BIO 112 Chapter 2 Flashcards

ECPI LPN

Matter

Anything that takes up space and has mass.

Matter is composed of

elements

Mass

Amount of matter present

Weight

Heaviness due to gravitational pull on mass

Elements

Simplest types of matter with certain chemical properties

Compounds

Chemical combinations of different elements

Atoms

Smallest particles of an element that have properties of the element

Atomic Structure

Protons, Neutrons, and Electrons.

Protons

Large particles; carry a single positive charge

Neutrons

Large particles; carry no electrical charge

Electrons

Small particles; carry a single negative charge

Atoms consist of a

central nucleus (protons + neutrons) and electrons in constant motion around the nucleus

The number of protons equal the number of

electrons in an atom; therefore, atoms are electrically neutral

Atomic Number

the number of protons in the nucleus of an atom

Mass Number

The number of protons plus the number of neutrons in one atom

Molecule

Particle formed when two or more atoms chemically combine

Compound

Particle formed when two or more atoms of different elements chemically combine

Molecular Formula

depict the elements present and the number of each atom present in the molecule

Chemical bonds form when

atoms combine with other atoms.

Electron shells

Depicted as simple circles around nucleus; each shell holds differing numbers of electrons

The first shell of an atom can hold

2 electrons

The second and third shell of an atom can hold

8 electrons

_ are filled first, and are stable with certain number of electrons in the outermost shell

Lower energy shells/inner orbits

Electrons in the outermost shell determine whether

atom will react with other atoms to form chemical bonds

Ionic Bonds

strong chemical bonds formed when ions of opposite charge attract

Covalent Bonds

Strong chemical bonds, formed between atoms that share electrons

Hydrogen Bonds

Very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electrostatic atom in another molecule

_ is an important for protein and nucleic acid structure

Hydrogen Bonds

Ion

an electrically charged atom that gains or loses electrons to become stable

Cation

A positively charged ion, formed when an atom loses electrons

Anion

A negatively charged ion, formed when an atom gains electrons

Synthesis Reaction

more complex chemical structure is formed

A+B>AB

Decomposition Reaction

chemical bonds are broken to form a simpler chemical structure

AB>A+B

Exchange Reaction

chemical bonds are broken and new bonds are formed

AB+CD>AD+CB

Reversible Reactions

the product can change back to the reactants A+B<>AB

Electrolytes

substance that release ions in water. The solution can conduct an electrical current

Acids

Electrolytes that dissociate to release hydrogen ions in water

Bases

Substances that release ions that can combine with hydrogen ions

Salts

Electrolytes formed by the reaction between an acid and a base

Study of acids and bases involves measuring the

H+ ion concentration in a solution

pH Scale

indicates the concentration of H+ ions in a solution

Neutral

A pH of 7 indicates equal concentrations of H+ and OH-. (Water)

Acidic

A pH of <7 indicates a greater concentration of H+ than OH-

Basic (Alkaline)

A pH >7 indicates a higher concentration of OH- than H+

Organic Molecules

-Contain C and H

-Depending on the type, they will dissolve in water or organic liquids

-Water-soluble organic compounds do not release ions, and are non-electrolytes

carbohydrates, proteins, lipids, nucleic acids are

organic molecules

Carbohydrates

-main source of energy

-water soluble

Monosaccharides

Single sugar molecules (glucose, fructose)

Disaccharide

Double sugar (sucrose, lactose)

Polysaccharides

Complex carbohydrates (starch, glycogen, cellulose)

Lipids

-Insoluble in water, but soluble in organic solvents

-Include triglycerides (fats), phospholipids, steroids

-Important component of cell membranes, and have several functions in cells

Triglycerides

most abundant lipids in your body and the richest source of energy

Phospholipids

similar to triglycerides, exempt that they consist of glycerol, 2 fatty acids and a phosphate group

Saturated fatty acids

-Have only single carbon to carbon bonds

-Most are solid at room temperature

-Most are animal origin

Unsaturated fats

-Have one or more carbon to carbon double bond

-Most are liquid at room temperature

-Most are of plant origin

Proteins

Used as structural materials, energy source, hormones, receptors, enzymes, antibodies

Peptide bonds

Bonds between amino acids

Nucleic acids

DNA and RNA

Nucleotides

building blocks of nucleic acids

DNA

deoxyribonucleic acid; a double chain of nucleotides

RNA

ribonucleic acid; a single chain of nucleotides