Chapter 2

Question 1

Define mixture

Answer 1

Two or more substances that are mixed together

Question 2

How is a mixture different from a molecule or compound?

Answer 2

Mixture has no chemical bonds whereas compounds do.

Question 3

3 types of mixtures

Answer 3

Solution, Colloid and suspension

Question 4

What are the inorganic compounds in the body?

Answer 4

Water, salts, acid and bases

Question 5

What are the organic compounds in the body?

Answer 5

Carbohydrates, lipids, proteins and nucleic acids

Question 6

Define element and atom

Answer 6

Element: something that cannot be broken down into something smaller
Atom: the smallest particle of an element that retains its properties

Question 7

What elements makes up 96% of the body?

Answer 7

Oxygen, carbon, hydrogen and nitrogen

Question 8

Define atomic nucleus

Answer 8

The small dense region consisting of protons and neutrons at the center of an atom

Question 9

Define atomic number

Answer 9

The number of protons in the nucleus, which determines the chemical properties of an element and its place in the periodic table

Question 10

Define mass number

Answer 10

Combined number of protons and neutrons in an atom

Question 11

Isotope and atomic weight

Answer 11

The average weight of all isotopes of an element

Question 12

What are radioisotopes?

Answer 12

The isotopes that are unstable due to presence of extra neutrons in their nuclei and emit various types of radiation

Question 13

Is a molecule different than a compound?

Answer 13

Molecule is two or more atoms held together by chemical bonds. Compounds are two or more different elements held together by chemical bonds.

Question 14

What is a solution? give an example

Answer 14

solute particles are very tiny, do not settle out or scatter light. Homogeneous. Solvent is usually liquid (water). Solute is present in smaller amounts. Example would be blood sugar. Glucose=solute. blood = solvent.

Question 15

what is a true solution?

Answer 15

transparent. examples are air, salt solution and sugar solutions.

Question 16

What is a colloid?

Answer 16

type of mixture where solute particles are larger than in a solution, but they do not settle. solution is therefore cloudy. this is going to be heterogenous

Question 17

What is solution to gel transformation?

Answer 17

some examples is jell-o: liquid to gel. cytosol of cell is also sol-gel type solution.

Question 18

What is a suspension?

Answer 18

A type of mixture where solute particles are very large, settle out, and may scatter light. Heterogenous. example would be water and sand.

Question 19

The three common ways to express solution concentrations?

Answer 19

1. percent of solution in a total solutions
2. milligrams per deciliter
3. Molarity

Question 20

Define chemical bonds? what plays a role in all chemical bonds?

Answer 20

a strong force of attraction holding atoms together in a molecule or crystal, resulting from the sharing or transfer of electrons. Electrons play a role in all chemical bonds.

Question 21

What is an electron shell? A valence shell?

Answer 21

thought of as an orbit followed by electrons around an atom’s nucleus. A valence shell is the outermost shell of an atom containing the valence electrons

Question 22

What is the octet rule? Why is it important in chemical bonding?

Answer 22

the octet rule refers to the tendency of atoms to prefer to have eight electrons in the valence shell. It is important because sharing electrons give both atoms a full valence shell

Question 23

Define the 3 types of chemical bonding and explain each.

Answer 23

ionic: complete transfer of valence electrons between atoms
covalent: sharing electrons to form pairs
Hydrogen: utilizes dipole-dipole attraction

Question 24

Define Ions

Answer 24

an atom or molecule with a net electric charge due to the loss or gain of the one or more elctrons.

Question 25

What is a cation?

Answer 25

Cations are ions that are positively charged.

Question 26

What is an anion?

Answer 26

Anions are negatively charged.

Question 27

Describe the two types of covalent bonds

Answer 27

polar covalent: a bond in which electrons are shared unequally Nonpolar covalent: a bond in which the electrons are shared equally.

Question 28

is a hydrogen bond a true bond?

Answer 28

No, it is an attraction.

Question 29

Define chemical reaction, reactant and product

Answer 29

Chemical reaction: a process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction. Reactant: A substance that takes part in and undergoes change during a reaction Product: the species formed after a reaction occurs.

Question 30

three types of chemical reactions and explain each in detail

Answer 30

Synthesis, decomposition and exchange

Question 31

What are the factors that affect the speed of a chemical reaction?

Answer 31

Particle size: the smaller the size the faster reaction concentration of reactants: increase in concentration will increase rate of reaction. temperature: High temperature increases reaction

Question 32

What is the difference between an inorganic and organic compounds?

Answer 32

Most of the organic compounds contain carbon while inoraganic compounds do not

Question 33

List all the major inorganic compounds and explain each

Answer 33

1. Water-most abundant inorganic compound. 60-80% of the volume of living cells. Solvent. Covalent polar bond. Hydrogen bonding between molecules (surface tension) 2. salts-Ionic compounds. solutes. 3. Acid and Bases

Question 34

Explain the pH scale. What do H+ and OH- have to do with this scale?

Answer 34

The pH scale is the concentration of hydrogen ions [H+] in a solution.

Question 35

What is a buffer? how does a buffer work?

Answer 35

Buffer: strong acid to weak acid OR strong base to weak base; resists large swings in pH.

Question 36

Why is carbon such an important organic compound?

Answer 36

carbon can form stable bonds with many elements, including itself.

Question 37

What are the three classes of carbohydrates?

Answer 37

1. Monosaccharides: glucose, fructose and galactose 2. disaccharides: two monosaccharides bonded together; sucrose 3. polysaccharides: many monosaccharides bonded together

Question 38

Describe the three main types of lipids. Which is the most common dietary lipid?

Answer 38

1. triglycerides: fats (solid, oils, liquid). glycerol and fatty acids (monomer). Fatty acids: saturated and unsaturated (double bond--healthy) Most common dietary lipid. 2. Phospolipids: modified triglycerides. contains Glycerol, 2 fatty acids, and a phosphorous nitrogen-containing group Hydrophilic and hydrophobic arrangement. plasma membrane. 3. steroids: contains four interlocking hydrocarbon rings. Ex: cholesterol (most important); hormones.

Question 39

What is the difference between saturated and unsaturated fatty acids?

Answer 39

An unsaturated fatty acid contains a double bond. which is healthier for the body.

Question 40

What are the most important organic compounds?

Answer 40

1. carbohydrates--preferred energy source by the body. Covalent; carbon, hydrogen, oxygen. 2. lipids- covalent; insoluble in water 3. proteins- the most diverse organic compounds in the body. chains of amino acids. classified by structure shape and function. 4. nucleic acids- the largest molecule in the body. made of strands of nucleotides

Question 41

What are amino acids?

Answer 41

amino acids are the building blocks of proteins.

Question 42

How are proteins classified?

Answer 42

Classified by: 1. structure: primary, secondary, tertiary, and quaternary 2. shape: fibrous (like collagen) and Globular (like hemoglobin) 3. function: structure, enzymes, transport, contractile, communication and defense.

Question 43

Define denaturation

Answer 43

When the bonds in protein start breaking down, modifying the structure of the protein. Caused by extreme pH differences or extreme temperature changes.

Question 44

Define enzyme and catalyst. what is a cofactor and coenzyme?

Answer 44

enzymes: globular proteins Catalyst: lowers the activation energy to start a chemical reaction. cofactor: metal ion that is required for an enzyme's role as a catalyst. Coenzyme: vitamins that is required on the active site of the enzyme

Question 45

distinguish between the types of nucleic acids

Answer 45

1. Deoxyribonucleic acids (DNA): genetic blueprint for synthesis of all proteins. double strand of nucleotides; double helix. Adenine, thymine, cytosine or guanine. 2. Ribonucleic acid (RNA): links DNA to protein synthesis. single strand of nucleotides. adenine, uracil, guanine and cytosine. three types mRNA, tRNA, rRNA

Question 46

What is ATP? Why is it important?

Answer 46

Its a special type of nucleotide containing: adenine (nitrogenous base), ribose (sugar) and three phosphates. Its the energy carrier needed to power all chemical reactions in cells.