Anatomy & Physiology I Unit Two

Definitions Basic Chemistry Matter – any thing that has mass and takes up space Therefore – all organisms as well as the visible or unseen physical world around them are made of matter

Definitions Basic Chemistry Atom – the smallest particle of an element that retains the characteristics of the element Element – a substance that cannot be changed into another substance

Atom Anatomy Electron – negative charge Neutron – neutral charge aaaaaaaaaaaaa Neutron – neutral charge Proton – positive charge

C 6 12.01 Periodic Chart Information Atomic Number (P#) Chemical Symbol Atomic Mass (P# + N#)

Atom Examples

Definitions Basic Chemistry Isotopes –atoms of an element that have varying numbers of neutrons

Definitions Basic Chemistry Molecule – a particle made up of two or more atoms bonded together Diatomic molecule– two of the same type of atom bonded together such as O2 or N2

Definitions Basic Chemistry Compound – a substance made up of two or more elements bonded together Therefore – the smallest particle of a compound that retains its characteristics is a molecule (H2O or CO2)

Definitions Basic Chemistry Ion – an atom that has given up or gained electrons to achieve stability Cation – a positively charged ion that has given up electrons Anion – a negatively charged ion that has gained electrons

Definitions Basic Chemistry Electrolytes – salts that ionize in water and form solutions capable of conducting electricity Therefore – electrolytes (ions) carry a positive or negative charge

Definitions Basic Chemistry Free radical – a chemical particle carrying an odd number of electrons (O2-) Explanation – free radicals are formed from metabolic reactions, by radiation or chemicals

Definitions Basic Chemistry Free radical – a chemical particle carrying an odd number of electrons (O2-) Explanation – free radicals quickly combine with other molecules converting them into free radicals which will destroy more molecules

Definitions Basic Chemistry Antioxidant – a chemical that neutralizes free radicals Explanation – the body produces enzymes to convert free radicals and antioxidants are obtained through the diet

Ionic Bonds Bonds formed by the attraction between ions of opposite charges

Covalent Bonds Bonds formed by the sharing of electrons between atoms

- a covalently bonded, polar molecule Water - a covalently bonded, polar molecule aaaaaaaaaaaaa Molecules are said to be polar if they have slight opposite charges on either end

The slight attraction between the negative end of one molecule and the positive end of another results in a… aaaaaaaaaaaaaaaaa

The Relative Strengths of Chemical bonds Covalent bonds The undisputed champion!!! Ionic bonds The middleweight!! The weakest! Hydrogen bonds

Definitions Basic Chemistry Acid – a compound that releases hydrogen (H+) ions in solution Base – a compound that releases hydroxide ions (OH-) in solution

Definitions Basic Chemistry Salt – an ionic compound that does not contain H+ or OH-, obtained from an acid/base reaction Buffer – a chemical system that resists large changes in pH by taking up or giving off H+

Acid-Base Reaction HCl + KOH KCl + H2O Cl- K+ H+ OH- Acid Base Salt Water HCl + KOH KCl + H2O Cl- K+ H+ OH-

Definitions Basic Chemistry pH – the measurement of the H+ concentration in a solution

pH – the measurement of the H+ concentration in solution

Buffers Remember – a buffer is a chemical system that resists large changes in pH by taking up or giving off H+ Therefore, a buffer is a homeostatic mechanism that helps to regulate the pH of blood and other body fluids

Buffers The pH range of blood is 7.35-7.45 It is extremely important that blood stay in this narrow range, making buffering systems necessary

Buffers The body has two types of buffering systems: < chemical < physiological A chemical buffer is a substance that removes or releases H+ from a system by binding to them or releasing them

Buffers A physiological buffer is a system that stabilizes pH by controlling the body’s output of acids, bases & CO2 The two systems that act as physiological buffers are the respiratory and urinary systems

Chemical Buffers The bicarbonate buffering system CO2 + H2O H2CO3 HCO3- + H+ The phosphate buffering system H2 PO4- HPO42- + H+

Chemical Buffers The protein buffering system - COOH - COO- + H+ OR - NH2 + H+ - NH3+

Physiological Buffers The respiratory system is a two to three times stronger buffering system than chemical buffers The bicarbonate buffering system CO2 + H2O H2CO3 HCO3- + H+

Physiological Buffers The urinary system is most powerful buffering system in the body H+ are secreted from the blood into kidney tubules where they bind with HCO3-, HPO42- or ammonia

Physiological Buffers The bound and free H+ are then excreted in the urine The removal of free H+ is what makes this buffering system so powerful

Buffering Overview

Buffering Overview

- a covalently bonded, polar molecule Water - a covalently bonded, polar molecule aaaaaaaaaaaaa Molecules are said to be polar if they have slight opposite charges on either end

The slight attraction between the negative end of one molecule and the positive end of another results in a… aaaaaaaaaaaaaaaaa

Water - Polarity leads to adhesion and cohesion aaaaa - Polarity leads to adhesion and cohesion Adhesion and cohesion lead to capillary action and surface tension - High specific heat leads to temperature stability - High heat of vaporization leads to evaporative cooling

Water aaaaa - Spheres of hydration form electrostatic interactions, keeping ions from interacting with each other - This characteristic means water has a high degree of solvency and chemical reactivity

Water aaaaa - Water also ionizes into H+ and OH- which can be incorporated into other molecules or released from them

Water

Organic Chemistry The four types of organic compounds Carbohydrates Lipids Proteins Nucleic acids

Carbohydrates The general formula is CH2O The monomers are monosaccharides Functions: Provide energy Structural uses Examples: Plants - starch, cellulose Animals - glycogen, chitin

Lipids Functional group – COOH- (carboxyl) The monomers are fatty acids and alcohols Functions: Storage energy Structural uses Regulation Protection

Lipids Examples: Fats (triglycerides) Phospholipids Steroids Waxes

Lipids The two types of fatty acids Saturated Unsaturated

Proteins Two functional groups – COOH- (carboxyl) and NH2- (amine) The monomers are amino acids Functions: Structural uses Regulation Protection Provide energy

Proteins Examples: Collagen Hormones Enzymes Antibodies

Nucleic Acids The monomers are nucleotides Functions: Heredity Nitrogen base Functions: aaaaaaaaaaa Heredity Protein synthesis Phosphate group Pentose sugar

Nucleic Acids Examples: Double stranded, double helix molecule Single stranded with three forms – tRNA, rRNA, and mRNA DNA RNA

Adenosine triphosphate The fuel of living cells ATP Adenosine triphosphate The fuel of living cells

Definitions Dehydration synthesis – the assembling of organic molecules by extracting water Hydrolysis – the breaking up of organic molecules using water

The Metabolism of Macromolecules

Enzymes Proteins that function as biological catalysts by lowering the energy of activation and speeding up chemical processes Enzymes are substrate specific, much like a lock and key Enzymes catalyze reactions without being changed

Enzymes How they work!

Enzymes How they work!

Temperature effects on enzymes pH effects on enzymes Temperature effects on enzymes