Water, pH, and Biological Molecules 9/22/2018 Water, pH and Biological Molecules What’s so special about water? It’s a great solvent. It hold’s tons of heat. It has high surface tension. Its less dense as a solid than a liquid. G. Podgorski, Biol. 1010

WATER H20 POLAR UNEVEN ELECTRICAL CHARGE- COMPOUND=== Area by oxygen slight neg. charge Area by hydrogen slight pos. charge

Water, pH, and Biological Molecules 9/22/2018 For Polar Molecules, Water Is a Wonderful Solvent Dissolving table salt (sodium chloride) Ionic compounds dissociate or break apart into ions. In biological processes Na ions are necessary for reactions to occur G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Water Holds Immense Amounts of Heat High thermal capacity COHESION-when one molecule of water is attracted to another water molecule by hydrogen bonds ** due to hydrogen atoms positive charge attracting to Negitively charged oxygen on another water G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Water Has High Surface Tension Cohesion allows water to be pulled up To leaves ( Capillary action) High surface tension allows long water columns to be drawn from roots to leaves – even in a redwood. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Water Is Lighter as Solid than as a Liquid This means that ice forms an insulating blanket over water. G. Podgorski, Biol. 1010

DISSOCIATION OF WATER In pure water no. of hydronium ions To hydroxide ions are equal (neutral)

Acid/ base/neutral Acidic solution- when a substance dissolves in water forms hydronium ions and results in more hydronium than hydroxide ions Basic- more hydroxide Neutral – equal

Water, pH, and Biological Molecules 9/22/2018 pH Matters pH scale 1 to 14 G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Acids and Bases An acid produces H+ A base absorbs H+ G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Carbon’s Cool Carbon is the central atom of life. Because carbon contains 4 electrons in its outer shell, it can pair in many ways with many different atoms in an “attempt” to fill its outer shell. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Carbon is the Central Atom of Life. glucose amino acids fat G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Some Useful Nomenclature Learn to recognize these chemical groups. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 In Biology, Molecular Shape Matters Its not just chemical formula, it’s the shape of the molecule that lets it do its “job”. Never forget the axiom – structure dictates function. Some major types of biological molecules. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Molecules of Life How do you build a cell? Start with water, add lots of small carbon-containing molecules and ……. use these four major classes of biological molecules. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Monomers, Polymers and Macromolecules Many biological molecules are macromolecules – huge assemblies of atoms. Biological macromolecules are formed by linking together a set of building blocks (monomers) into long chains (a polymer). G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules Carbohydrates 9/22/2018 Carbohydrates are used for energy and to create structures. The building blocks for carbohydrates are simple sugars. Three views of glucose, a common simple sugar. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Linking Simple Sugars – the First Step to a Polymer monosaccharides a disaccharide A complex carbohydrate is a long-chain polymer made of simple sugars. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Some Familiar and Important Complex Carbohydrates Note the way complex macromolecule are built by linking simple repeating units. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Carbohydrates are Central Players in Energy Production and Storage G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Complex Carbohydrates Are Often Used to Create Structures Cellulose is the most abundant macromolecule on earth – and you’re probably wearing it now. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Lipids are Hydrophobic Molecules That Exist In Three Primary Forms Fat Sterol Phospholipid G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Space-filling model of a fat Fats Are Made By Linking Fatty Acid Chains to Glycerol, a Three Carbon Molecule A fatty acid G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Molecular Structure of a Fat Figure: 03-15 Title: The Triglyceride Tristearin Caption: This lipid molecule is composed of three stearic fatty acids, stemming rightward from the glycerol OH “heads.” Tristearin is found both in beef fat and in the cocoa butter that helps make up chocolate. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Fats are Used in Energy Storage and Production G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 The Degree Of Saturation In A Fat Affects Its Physical And Health Properties Where are the double bonds? G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 all cis polyunsaturated Cis and Trans Unsaturated Fats “Good” Omega-3-fatty acids mono- and poly-unsaturated saturated trans “Bad” G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 At a Store Near You The new line showing levels of trans fat Beginning January 1, 2006, the FDA required that the amount of trans fat be listed on all food labels. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Sterols Note the four ring structure common to all sterols. Sterols are: 1) essential membrane components and 2) form many hormones. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Sterols As Hormones Estrogen, testosterone, progesterone, and corticosteriods (cortisol) are all steroid hormones. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Sterols As Hormones A heavily muscled Linford Christie who was disqualified from international competition after testing positive for a banned steroid. “Designer steroids” are major sporting news where they have been used illegally in track and field, baseball, football and countless other sports. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Phospholipids are Building Blocks of Cellular Membranes The hydrophilic head group and hydrophobic tails are the keys to phospholipid function. Phospholipids have a molecular Jekyll and Hyde split personality. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Hydrophilic Head Group And Hydrophobic Tails Are The Keys To Phospholipid Function G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Phospholipids Form Double-Layered Biological Membranes G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Protein Proteins are THE key elements of life. Forget DNA, proteins rule. Remember the principle - structure determines function. Since proteins are the key players of the cell, it follows that protein structure determines cell function. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Some of the Diverse Functions of Proteins G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Strands of the Protein Keratin Create Hair G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Proteins are Linear Chains of Linked Amino Acids G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 A Common Thread and a Unique Identity G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Amino Acids, Peptide Bonds, Polypeptides, Protein Peptide bonds Proteins are linear chains of 20 different building blocks called amino acids. Amino acids are linked by peptide bonds – a form of covalent bond. G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Proteins are Folded Structures Whose Shape (and therefore function) Depends on Amino Acid Sequence G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Nucleic Acids There are two kinds of nucleic acids, DNA and RNA. Both are involved in the storage and flow of information from gene to gene product. Recently, we’ve learned that RNA also plays important regulatory roles. DNA G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Nucleotides Are the Monomers That Create Polymers of DNA and RNA G. Podgorski, Biol. 1010

Water, pH, and Biological Molecules 9/22/2018 Nucleotides are Important in Their Own Right ATP, the cell’s primary energy currency. Nucleotides fuel the cell and coordinate its metabolism. G. Podgorski, Biol. 1010