I. Life’s MoleculesCarbs – sugars, starches, cellulose3 types:monosaccharides - simple sugars of 3 to 6 carbonsglucose (blood sugar)frutctose (fruit)ribose (nucleic acids)disaccharides - composed of 2 monosaccharidessucrose (table sugar)maltase (two glucose)lactose (milk)polysaccharides – many long chains of monosacch.Starch (energy storage)Cellulose (plant cell walls – wood, paper, cloth)Functions:Energy storage (in C-H bonds)For structure in plants (cellulose for cell wall)Carbon sources to make other molecules such as amino acids and nucleic acidsLipids – fats, oils, waxes, phospholipids, steroidsComposed of C, O, H atomsFats and oils made from 2 building blocks:Glycerol molecule + fatty acids = fats and oilsFats = solidOils = liquidDO NOT DISSOLVE IN WATERPhosholipids contain phosphorusHydrolipic head, hydrophobic tailThe membranes of cells is a lipid bilayerFunctions:High-energy foodPart of cell membraneAs waxes, hormones, vitamins, pigmentsEnergy storage of lipidsMonoglycerides (glycerol + 1 fatty acid chain)Diglycerides (monoglyceride + 2nd fatty acid chain)Triglycerides (digylceride + 3rd fatty acid chainHighest energy!Proteins – composed of amino acidsLarge complex moleculesComposed of C, H, O, S, and NBuolding blocks are amino acids (20)Functions:Building blocks of cellsTransport – help control what passes through plasma membraneAnimal structure (hair, nails, tendons, muscles)Enzymes – to speed up chemical reactionsNucleic acids – DNA, RNAAll are carbon-basedFormed from a few elements – C, H, O, P, NModular construction (like bricks)Function depends on structureLarge organic moleculesBasic unit is a nucleotide:SugarPhospateNitrogenous baseLong chains of nucleotidesDNA – deoxyribonucleic acid, carries info about the cellRNA – ribonucleic acid, copy of DNAATP – nucleotide compound which has role of energy transfer/exchangeFunctions of nucleotides:Info storage – like blueprint for a cell (DNA, RNA)Energy carrier (ATP)II. The CellBasic building block of living organisms that forms tissues and organsFunctionally independentUses sugars to get energy/stay aliveContains all necessary info to replicateDiscovered by Robert Hooke 1665Cell theory:Cell is the basic unit of lifeOrganisms are composed of cellsCells arise from other cells2 types of cells:1. Prokaryotic – simple cells, lack organelles; ex: bacteriaolder, smaller, no organelles2. Eukaryotic – have organelles: nuclei, mitoch, etc. many multicellular organisms are eukaryotic; ex: plant/animal cells, fungi, algae, amoebayounger, bigger, have organellesPlant Cell vs. Animal CellsPlants have: cell walls, choloroplasts, plasmodesmata while animal cells don’tPlant cells can potentially function independentCell wallProtects and supports cellMade of celluloseAllows water and other molecules to pass throughPrimary vs. Secondary cell wallPrimary – formed early, located on outermost layerSecondary – deposited on the inside between primary and plasma membraneMiddle lamella – what ‘glues’ adjacent cells togetherPlasmodesmataCytoplasmic connections between adjacent cellsAllow for the movement of materials from cell to cellCell membrane (plasma membrane)Lipid bi-layer; hydrophilic “heads” outer, hydrophobic “tails” insideDifferentially permeableLets water pass through, but not other moleculesFluid Mosaic ModelDouble layer of phospholipids with scattered proteinsInside the plant cellCytosol – matrix of water (90%), proteins, organic molecules, ionsCytoplasm – cytosol and organelles onlyProtoplast – all of the plant cell enclosed by the cell wall (plasma membrane, cytosol, organelles)CytoskeletionMicrotubles and microfilaments: make up the cytoskeleton, a network of protein cables that provide structure to the cellThey help in cell division and elongationImportant for mitosis (cell division)Plant Cell OrganellesMembrane-bound sub-compartments within the cellEach has it’s own functionNucleus – contains all genetic info (DNA) in chromosomes (DNA & proteins); nucleolus (bodies where ribosomes are made)Mitochondria – provides energy to cell by converting sugars into chemical energy (respiration); “powerhouse of the cell”Chloroplasts – site for photosynthesis; produce sugars from carbon dioxide, water, and sunlightContain chlorophyll which makes the plant greenVacuole – stores a watery solution of sugars, salts, acids, proteins; makes up 90% of plant cell volume; makes cell turgid; has it’s own membrane called tonoplast; often acidic contents – What make lemons and limes tart!Ribosomes – site for protein synthesis; use info contained in DNA to produce proteins; not membrane boundEndoplasmic Reticulum – a network of folded membranes throughout the cytoplasmSmoother – lacks ribosomes, used for packaging and transport of proteins, also to make lipidsRough – has ribosomes for protein synthesisGolgi apparatus – a stack of flattened, hollow, membranous sacs; packages these materials in vesicles to the plasma membrane; UPS of the cellEndosymbiont TheoryHow did eukaryotic organisms evolve?How did chloroplasts and mitochondria evolveChloroplasts and mitochondria:Same size as bacteriaHave their own DNADivide similarlyAre descendants of once free-living prokaryotes that were engulfed by larger cells establishing a symbiotic relationship (mutually beneficial)Lecture 3: Plant Anatomy and PhysiologyPlant Anatomy – study of the structure of organismsPlant physiology – study of the function of cells, tissues, organs of living things, and the physical/chemistry of these functionsCellsAtoms > molecules > cells > tissues > organs > whole plantTissue TypesDermal – outermost layerEpidermis – outermost layer of cells; in stems and leaves, epidermis has cuticle, a waxy layer that prevents water lossSome have trichome hairsRoot epidermis has root hairs for water/nutrient supportVascular – conducting tissue, transportTransports water and organic materialsXylem transports water and dissolved ions from the root to the stem and leaves; dead; only have cell wallTracheids – long, thin tube like structures without perforations at the endsVessel elements – short, wide tubes perforated at the ends (together form a pipe, called vessel)Both have pits (thin sections) on the wallsPhloem – carries dissolved sugars from leaves to rest of plantAlive, lack nucleus and organellesComposed of cells called sieve tube members (STM); companion cells join STN and help load materialsEnd