Chapter 2

Front 1

Define atom

Back 1

Smallest stable units of matter

Front 2

Define trace elements.

Back 2

14 elements found in the human body in very small amounts.

Front 3

How is it possible for two samples of hydrogen to contain the same number of atoms yet have different weights?

Back 3

Two samples of hydrogen may contain the same number of protons, but are different in number of neurons, thus, making the weight different and making themselves isotopes.

Front 4

Indicate the maximum number of electrons that can occupy each of the first three electron shells (energy levels) of an atom.

Back 4

The first shell can hold 2 electrons
The second shell can hold 8 electrons
The third shell can hold 8 electrons

Front 5

Explain why the atoms of inert elements do not react with one another or combine with atoms of other elements.

Back 5

atoms of inert elements do not react with atoms of another element because their outer shell is completely filled with electrons.

Front 6

Explain how cations and anions form.

Back 6

cations form when an element has a net positive charge by gaining, losing,
or sharing electrons to fill their outermost energy level.
anions form when the net negative charge by obtaining electrons from other atoms.

Front 7

Name and distinguish between the two most common types of chemical bonds.

Back 7

Ionic bonds are chemical bonds created by the elecrical attraction between cations and anions.
Covalent bonds are chemical bonds that are formed not by gaining or losing electrons, but by sharing them with other atoms.

Front 8

Describe the kind of bonds that hold the atoms in a water molecule together.

Back 8

Polar covalent bonds are a type of covalent bonds that produce polar molecules.

Front 9

Relate why we can apply the term molecule to the smallest particle of water but not to that of table salt.

Back 9

we can apply the term molecule to the smallest particle of water but not to table salt because water is kept together by polar covalent bonds, which is a type of covalent bonds while table salt is a form of ionic bonds

Front 10

describe the different states of matter in terms of shape and volume

Back 10

solid- maintain their volume and their shape at ordinary temps and pressures
liquid- constant volume but no fixed shape, determined by shape of container
gas- neither a constant volume of a fixed shape, can be compressed or expanded

Front 11

by what means are water molecules attracted to each other

Back 11

small positive charges on the hydrogen atoms of one polar molecule can be attracted to negative charges on another polar molecule, and this can change the shapes of the molecules or pull adjacent molecules together.

Front 12

explain why small insects can walk on the surface of a pond, and tears protect the surface of the eye from dust particles.

Back 12

small insects can walk on the surface of a pond because the hydrogen bonds between water molecules slow the rate of evaporation and create a phenomenon known as surace tension which serves as a barrier that keeps small objects from entering the water. Similarly, small objects such as dust particles are prevented from touching the surface of the eye by the surface tension produces by a layer of tears.

Front 13

The chemical shorthand used to describe chemical compounds and reactions effectively is known as what

Back 13

chemical notation

Front 14

Identify and describe three types of chemical reactions important in human physiology

Back 14

Decomposition- a reaction that breaks a molecule into smaller fragments.
Synthesis- assembles smaller molecules into larger molecules.
Exchange- parts of the reacting molecules are shuffled around to produce new products.

Front 15

Distinguish the roles of water in hydrolysis and dehydration synthesis reactions

Back 15

in hydrolisys, one of the bonds in a complex molecule is broken, and the component of a water molecule are added to the resulting fragment while in dehydration synthesis, is the formation of a complex molecule by the removal of a water molecule.

Front 16

In cells, glucose, a six-carbon molecule, is converted into two three-carbon molecule by a reaction that releases energy. what is the energy source?

Back 16

The reaction is a decomposition reaction

Front 17

What is an enzyme?

Back 17

specific proteins that are used to perform most of the complex synthesis and decomposition reactions in your body.

Front 18

Explain the difference between metabolites and nutrients?

Back 18

Metabolites are molecules that can be synthesized or broken down by chemical reactions inside our bodies while nutrients are essential metabolites that are normally obtained from the diet. Both can be categorized as either organic or inorganic.

Front 19

Why are enzymes needed in our cells?

Back 19

Enzymes are needed in our cells because without them, we would have to relly on the changes in temp or acidity, which are deadly to cells.

Front 20

Define electrolytes.

Back 20

soluble inorganic molecules whose ions will conduct an electrical current in solutions

Front 21

Distinguish between hydrophilic and hydrophobic molecules.

Back 21

hydrophilic molecules react readily with water molecules while hydrophobic molecules do not readily react with water.

Front 22

Explain how the ionic compound sodium chloride dissolves in water.

Back 22

Ionic compound sodium chloride dissolves in water when catons i solution will move toward the negative side, or negative termnal, and anions will move toward the positive terminal.

Front 23

Define Ph.

Back 23

The negative logarithm of the hydrogen ion concentration in moles per liter (Mol/L)

Front 24

Explain the difference among an acid, a base, and a salt.

Back 24

an acid is any solute that dissociates in solution and releases hydrogen ions, thereby lowering the pH
a base is a solute that removes hydrogen ions from a solution and thereby acts as a proton acceptor.
And a salt is an ionic compound consisting of any cation except a hydroxide ion.

Front 25

What is the significance of pH in physiological systems?

Back 25

pH is a special shorthand that is used to express the hydrogen ion concentration in body fluids

Front 26

List the three structural classes of carbohydrates, and give an example of each.

Back 26

monosaccharides- Glucose
disaccharides-Sucrose
polysaccharides- Glycogen