Anatomy & Physiology

ch.1-3

Matter

a substance that has mass and occupies space

What are the three forms of matter?

solid, liquid, and gas

atom

the smallest particle that exhibits the chemical properties of an element

element

substance composed of only one atom

How many elements are there?

92

What is the smallest and lightest element?

Hydrogen

What is the largest and heaviest element?

Uranium

3 groups elements are categorized in?

major, minor, and trace elements

Percent of major and minor elements are?

Major: 98% Minor: Less than 1%

What are the trace elements?

oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, sulfur, potassium, sodium, chlorine, magnesium, and iron

Subatomic particles

neutrons, protons, and electrons

atomic mass unit (amu)

mass of a specific atom

neutron

uncharged, neutral

proton

positive charge (+1)

atomic nucleus

When neutrons and protons compose almost the entire mass or weight of an atom and are located at the center, or core of the atom

electron

negative charge (-1)

atomic number

indicates the number of protons in an atom of that element and is located above its symbol in the periodic table

atomic mass

indicates the mass of both protons and neutrons in the atomic nucleus, and it reflects the "heaviness" of an element's atoms relative to atoms of other elements

How do you calculate the proton number?

No calculations its simply the Atomic number

How do you calculate the neutrons?

Atomic mass (p + n) − atomic number (p

How do you calculate the electrons?

Proton number (p)

isotopes

different atoms of the same element that have the same number of protons and electrons but differ in the number of neutrons.

____ **exhibit essentially identical chemical characteristics but have different atomic masses.**

Isotopes

carbon 12

6 protons, 6 neutrons, 6 electrons

carbon-13

6 protons, 7 neutrons, 6 electrons

carbon-14

6 protons, 8 neutrons, 6 electrons

average atomic mass

weighted average of the atomic mass for all isotopes of an element

radioisotopes

unstable isotopes that emit high-energy radiation

physical half-life

The time it takes for 50% of the radioisotope to become stable

biological half-time

the time required for half of the radioactive material to be eliminated from the body

valence shell

columns based on the number of electrons

octet rule

tendency for atoms to to maintain an outer shell with eight electrons

chemical compounds

stable associations between two or more elements combined in a fixed ratio

ions

atoms or groups of atoms with either a positive charge or a negative charge

Sodium ion (Na+)

-Most common extracellular cation

-Participant in conducting electrical signals in nerves and muscle

Sodium ion (Na+)

-Most important in osmotic movement of water

Sodium ion (Na+)

-Sodium gradient involved in cotransport of other substances across a plasma membrane

Sodium ion (Na+)

Potassium ion (K+)

-Most common intracellular cation

-Participant in conducting electrical signals in nerves and muscle

Potassium ion (K+)

-Role in glycogen storage in liver and muscle

Potassium ion (K+)

-Function in pH balance

Potassium ion (K+)

Calcium ion (Ca2+)

-Hardness of bone and teeth

-Muscle contraction

Calcium ion (Ca2+)

-Exocytosis (including release of neurotransmitter)

Calcium ion (Ca2+)

-Blood clotting

Calcium ion (Ca2+)

-Second messenger in hormonal stimulation of cells

Calcium ion (Ca2+)

Magnesium ion (Mg2+)

Required for ATP production

Hydrogen ion (H+)

Concentration determines pH of blood and other fluids of the body

Chloride ion (Cl-)

-Alters nerve cell responsiveness to stimulation

-Component of stomach acid (HCl)

Chloride ion (Cl-)

-Chloride shift in erythrocytes

Chloride ion (Cl-)

Bicarbonate ion (HCO3-)

-Conversion of CO2 gas to HCO3-, which is transported in the blood

-Buffering of pH in blood

Bicarbonate ion (HCO3-)

Phosphate ion (PO43-)

-As Ca3(PO4)2, it hardens bone and teeth

-Component of phospholipids (membranes)

Phosphate ion (PO43-)

-Component of nucleotides, including ATP and nucleic acids (DNA and RNA)

Phosphate ion (PO43-)

-Most common intracellular anion

Phosphate ion (PO43-)

-Intracellular buffer

Phosphate ion (PO43-)

cations

ion with positive (+) charge

anions

ion wit negative (-) charge

polyatomic ions

composed of more than one atom

ionic bonds

Positively charged cations and negatively charged anions may bind together by electrostatic interactions

ionic compound

when two or more ions are held together

molecular compounds

composed of two or more different elements

covalently bonded molecule

The sharing of electrons between atoms

molecular formula

the number and types of atoms composing a molecule (H2CO3)

structural formula

complementary to its molecular formula and exhibits not only the numbers and types of atoms but also their arrangements within the molecule (O\=C\=O)

isomers

molecules composed of the same number and types of elements but arranged differently in space

**Important isomers**

**glucose and galactose**

What are the four most common elements of the human body that form covalent bonds? What percentage of these take account of human body weight?

hydrogen (H), oxygen (O), nitrogen (N), and carbon (C). 96% of the body's weight

The number of bonds formed by the four most common elements can be remembered with the acronym what? What does each letter stand for? HONC: hydrogen \= 1, oxygen \= 2, nitrogen \= 3, and carbon \= 4.

HONC: hydrogen \= 1, oxygen \= 2, nitrogen \= 3, and carbon \= 4.

single covalent bond

one pair of electrons shared between two atoms

double covalent bond

sharing of two pairs of electrons between two atoms

triple covalent bond

Three pairs of electrons are shared between atoms in some molecules

Carbon Skeleton

straight chain, branched chain, and a ring

electronegativity

Atoms share electrons in a covalent bond either equally or unequally between the atoms. How they share is determined by the relative attraction each atom has for electrons

nonpolar covalent bond

two atoms of the same element, such as two hydrogen atoms, two oxygen atoms, or two carbon atoms, have equal attraction for electrons, they share the electrons equally

polar covalent bond

Different types of atoms have varying degrees of electronegativity, or attraction for electrons, and thus may share the electrons unequally

polar

refers to the "poles" of partial electrical charges, which are analogous to poles of a magnet.

molecule

composed of atoms or ions held by an attraction or chemical bond

nonpolar molecule

contain nonpolar covalent bonds, which are bonds formed between the same elements

(e.g., C—C, O—O)

nonpolar molecule

amphipathic molecule

Molecules that contain both nonpolar and polar components

intermolecule attractions

Molecules sometimes have weak chemical attractions to other molecules

hydrogen bond

a weak attraction between a partially positive (δ+) hydrogen atom within a polar molecule and a partially negative (δ−) atom within a polar molecule

hydrophobic interactions

which results when nonpolar molecules are placed in water or another polar substance

polarity

an unequal sharing of electrons between the oxygen atom and each of the two hydrogen atoms

What are the three phases water is present?

a gas (water vapor), a liquid (water), and a solid (ice)

What functions do water serve as when in liquid form?

Transports. Substances are dissolved in water and moved throughout the body in water-based fluids (e.g., blood and lymph).

functions of liquid water

\-Lubricates. Water-based fluids located between body structures decrease friction (e.g., serous fluid between the heart and its sac, synovial fluid within joints).

functions of liquid water

\-Cushions. The force of sudden body movements is absorbed by water-based fluids (e.g., cerebrospinal fluid surrounding the brain and spinal cord).

functions of liquid water

\-Excretes Wastes. Unwanted substances are eliminated in the body dissolved in water (e.g., urine).

cohesion

is the attraction between water molecules

surface tension

the inward pulling of cohesive forces at the surface of water

adhesion

the attraction between water molecules and a substance other than water

heat of vaporization

the energy required for the release of molecules from a liquid phase into the gaseous phase for 1 gram of a substance

solvent

substance holding a solute

solutes

substance that dissolves in solvent

hydrophilic

substances that dissolve in water