Advance Biology Fall 2012

Vocab development  Anabole- a building up  Di- two  Endo- inside  Exo- outside  Glyco- sugar  Hydro- water  Katabole- a throwing down   Katalysis-dissolution  Lipos- fat  -lysis- a loosening  Metabole- change  Mono- single  Poly- many  Sakcharon- sugar

Atoms  Atoms are the basic particles of matter  Consist of:  Protons (+)  Neutrons (n)  Electrons (-)

Elements  Consists entirely of atoms with the same of protons and neutrons in its nucleus  Exception to this is an isotope  mass number- total number of protons and neutrons in the nucleus  Atomic weight- takes into account the mass of the subatomic particles and the relative proportions of any isotopes  Atomic number- number of protons in an atom of an element

Chemical Bonds  Chemical bonds are forces formed by atom interactions  Chemical bonds produce :  Molecules– contain more than one atom bonded together by shared electrons (covalent bond)  Compounds- made up of two or more atoms or elements (ionic or covalent bond)

Chemical Bonds  Ionic bonds  Results from the attraction between ions  Ions- atoms or molecules that have an electric charge  Cations- positive ions  Anions- negative ions

Chemical Bonds cont…  Covalent Bonds  Result from the sharing of electrons  Sharing one pair of electrons is a single covalent bond  Sharing two pairs of electrons is a double covalent bond

Chemical Bonds cont…  Covalent bonds cont…  Non-polar covalent bond  Help form most of the framework of the large molecules in the human body  Polar covalent bonds  Unequal sharing of electrons

Chemical Bonds cont…  Hydrogen bonds  Attraction between a slight positive charge on a hydrogen atom and a weak negative charge on an oxygen or nitrogen of another polar molecule

Chemical Reactions  Chemical reaction- new bonds form between atoms or existing bonds between atoms are broken  Reactants- beginning substances  Products- resulting substances

Chemical Reactions cont…  Metabolism refers to all chemical reactions that take place in the body.  chemical reactions are written in chemical notation

Basic Energy Concepts  Work- movement or a change in the physical structure of matter  Energy- capacity to perform work  Kinetic energy- energy of motion  Potential energy- stored energy

3 types of reactions  Decomposition- breaks a molecule into smaller parts (AB → A + B)  Ex: digestion  Hydrolysis  A—B—C—D—E + H 2 O → A—B—C—H+HO—D—E  Catabolism- decomposition reactions that happen within cells

3 types of reactions  Synthesis – builds larger molecules from smaller components (A+B →AB)  Dehydration synthesis- A—B—C—H+HO—D—E → A—B—C—D—E +H 2 O  Anabolism- synthesis of new compounds within the body

3 types of reactions  Exchange – parts of the reacting molecules are shuffled (AB + CD → AD + CB )

3 types of reactions  Many important biology reactions are freely reversible  Two reactions occur simultaneously one decomposition one synthesis  Equilibrium – both reactions are occurring at the same rate

Enzymes  Activation energy- amount of energy needed to start a reaction  Enzymes- molecules that speed up reactions  Catalysts- compounds that accelerate chemical reactions without being permanently changed

Inorganic vs. Organic Compounds  Inorganic compounds – small molecules that generally do not contain carbon and hydrogen atoms  Organic compounds- molecules primarily composed of carbon and hydrogen atoms  Can be much larger and more complex than inorganic compounds

Inorganic & Organic  Nutrients- essential elements and molecules obtained from the diet.  Metabolites- all of the molecules that are broken down by chemical reactions within our bodies

Water!!!  Water is the single most important constituent of the body  3 general properties of water that are important to the human body  Water is an essential reactant in chemical reactions of living systems.  Water has a very high heat capacity.  Water is an excellent solvent.  Many inorganic molecules undergo ionization in water to form ions.

Body pH  The pH of a solution indicates the concentration of hydrogen ions it contains.  Acidic (pH less than 7)  Neutral (pH of 7)  Basic (pH greater than 7)  Buffers maintain pH within normal limits by releasing or absorbing hydrogen atoms  pH of blood & most body fluids is

Carbohydrates  Carbohydrate- contains carbon, hydrogen, and oxygen in a 1:2:1 ratio  Most important energy source for metabolic processes within the body.

Carbohydrates  3 major types of carbohydrates  Monosaccharides  Disaccharides  Polysaccharides

Carbohydrates  Monosaccharides  Simple sugar  Ex: glucose (most important metabolic fuel)

Carbohydrates  Disaccharides  Two monosaccharides bonded together  Ex: sucrose (table sugar), lactose (milk), maltose  Used as an energy

Carbohydrates  Polysaccharides- many monosaccharides connected  Starches – important energy source  Cellulose- plant starch  Glycogen- animal starch

Lipids  Lipids are water insoluble  Major types:  Fatty acids  Fats  Steroids  Phospholipids  Form essential structural components of all cells  Used as energy reserves

Lipids  Fatty Acids  Primary function:  Energy source  Absorbed from food or synthesized in cells  Saturated  Butter, fatty meat, ice cream  Unsaturated  Vegetable oils

Lipids  Fats  Glycerol  Fatty acids attach to this to form fats  Triglyceride  Most common fats in the body  Primary functions:  Energy source  Energy storage  Insulation  Physical protection

Lipids  Steroids  Primary functions:  Structural components of cell membranes  Hormones  All have the same carbon-ring framework.  Cholesterol  Both useful and harmful  Two sources  Food  Liver

Lipids  Phospholipids  Primary function:  Structural components of cell membranes  Most abundant component

Proteins  Formed from amino acids  Contain carbon, hydrogen, and nitrogen  Types:  Structural  Contractile  Transport  Enzymes  Antibodies

Proteins  Structural Proteins  Function: support  Create 3-d framework for the body  Provide strength, organization, and support for cells, tissues, and organs

Proteins  Contractile Proteins  Function: movement  Responsible for muscle contraction  Movement of individual cells

Proteins  Transport Proteins  Function:  Transport molecules into and out of cell  Transport molecules between parts of a cell  Transport molecules from cell to cell

Proteins  Enzymes  Function:  Metabolic regulation  Sensitivity of enzymes is important in controlling the pace and direction of metabolic operations

Proteins  Antibodies  Function:  Protect us from disease

Protein Structure  Proteins are long chains of amino acids  20 amino acids in the human body  Each amino acid has  Central carbon atom bonded to  Hydrogen atom  Amino group (--NH 2 )  Carboxylic acid group (--COOH)  Variable R group (side chain)

Protein Structure  Amino acids are linked together by peptide bonds  Peptides are molecules made up of amino acids held together by peptide bonds  Polypeptide- many peptides connected together  Greater than 100 amino acids = protein

Protein Structure  Basic structure is established by the sequence of amino acids  Characteristics of a certain protein are determined in part by the R groups on its amino acids  Shape of a protein determines is function  Denaturation- a change in the 3-D shape of a protein

Nucleic Acids  Store and process information at the molecular level inside cells  2 classes  DNA (deoxyribonucleic acid)  RNA (ribonucleic acid)

Nucleic Acid Structure  Made up of subunits called nucleotides  Nucleotides include 3 parts  Sugar  Phosphate group  Nitrogenous base  5 nitrogenous bases  Adenine  Guanine  Cytosine  Thymine (only found in DNA)  Uracil (only found in RNA)

DNA & RNA Comparison CharacteristicRNADNA SugarRiboseDeoxyribose Nitrogenous BasesAdenine, Guanine, Cytosine, Uracil Adenine, Guanine, Cytosine, Thymine Shape of MoleculeSingle strandDouble stranded; double helix FunctionPerforms protein synthesis as directed by DNA Stores genetic information that controls protein synthesis