Anatomy & Physiology Chapter 2

Van Der Waals Force

week, brief attraction due to random disturbances in the electron clouds of adjacent Atoms. Weakest of all bonds.

Mixture

physically blended but not chemically combined

Solvency

ability to dissolve other chemicals

Hydrophilic

substances that dissolve in water

Hydrophobic

the relatively few substances that do not dissolve in water

Adhesion

the tendency of one substance to cling to another

Cohesion

the tendency of molecules of the same substance to cling to each other

Surface Tension

the cohesion of water that is especially evident at its surface, where it forms an elastic layer called the surface film held together by this Force

Chemical reactivity of water

the ability to participate in chemical reactions

Thermal stability of water

helps to stabilize the internal temperature of the body

Calorie (cal)

The amount of heat energy required to raise the temperature of 1 g of water by 1°C; also the amount of heat energy that 1 g of water releases when it cools by 1°C.

Solution

consists of particles of matter called the solute mixed with more abundant substance called the solvent; particles are under one nanometer in size, do not scatter light, will pass through most selectively permeable membranes, does not separate from the solvent when the solution is allowed to stand

Colloid

particles that range in size from one to 100 nanometers, large and scatter light, are usually cloudy, particles are too large to pass through most selectively permeable membranes, still small enough however to remain permanently mixed with the solvent when the mixture stands

Solute

A substance that is dissolved in a solution.

Solvent

the substance in which the solute dissolves

Emulsion

a suspension of one liquid in another, such as oil and vinegar salad dressing

Acid

any proton donor, a molecule that releases a proton (H+) in water

Base

a proton acceptor

pH

measured by the molarity of H+

Neutral

a solution with a pH of 7. 0

Acidic

pH less than 7

Basic (alkaline)

pH more than 7

Weight per Volume

weight of solute in given volume of solution

Percentage

the weight of solid as a percentage of solution volume, or volume of a liquid as a percentage of total solution volume

Molarity

the number of moles of solute per liter of solution

Milliequivalent per Liter

units used to measure electrolyte concentrations of body fluids

Energy

capacity to do work

Work

A result of a force moving an object a certain distance.

Potential Energy

energy contained in an object because of its position or internal state but that is not doing work at the time

Kinetic Energy

energy of motion, energy that is doing work

Chemical Energy

potential energy stored in the bonds of molecules

Electromagnetic Energy

the kinetic energy of moving packets of radiation called photons

Electrical Energy

has both potential and kinetic forms

Free Energy

the potential energy available in a system to do useful work

Chemical Reaction

a process in which a covalent or ionic bond is formed or broken

Chemical Equation

A representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products

Decomposition Reaction

a reaction in which a single compound breaks down to form two or more simpler substances

Synthesis Reaction

two or more small molecules combine to form a larger one

Exchange Reactions

two molecules exchange atoms or groups of atoms

Reversible Reaction

can go in either direction under different circumstances

Law of Mass Action

chemical law stating that the rate of a reaction is proportional to the concentration of the reacting substances

Equilibrium

a state in which opposing forces or influences are balanced

Concentration

reaction rate increases when the reactants are more of this

Temperature

reaction rate increases as this rises

Catalysts

these are substances that temporarily bind to reactants, hold them in a favorable position to react with each other, and may change the shape of reactants in ways that make them more likely to react

Metabolism

All of the chemical reactions that occur within a living organism

Catabolism

consists of energy-releasing decomposition reactions; breaks covalent bonds and produces smaller molecules from larger ones; releases energy to be used within the body

Anabolism

Energy-storing synthesis reactions driven by the energy released through catabolism; produces fats and proteins

Oxidation

any chemical reaction in which a molecule gives up electrons and releases energy

Reduction

a chemical reaction in which a molecule gains electrons and energy

Carbon Backbones

carbon atoms readily bond with each other and can form long chains, branched molecules, and rings; found in organic molecules

Functional Groups

small clusters of atoms that determines many of the properties of an organic molecule

Polymers

molecules made of a repetitive series of identical or similar subunits called monomers

Monomers

building blocks of polymers

Dehydration Synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule; removal of OH from one molecule and H from another; produces water as a by-product

Hydrolysis

a water molecule ionizes into OH and H; allows for the decomposition of molecules

Carbohydrate

compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body

Monosaccharides

Single sugar molecules

Disaccharides

Carbohydrates that are made up of two monosaccharides

Oligosaccharides

short chains of 3 or more monosaccharides

Glycogen

an energy storage polysaccharide made by cells of the liver

Phosphate Group

ATP is named for its three of these; H2P04; forms acids

Carboxyl Group

a single carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group; usually at the end of a carbon chain; COOH

Amino Groups

found in proteins; NH2

Methyl Groups

Non-polar; will not combine with other molecules if found on both ends of a carbon chain; CH3

Hydroxyl Group

OH; found in sugars and alcohols

Hydrogen Bond

weak attraction between polarized molecules or between polarized regions of the same molecule. Important in the three dimensional folding and coiling of large molecules. Easily disrupted by temperature and pH changes

Double Covalent Bond

sharing of two electron pairs. Often occurs between carbon atoms, between carbon and oxygen, and between carbon and nitrogen.

Single Covalent Bond

sharing of one electron pair

Polar Covalent Bond

covalent bond in which electrons are more attracted to one nucleus than the other, resulting in slightly positive and negative regions in one molecule. Maybe single or double

Non-polar Covalent Bond

covalent bond in which electrons are equally attracted to both nuclei. Maybe single or double. Strongest type of chemical bond.

Covalent Bonds

Bonds created by sharing electrons with other atoms

Ionic Bond

the attraction of a cation to an anion

Chemical Bond

the attractive force that holds atoms or ions together

Molecular Weight

the sum of the atomic weight of a compounds atoms

Compounds

molecules composed of two or more elements

Molecules

chemical particles composed of two or more atoms United by a chemical bond

Cation

A positively charged ion

Anion

A negatively charged ion

Ionization

the process of adding or removing electrons from an atom or molecule, which gives the atom or molecule a net charge

Ions

charged particles with unequal numbers of protons and electrons

Biological Half Life

the time required for half of a radioisotope to disappear from the body

Physical Half Life

the time required for 50% of a radioisotopes atoms to decay to a more stable state

Ionizing Radiation

high energy radiation that ejects electrons from atoms, converting atoms to ions

Radioactivity

the process of decay of radioisotopes

Radioisotopes

unstable isotopes

Atomic Weight

the total number of protons and neutrons in the nucleus of an atom

Isotopes

Atoms with the same number of protons but different numbers of neutrons

Atomic Number

the number of protons in the nucleus of an atom

Trace Elements

An element indispensable for life but required in extremely minute amounts.

Minerals

inorganic elements extracted from the soil by plants and passed up the food chain to humans and other organisms

Biochemistry

the study of the molecules that compose living organisms - especially molecules unique to living things, such as carbohydrates, fats, proteins, and nucleic acid

Free Radicals

chemical particles with an odd number of electrons

Electrolytes

substances that ionize in water, (acids, bases, or salts) and form Solutions capable of conducting electricity

Element

the simplest form of matter that has a unique set of chemical properties

Atoms

smallest unit of matter

Protons

Positively charged particles

Neutrons

the particles of the nucleus that have no charge

Electrons

negatively charged particles

The Defining Factor of an Element

# of Protons in nucleus