Freeze Fracture: reveals “chunky peanut butter”- Minor components:o Glycoproteins (sugar component) and glycolipids: these molecules will carry sugar tags as identity markers Sugars are small and simple ei. Blood type (A, B, AB, O) depends on glycolipids in Red Blood Cellso Sterols (cholesterol): cholesterol is only in animal cells, but plant cells have othersterols Cholesterol is very hydrophobic; important in membrane