CHEMICAL LEVEL OF ORGANIZATION

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 + H2O → 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 +H2O

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 7.35-7.45

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 (--NH2) 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

Characteristic RNA DNA

Sugar Ribose Deoxyribose

Nitrogenous Bases Adenine, Guanine, Cytosine, Uracil

Adenine, Guanine, Cytosine, Thymine

Shape of Molecule Single strand Double stranded; double helix

Function Performs protein synthesis as directed by DNA

Stores genetic information that controls protein synthesis