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IUB BIOL-L 112 - Exam 1 Study Guide

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THERE ARE FOUR TYPES OF MACROMOLECULESCarbohydratesLipidsProteinsNucleic AcidsCHEMISTRY OF LIFEPolymers are made from many monomers through condensationDehydration reaction = building of larger moleculesOne molecule of water removed when monomer is added onto a polymerCARBOHYDRATESInclude simple sugars (glucose, fructose) and polymers of sugars (glycogen), starch (storage in animals), cellulose (plants)In animals, carbs are a primary source of:Dietary energy – cellular respiration = 32 ATP’sStorage energy – animals – glycogen – glucoseIn plants carbs serve as:Building materialSTRUCTURE AND FUNCTIONCarbon 1 and 4(Pointing down=Alpha – Starch) (Pointing up=Beta – Cellulose)FATSPerform essential functions in the human body:Energy storageCushioningInsulationHormones – SteroidsSTRUCTUREWhen the “tail” of the molecule can bend it is unsaturatedTypical triglyceride consists of:A glycerol molecule (Hydrophilic head)Joined with three fatty acid molecules (hydrophobic tail) via the dehydration reactionTYPES OF FATSSaturated: Stiff unhealthy (animal fat etc.)If the carbon skeleton of a fatty acid has the maximum number of hydrogen it is saturatedUnsaturated: Liquid, Healthier (olive oil etc.)If the carbon skeleton of a fatty acid has fewer than the maximum number of hydrogen molecules, it is unsaturatedTrans FatHydrogenationAdds hydrogen and converts unsaturated fats to saturated fats. It makes liquid fats solid at room temperature, and creates trans fat, a type of saturated fat that is particularly bad for your health. Unsaturated fat with more hydrogen molecules to give it a smooth texture (Margarine, donuts etc.)Fat as hormones/steroidsSteroids are very different from fats in structure and function.The carbon skeleton is bent to form four fused rings. Steroids vary in the functional groups attached to this set of rings, and these chemical variations affect their function.Synthetic anabolic steroidsAre variants of testosterone and mimic some of its effects. They can cause serious physical and mental problemsMay be prescribed for some cancersPROTEINSBuilding blocks of proteins: Amino Acids (Generally 20 amino acids)Each amino acid consists of a central carbon atom bonded to four covalent partnersThese attachment groups are common to all amino acids:A carboxyl group (-COOH)An amino group (-NH2)A hydrogen atomA unique R groupTo make a polymer attach the OH of the carboxyl group and the H of the aminogroup removing them through the dehydration reactionAverage size of a protein molecule: 300 amino acidsProtein functions are influenced by there three-dimensional structure. They have tobe folded in a very specific wayPrimary Structure: Unique sequence of amino acids arranged in a long chainSecondary Structure: Affected by pattern of hydrogen bonds between amino acids in a long chain. When it starts folding (Slinky)Alfa helix and B pleated sheetsTertiary Structure: Dictated by primary and secondary structure. Folding leading to 3D shape (Globules shape)Quaternary Structure: Made up of several polypeptide chains that must fit together to form functional protein. Four Tertiary structures are put together. (ex. Hemoglobin)Denaturation: When an unfavorable change in temperature and/or PH, it canunravel the protein and cause it to lose its shape. (High fever above 104F)Enzymes (E)Protein molecules that act as catalystsReact with specific substances called substrates (S)3D structure of active site is critical to binding of E to SInhibitors – Decreases reaction rateProtein Misfolding and DiseaseMisfolded proteins are associated with for:Alzheimer’sMad CowParkinson’sSickle cell anemiaCystic fibrosisProteins go into a “Cage” and a Chaperonin or “lid” will seal it in to protect the protein while it folds then it is releasedNUCLEIC ACIDSFunction: Information storage (DNA and RNA)A gene is a specific stretch of DNA that programs the amino acid sequence of aPolypeptide.The chemical code of DNA must be translated from “nucleic acid language” to“Protein language”This is done through the RNA.Nucleic Acids are polymers made from monomers called nucleotidesEach nucleotide has three partsA five-carbon sugarA phosphate groupNitrogen – containing base (A, G, C, T)Dehydration reactions link nucleotide monomers into long chains calledpolynucleotides. They form covalent bonds between the sugars of one nucleotideand the phosphate of the next and form sugar-phosphate backbones.MICROSCOPYMicroscopy provides enlargement and resolutionLight MicroscopeEnlargement provided by objective lens and ocular glass and lensesIllumination provided by lightTransmission Electron Microscope (TEM)Illumination provided by electron beam – much shorter wavelengthVery high resolutionScanning Electron Microscope (SEM)Electrons do not pass through specimenLower resolution than TEM3D imageTWO MAJOR CATEGORIES OF CELLSProkaryotic cells – Bacteria and ArchaeaSimple smallerEukaryotic Cells – protists, plants, fungi and animalsCytoskeleton – microtubules, intermediate filaments, microfilamentsPLASMA MEMBRANEA Fluid Mosaic of Lipids and ProteinsMembranes composed mostly ofLipids - The lipids are phospholipids (phospholipid bilayer)Proteins – Regulate traffic across the membranes and perform other functions.Plasma membrane is a fluid mosaicFluid – Molecules move freely past one anotherMosaic – Diversity of proteins in the membraneNUCLEUSNuclear envelope: Double membrane separating nucleus andcytoplasmPores: Allows material to move between the nucleus and cytoplasm selectivelyNucleolus: In nucleus where ribosome precursors are assembled (rRNA and rProteins)Chromatin: DNA molecules and associated proteins that form fibersNucleosome: Unit of DNA packing (DNA wraps around 4 pairs of histone)Each long Chromatin fiber constitutes one chromosomeThe number of chromosomes in a cell depends on the speciesRIBOSOMESProtein making machines of the cellPartially assembled in the nucleolus and totally in the cytoplasmHOW DNA DIRECTS PROTEIN PRODUCTIONDNA programs protein production in the cytoplasm by transferring its coded information into messenger RNA (mRNA)Messenger RNA exits the nucleus through pores in the nuclear envelopesA ribosome moves along the mRNA, translating the genetic message into a protein with a specific amino acid sequence.ROUGH ERRibosomes that stud the outside of the portion of the ER membrane make the ER “rough”. Produce membrane proteins and secretory proteinsSome products


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