Anatomy Chapter 2 Test

Solid

Definate shape and volume

Liquid

Definite volume but the shape

Gas

No definite shape or volume

Matter

Anything that takes up space and has mass

Physical Change

Where the basic nature of the substance is unaltered

What’s an example of physical change?

Ice into water

Chemical Change

Where the basic nature of the substance is changed

What’s an example of chemical change?

Digestion of food

Energy has no ___ and doesn’t take up what?

It has no mass and takes up no space

Energy is

the ability to do work

Kinetic Energy

When work is being done (motion occurs)

Potentional energy

Stored energy

How many forms of energy are in the body?

Four

Chemical energy

Occurs when chemical bonds are broken

What’s an example of chemical energy?

Digesting food releases energy as chemical bonds are broken

Electrical Energy

Results from movement of charged particles

What’s an example of electrical energy?

Charged ions moving across cell membrane and electric currents called nerve impulses moving through the body

Mechanical Energy

Results in matter being moved

What’s an example of mechanical energy?

Muscle contractions moving bones which move you

Radiant energy

Travels in waves which includes x-rays, infrared radiation, visible light, radio and ultraviolet waves

What’s an example of radiant energy?

Visible light stimulates our vision, UV radiation stimulates tanning and vitamin D formation

Elements are what

Unique substances that cannot be broken into simpler substances by ordinary chemical methods

How many known elements are there?

118 known elements

How many elements are naturually occuring?

92 elements

Humans are made up of what four elements?

oxygen, carbon, hydrogen and nitrogen

Oxygen is what percentage of the body?

65%

Carbon is what percentage of the body?

18.5%

Hydrogen is what percentage of the body?

9.5%

Nitrogen is what percentage of the body?

3.2 %

Every element is composed of

the same atom

Protons

Positive charge - determine the chemical characteristics of the atom

Neutrons

No charge - these impact the radioactivity of the atom

Electrons

Negative charge - these cause attraction and bonding to the other atoms

Ions

Atoms that have gained or lost electrons and now have a positive or negative charge

Atomic number

Number of protons

Atomic Mass

Sum of protons and neutrons of a particular atom

Atomic weight

Average of all the atomic masses of an atom

Isotopes

Atoms with the same number of protons and electrons

Radioisotopes

Isotopes that release radioactivity

Radioisotopes are used to

tag biological molecules to follow them

What’s an example of radioisotopes?

Used to scan the thyroid gland; used in PET scans

Molecules

2 or more of the same atoms bonded together

Diatomic molecules

2 of the same atoms bonded together; these make up many common gases

Example of diatomic molecules

O2, N2, and H2

Compounds occur when

2 or more different atoms are bonded together

Example of compounds

Hydrogen gas and oxygen gas

Chemical Bond

An energy relationship between electrons of reacting atoms

Electrons orbit the what

nucleus of the atom in the layers

The outer layer of electrons

Valence shell

Ionic bonds

Occur when atoms give up one or more electrons; form positive and negative ions

What forms ionic molecules?

Positive and negative ions

Covalent bonds

Occur when atoms share valence electrons

Non-polar covalent molecules

Molecules occur when the electrons are equally shared

Polar covalent molecules

occur when the electrons are NOT equally shared

Hydrogen bonds

very weak bonds formed by the attractions to the positive areas of another polar covalent molecules and the negative atom in a different molecule

Hydrogen bonds form what?

Surface tension

Chemical reactions

Involve the making or breaking of bonds between atoms; number of atoms stay the same but occur in different combos

3 main types of reactions are

Synthesis, decomposition, and exchange

Synthesis reactions

these occur when 2 or more atoms combine to form a larger molecule

Exchange reactions

occur when a molecule is broken down into smaller molecules

Exchange reactions

Occur when atoms in a molecule change places with molecules of a different molecule

Inorganic compounds

Do not contain carbon

2 exceptions of inorganic compounds that do contain carbon

Carbon dioxide and carbon monoxide

Organic compounds

contain carbon and are usually large molecules

Water makes up

55-65% of body weight

Water helps forms body fluids like what

blood, synovial fluid, etc

Salts

Inorganic molecules that are not acids or bases

Salts are important for what

Bone formation, oxygen transportation, nerve impulses, muscle contractions, etc

Electrolytes

ions that dissociate in water and conduct an electrical current

Acids and bases are

electrolytes and dissociate in water

Acids are

substances that are proton donors and release H+ ions into a solution

Bases are

substances that are proton receptors

What happens when acids and bases are mixed?

They neutralize each other forming water and a salt

Neutral

Around 7

Below 7 on the ph scale is

acidic

Above 7 on the ph scale is

alkaline

Buffers

absorb H+ and OH Ions and are used in the body to maintain constant pH’s

What’s the normal pH range in blood?

7.35-7.45

Name 2 symptoms of acidosis

Rapid breathing and confusion

Name 2 symptoms of alkalosis

Muscle cramps and seizures

Carbohydrates are

classified by the number of units making the molecule