August 30, 2022CHAPTER 2: CHEMICAL COMPONENTS OF CELLSMain Chemical Groups Commonly Found in Biological Molecules- Methyl -CH3 Nonpolar hydrocarbon- Hydroxyl -OH Alcohols- Carboxyl -COOH Weak acid- Carbonyl C=Oo Ketone Internal carbono Aldehyde Terminal carbon- Amino -NH2 Weak base- Amide -O=C-NH2 Carboxyl + amine- Phosphate -PO3 Ester and anhydrides- Sulfhydryl -SH Forms disulfide bondsCompoundsC-H Compounds:-Make hydrocarbons-Nonpolar-Do not form hydrogen bonds-Generally insoluble in waterC-O Compounds:-Covalently bonded -Examples-Alcohol: The -OH is called a hydroxyl group-Aldehyde: The C=O is called a carbonyl group-Carboxylic Acid: The -COOH is called a carboxyl group (In water, it loses an H+ ion to become -COO-)-Esters: Formed by combining an acid and an alcoholC-N Compounds:-Amines: In water combine with an H+ ion to become + charged-Amides: Formed by combining an acid and an amine. They are uncharged in water (Example is the peptide bond that joins amino acids in a protein)-Nitrogen occurs in several ringsPhosphatesAugust 30, 20224 Major Classes of Biological Molecules-Polysaccharides-Fatty Acids-Proteins -Nucleic AcidsSugars and Polysaccharides-Sugars are monosaccharides -Have the general formula CH2O-Are carbohydrates-Most important in terms of structure and energy are 6 carbon sugars-Most important is Glucose!!!Glucose:-Anything you eat eventually gets converted to glucose to generate energy-Glucose isn’t always a ring; it can convert to a linear structure-When you go from a linear to a ring, it all depends on the bond as to whether or not you generate Beta glucose or alpha glucoseAnabolism (making macromolecules):-Taking water out-CondensationCatabolic:-Bringing water in-HydrolysisAugust 30, 2022Polysaccharides:-Made by plants-Example why type of linkage and orientation is important -Alpha Glucose keeps the same orientation to make a 1-4 linkage to make starch-Beta Glucose flips its orientation every other molecule to make a 1-4 linkage which makes CelluloseFatty Acids and Lipids-Insoluble in water-Lipids or fats are not polymers of fatty acids, but are formed by condensation reactions -Functions:-Structural: Cell membranes-Energy storage: TriacylglycerolsFatty Acids-Long, unbranched hydrocarbon chains with single carboxyl group on the end -Amphipathic molecules: Hydrophilic end (carboxyl) and hydrophobic end (hydrocarbon)-Typically an even number of carbons-In water, they can form a surface film or form small micelles (an enclosed structure)-Triacylglycerol (fat molecule):-The linkage between fatty acids and glycerol-This is a condensation reaction-Forming an ester bond-Every carbon is connected to 2 hydrogens and 1 carbon (that’s what saturated means)-Unsaturated fatty acids have cis double bonds which cause bending (whereas saturatedfatty acids are straight and stuck together)August 30, 2022-If these molecules have unsaturated fatty acids they take up more space because those fatty acids want to bond to each other due to a hydrophobic force, but they can’t bond because of the bending from double bonds-Trans fats have a double bond every other carbon (trans fats will clog your arteries)Desaturation Changes Fat Properties-Saturated fat and fatty acids are solid at room temperature-Unsaturated fat and fatty acids are liquid at room temperaturePhospholipids-Similar to triacylglycerols -Glycerol + 2 fatty acids + phosphate group linked to another hydrophilic molecule-Highly amphipathic - “Hydrophilic Head” is polar- “Hydrophobic Tail” is nonpolar-Membrane structural componentsAmino Acids and Proteins-Proteins are polymers of amino acids-Formed by condensation reactions-Large macromolecules, diverse shapes-Functions:-Enzymatic-Signaling-Structural Amino Acids-Monomer subunit of proteins-20 different amino acids re found in proteins-All have amino- and carboxyl- groups-Functionality derives from side groups:-Acidic or basic-Polar or nonpolar-Other featuresAugust 30, 2022Amino Acid Side Chains (R-groups)-Classified as:-Nonpolar (hydrophobic)-Glycine-Alanine-Valine-Leucine-Isoleucine-Methionine-Phenylalanine-Tryptophan-Proline-Charged (acidic)-Aspartic acid-Glutamic acid -Charged (basic)-Lysine-Arginine-Histidine-Uncharged polar (hydrophilic)-Asparagine-Glutamine-Serine *be able to draw*-Threonine-Tyrosine-Cysteine-Nonpolar and can form disulfide bonds (these can form between two cysteine side chains)Peptide Bonds-Amide linkage that joins Amino acids together (joins together the amino group and carboxyl group)-Condensation reaction* Be able to draw*Nucleotides and Nucleic Acids-Nucleic acids (DNA and RNA) are polymers of nucleotides-Formed by condensation reactions-Functions:-Nucleotides function as energy carriers- Nucleotides function as signaling moleculesAugust 30, 2022-DNA and RNA function to store and transmit (express) genetic info-ATP: A primary energy storage molecule that can also be incorporated into RNAStructure:-Nucleotide = base + pentose + phosphate-Nucleoside = base + pentose-Nitrogenous Bases:-Pyrimidines: Cytosine, Thymine (in DNA), Uracil (in RNA)-Purines: Adenine, Guanine-Pentose Sugars: -Deoxyribose (in DNA)-Ribose (in RNA)-Nucleotides are joined together by a phosphodiester linkage to form nucleic acids-This is a condensation reaction-Nucleic acids have structural polarity-Structural polarity: The 5’ end has a free phosphate group, the 3’ end has a free hydroxyl groupDNA-Sugar-phosphate backbone-Hydrogen-bonded base pairsComplementary Base Pairs *recognize by their structure-A base pairs with T or U (in RNA)-2 hydrogen bonds-Less stable than G:C base pairs-G base pairs with C-3 hydrogen bonds-More stable than A:T base pairs-Guanine has three groups that can form hydrogen bonds*In order to recognize them by their structures, Look at which ones can base pair with each