Science 10

Chemistry of Life Hydrogen Oxygen Carbon Gold Silver Element - any substance that is comprised of one type of atom and cannot be broken down into another substance. Examples Hydrogen Oxygen Carbon Gold Silver http://facstaff.gpc.edu/~pgore/PhysicalScience/periodic-table.gif

Chemical Bonds http://kentsimmons.uwinnipeg.ca/cm1504/Image57.gif Ionic bonds - formed through the transfer of electrons between two atoms. The bond is due to the attraction of oppositely charged ions (atoms with a negative or positive charge).

Chemical Bonds http://cache.eb.com/eb/image?id=96904&rendTypeId=4 Covalent bonds - formed through the sharing of atoms between atoms.

Mixture - a substance composed of two or more elements or compounds which are physically mixed together, but not chemically combined. http://topshelfsweetsngifts.com/Deluxe%20Mixture%20Website%20Photo%2010-20-05.jpg

Solute - substance that is dissolved. Solution - mixture of two or more substances in which the substances are evenly distributed. http://intro.chem.okstate.edu/ChemSource/Solutions/image3QT.JPG Solute - substance that is dissolved. Solvent - substance in which the solute is dissolved.

Can it be physically separated? Matter Flow Chart MATTER yes no Can it be physically separated? MIXTURE PURE SUBSTANCE Is the composition uniform? no yes Can it be chemically decomposed? no yes Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element Colloids Suspensions

Water is the solvent of life

Chemical elements and water Elements of life (most common) Carbon, hydrogen, oxygen Other necessary elements & function Nitrogen (amino acids), Calcium (bones, teeth), Phosphorous (ATP, DNA), Iron (hemoglobin), Sodium (nerve transmision)

Like no other common substance, water exists in nature in all three physical states: as a solid as a liquid as a gas

Properties of water Transparency: Cohesion: Light can easily pass through Reach inside cytoplasm (water) to chloroplast, retina Reach organisms in water Cohesion: Water molecules stick together (surface) Water can be pulled up trees Small animals can live on water surface (mosquito)

Properties of water Solvent Properties (universal solvent) Allow substance carried in water blood, sap Thermal properties (large heat capacity) requires large amounts of energy to heat remains stable temperature fish, blood (carry heat to cold parts)

Properties of water Thermal properties (cooling from evaporation) evaporate at temperatures below boiling heat energy required to break hydrogen bonds, taken from liquid water cooling it down

Hydrophobic Hydrophilic Properties of Water http://dl.clackamas.edu/ch104-02/images/104vol07.jpg http://asia.cnet.com/i/r/2006/dc/39304504/pearls_sc.jpg Cohesion - attraction between molecules of the same substance. Adhesion - attraction between molecules of different substances.

Cohesion: Water molecules stick together surface tension

Polarity Polar: Uneven distribution of charge within the molecule. Example: H2O (water) Non-polar: Even distribution of charge within the molecule. Example: BF3 (boron trifluoride) Like dissolves like Something polar dissolves something polar Something nonpolar dissolves something nonpolar

Polar molecules are also soluble in water because they can also form hydrogen bonds with water. Even large molecules, like proteins, can dissolve in water if they have ionic and polar regions. Fig. 3.8 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 3.7 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Biochemistry The chemistry of Life Bio-molecules Proteins Carbohydrates Lipids (fats, membranes…) Nucleic Acids (DNA…)

Trace elements May be needed in only small amounts but may cause goiter May be needed in only small amounts but may cause harm if absent (iodine)

Organic Compounds Contain carbon & found in living organisms Inorganic Carbon compounds: CO2, Many inorganics found in living organisms Iron in blood

Macromolecules - large molecules formed through the joining of many monomers (small molecular units) into polymers (larger molecules). http://hsc.csu.edu.au/senior_science/options/polymers/2973/images/Fig_9513.jpg We will be studying 4 important macromolecules: Carbohydrates, lipids, proteins, nucleic acids. http://chemistry2.csudh.edu/rpendarvis/1feb23.gif

Monosaccharides - single sugar molecules (glucose, galactose). Carbohydrates - sugars which contain C, H and O and are the main energy source for all living things (some organisms also use carbohydrates for structural purposes). Monosaccharides - single sugar molecules (glucose, galactose). Disaccharides - carbohydrates composed of two sugar molecules (lactose). Polysaccharides - large carbohydrates composed of many monosaccharide monomers (starch, cellulose, glycogen). http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch25/b-d-glucose06.gif http://dspace.dial.pipex.com/town/park/gfm11/nomilkgif/LACTOSE.JPG http://bioweb.wku.edu/courses/BIOL115/Wyatt/Biochem/Carbos/Carb_poly.gif

Condensation Reaction: monomers form chains Remove water to form bonds Protein synthesis Fatty acid synthesis 1 2 3 Short polymer Unlinked monomer Removal of water molecule 1 2 3 4 Longer polymer Figure 3.3A

Hydrolysis - reverse process of condensation polymers are broken down to monomers Using water 1 2 3 4 Addition of water molecule 1 2 3

Carbohydrate Polymers Monomer: Monosacccharide Glucose – the most basic unit of sugar (energy) The building block Polysaccharides: Glycogen: energy storage Animal muscles Starch: plant energy storage Cellulose: plant structure

The structure of glucose

Starch: plant energy storage Cellulose: plant structure A polysaccharide is made by linking two (or more) monosaccharides together. Glycogen: energy storage animal muscles Starch: plant energy storage Cellulose: plant structure glucose + fructose = sucrose glucose + galactose = lactose

Functions of Lipids (fats) A group of organic compounds, including fats oils, and waxes that are soluble insoluble in water. Energy storage: Insulation: Protection: Membranes (phospholipids):

Glycerol & fatty acid

Proteins - macromolecules that contain N, H, O and C Proteins - macromolecules that contain N, H, O and C. Are comprised of amino acid (the order and combination of these amino acids determines the role of the protein) subunits. Types of proteins: Enzymes - carry out the chemical reactions in the organism (lactase, DNA helicase, catalase). Structural Proteins - aid in building muscles, bones and other components of the organism (keratin, collagen). Functional Proteins - assist in organism’s daily functioning such as messengers (hemoglobin, insulin), defense or transport. http://www.tikirobot.net/wp/wp-content/uploads/2007/11/0143.gif http://www.wellesley.edu/Chemistry/chem227/structproteins/stash.jpg http://www.olives101.com/wp-content/uploads/img182.imageshack.us/img182/8476/20060928t113722z01nootrrtridsp2oukoeukguinnessfe6.jpg

Dehydration synthesis Protein Synthesis amino acids link dipeptides polypeptide chains (Proteins) The bonds are called peptide bonds Dehydration synthesis Figure 3.13

Proteins have levels of organization. Proteins can be denatured. Primary structure refers to the sequence of amino acids joined by peptide bonds. Secondary structure is any folding or twisting of the chain in space. Tertiary structure comes about when proteins fold into globular shapes. Quaternary structure occurs in proteins that have more than one polypeptide chain twisted together. Extremes in temperature or pH, or chemicals, radiation, and so forth can cause proteins to unfold, thus denaturing them.

Enzymes Enzyme Active Site Protein Biological catalyst Example: amylase Active Site Location where substrate (reactant) binds

Lock and Key Model (enzyme-substrate specificity)

Effects of variables on enzymes Temperature pH

Nucleic Acids - macromolecules that contain H, O, N, C and P Nucleic Acids - macromolecules that contain H, O, N, C and P. The 2 kinds of nucleic acids are DNA and RNA which store and transmit genetic information (the “blueprint” to make you). http://www.scfbio-iitd.res.in/image/nucleotide.jpg http://faculty.uca.edu/~johnc/RNA%20DNA.gif Comprised of nucleotide (5-C sugar, phosphate group and nitrogenous base) monomers.