Chapter 3 - Chemistry Overview

Question 1

Chemistry

Answer 1

Study of the material that comprises all physical objects; study of matter

Question 2

6 most abundant elements in humans

Answer 2

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Calcium ; CHNOPCa

Question 3

Most common elements in most organisms

Answer 3

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur

Question 4

Macromolecule

Answer 4

Large, chain-like molecule such as DNA

Question 5

Mixtures

Answer 5

Combinations of substances in which each substance retains its own chemical properties

Question 6

Solution

Answer 6

Homogeneous mixture in which one substance (solute) is scattered evenly throughout another substance (solvent)

Question 7

Concentration

Answer 7

Amount of solute divided by total amount of solution

Question 8

Colloid

Answer 8

Heterogeneous mixture in which particles are large enough to scatter light, yet they are too small to settle out of the mixture (e.g. Gelatin or milk)

Question 9

Suspension

Answer 9

Heterogeneous mixture that contains particles large enough to settle out of the mixture (e.g. Muddy water in a flask)

Question 10

Octet rule

Answer 10

Most atoms have outer electron shells that can hold a max of 8 electrons (except hydrogen & helium atoms - can only hold 2)

Question 11

Ionic bond

Answer 11

Force of attraction between oppositely charged particles of matter called ions

Question 12

Electrolytes

Answer 12

Ions in a solution that can conduct an electrical current

Question 13

Ion

Answer 13

Atom or molecule that has more or fewer electrons than protons

Question 14

Cation

Answer 14

Positively charged ion

Question 15

Anion

Answer 15

Negatively charged ion

Question 16

Covalent bond

Answer 16

Forms when two atoms share one or more outer electrons

Two types: nonpolar & polar

Question 17

Nonpolar

Answer 17

Molecules that share electrons equally

Question 18

Polar

Answer 18

Share electrons unequally (an electron orbits one of atoms longer than other)

Question 19

Hydrogen bond

Answer 19

Attraction between a hydrogen atom located within one polar molecule and an oxygen or nitrogen atom located within another molecule

Question 20

Cohesion

Answer 20

(stick together) process where intermolecular hydrogen bonds hold adjacent water molecules together

Question 21

Adhesion

Answer 21

(stick to) process where intermolecular hydrogen bonds also allow water molecules to stick to non-water molecules

Question 22

Isotope

Answer 22

Element with an atomic weight that is different from that of the most common form of the element

Question 23

Radioactive decay

Answer 23

Isotopes that are unstable and lose nuclear particles and energy over time

Question 24

Energy

Answer 24

Force that moves matter

Question 25

Work

Answer 25

Movement of matter

Question 26

Potential energy

Answer 26

Stored energy; energy of "position"

Question 27

Kinetic energy

Answer 27

Energy in motion Includes: chemical energy, electrical energy, electrochemical energy, radiant (electromagnetic) energy, mechanical energy

Question 28

Free radicals

Answer 28

Molecules that have unpaired electrons in their outer electron shell

Question 29

Antioxidants

Answer 29

Chemicals that react with free radicals & prevent their reactions with vital cellular compounds (Vitamins A, C, E are important antioxidants)

Question 30

Factors affecting reaction rate

Answer 30

1. Size of reactants 2. Concentration of reactants 3. Temperature 4. Concentration of catalysts

Question 31

Catalyst

Answer 31

Substance that speeds up a reaction without becoming part of any product ^[catalysts] = ^reaction rate

Question 32

Functions of water in the body

Answer 32

1. It is the medium in which chemical reactions occur 2. It can act as chemical reactant 3. It acts as lubricant to reduce friction 4. It absorbs & dissipates heat 5. It acts as a shock absorber

Question 33

Substrate reactant

Answer 33

Chemical worked on by an enzyme

Question 34

Substrate-binding site

Answer 34

Site where substrate must first attach to enzyme

Question 35

Denaturation

Answer 35

Any change in an enzyme's shape that adversely affects its normal functioning

Question 36

Dehydration synthesis

Answer 36

Formation of most organic compounds

Question 37

Hydrolysis

Answer 37

Enzyme breaks compound into 2 smaller products & breaks a water molecule into H and OH.

Question 38

End-product inhibition

Answer 38

Products of a reaction bind to an enzyme & prevent it from working

Question 39

Competitive inhibition

Answer 39

"foreign" substrate competes with normal substrate for the substrate-binding site

Question 40

Allosteric/noncompetitive inhibition

Answer 40

Foreign substance binds to a part of the enzyme other than the substrate-binding site

Question 41

Carbohydrates (saccharides)

Answer 41

1. Primary source of energy for body's cells | 2. Cell markers & part of nucleic acids

Question 42

Lipids

Answer 42

1. Contain C, H, O 2. Important source of energy 3. Insoluble in water

Question 43

Protein

Answer 43

1. Most important structural component in body 2. Polymer of amino acids - amino acids contain C, H, O, N, some S

Question 44

Peptide bond

Answer 44

Covalent bond that holds two amino acids together