Chemical Basis for Life

Question 1

matter

Answer 1

anything that occupies space and has mass

Question 2

mass

Answer 2

amount of matter a substance contains

Question 3

weight

Answer 3

the force of gravity acting on an object with mass

Question 4

volume

Answer 4

the amount of space an object takes up

Question 5

the atom

Answer 5

consists of neutrons, protons, and electrons

Question 6

atomic number

Answer 6

number of protons an atom has

Question 7

mass number

Answer 7

total number of protons and neutrons

Question 8

ions

Answer 8

any particle with a positive or a negative charge due to a gain or loss of electrons

Question 9

cation

Answer 9

positively-charged ion

Question 10

anion

Answer 10

negatively-charged ion

Question 11

isotopes

Answer 11

different atoms of a single atom that has the same amount of protons but different amount of neutrons

Question 12

ionic bond

Answer 12

created by the loss and gain of valence electrons from opposing charges which attract each other

Question 13

covalent bond

Answer 13

caused when two or more atoms bond by sharing valence electrons; their is neither a loss or gain of electrons

Question 14

non-polar covalent bond

Answer 14

when atoms in a covalent bond share electrons equally

Question 15

polar covalent bond

Answer 15

when atoms in a covalent bond do not share electrons equally

Question 16

hydrogen bond

Answer 16

when hydrogen forms a covalent bond with another atom, it will form a bond with other atoms that are also covalently bonded to hydrogen; no electrons are transferred from the atoms so it is not a true bond; this bond can form cohesion and adhesion

Question 17

surface tension

Answer 17

results from formation of hydrogen bonds between the outermost layer of water molecules and the underlying molecules

Question 18

capillarity

Answer 18

causes water to climb up the sides of a container due to the attraction between the (+) charge of water molecules and the (-) charge of the surface of the glass

Question 19

synthetic reaction

Answer 19

occurs when two or more atoms combine to form a new and larger molecule

Question 20

anabolism

Answer 20

the process of a synthetic reaction that occurs in the body

Question 21

decomposition reaction

Answer 21

occurs when a chemical is broken down into small components

Question 22

catabolism

Answer 22

the process of a decomposition reaction that occurs in the body

Question 23

exchange reaction

Answer 23

combination of decomposition and synthetic reactions; The bond between A & B and between C & D breaks (decomposition.) New bonds are formed between A & D and between B & C (synthesis.)

AB + CD 🡪 AD + BC

Question 24

solute

Answer 24

any substance that dissolves within another substance

Question 25

solvent

Answer 25

any liquid that dissolves a solute

Question 26

solution

Answer 26

the end product of a solute dissolved in a solvent

Question 27

true solution

Answer 27

a homogeneous mixture of two or more substances in which substance dissolved (solute) in solvent has the particle size of less than 10-9 m or 1 nm; particles will not settle over time

Question 28

colloid solution

Answer 28

a phase separated mixture in which one substance of microscopically dispersed insoluble or soluble particles is suspended throughout another substance; particles will not settle over time

Question 29

suspension solution

Answer 29

a heterogeneous mixture in which the solid particles are spread throughout the liquid without dissolving in it; the particles in suspension are larger than the particles in a solution and will settle over time

Question 30

ionization

Answer 30

when inorganic acids, bases, or salts are dissolved in water and they separate into ions

Question 31

acid

Answer 31

dissociates into one or more hydrogen ions (H+); dissociates into one or more anions; proton donor

Question 32

base

Answer 32

alkaline; dissociates into one or more hydroxide ions (OH-); dissociates into one or more cations; proton acceptor

Question 33

salts

Answer 33

dissociates into both anions and cations; does not dissociate into hydrogen nor hydroxide ions; ionic salts are called electrolytes

Question 34

pH scale

Answer 34

pH < 7 = acidic pH > 7 = alkaline (basic) pH = 7 = neutral

Question 35

buffers

Answer 35

substances that maintain a neutral pH level; converts strong acids and bases into weak acids and bases

Question 36

carbohydrates

Answer 36

includes sugars, starches, glycogen, and cellulose; can provide energy, structural support, and can become stored energy

Question 37

monosaccharides

Answer 37

building blocks of carbohydrates; includes glucose, fructose, galactose, deoxyribose, and ribose

Question 38

disaccharides

Answer 38

formed by combining two monosaccharides; loses a molecule of water during this process; includes sucrose and lactose

Question 39

polysaccharides

Answer 39

formed by combining many monosaccharides; loses water by the same process that forms disaccharides; includes glycogen, starches, and cellulose

Question 40

dehydration synthesis

Answer 40

bonds molecules together by removing water; | Glucose + Fructose 🡪 Sucrose + Water

Question 41

hydrolysis

Answer 41

reverses dehydration synthesis by adding water which dissolves any bonds created; Water + Sucrose 🡪 Glucose + Fructose

Question 42

lipids

Answer 42

- used as energy by the body - stored in fat tissue for future energy needs - can act as a chemical messenger, insoluble in water - typically hydrophobic - four classes of lipids: neutral fats, phospholipids, steroids, eicosanoids

Question 43

neutral fats

Answer 43

also called triglycerides, consists of a single glycerol and three fatty acid molecules

Question 44

saturated fatty acids

Answer 44

have single-bonds between all hydrocarbon chains

Question 45

unsaturated fatty acids

Answer 45

have one or more double-bonds between all hydrocarbon chains

Question 46

phospholipids

Answer 46

- like triglycerides, phospholipids contain a glycerol backbone - consists of a single glycerol, two fatty acid molecules, and a phosphate group Phosphate group: Polar and hydrophilic, can interact with water Fatty acid pair: Non-polar and hydrophobic, can only interact with other lipids

Question 47

phospholipid bilayer

Answer 47

makes up cell membranes, prevents organelles from diffusing out of the cell as well as preventing unwanted substances from entering.

Question 48

steroids

Answer 48

- contains four rings of carbon atoms - non-polar and lipid-soluble - cholesterol is a type of modified steroid (sterol) essential for the synthesis of bile salts and for providing structural support to cellular membranes

Question 49

eicosanoids

Answer 49

- formed from a 20-carbon fatty acid called arachidonic acid | - consists of two principle subclasses: prostaglandins, leukotrienes

Question 50

proteins

Answer 50

- Most abundant molecule in the body - Provides much more functions than carbohydrates or lipids: - Structural support (e.g. collagen, keratin) - Regulatory support (e.g. insulin) - Immunological (e.g. antibodies and interleukins) - Transportation (e.g. hemoglobin) - Catalytic (e.g. enzymes)

Question 51

amino acids

Answer 51

- Amino acids: Essential building blocks of proteins. - Contains an amino group, a carboxyl group, and a side chain, all attached to a single carbon atom. - When proteins are synthesized, two amino acids form a covalent bond called a peptide bond. This pair of amino acids is called a dipeptide. Three amino acids form a tripeptide, four forms a tetrapeptide, and so on.

Question 52

enzyme

Answer 52

- Conducts chemical reactions with very minimal energy usage. - Enzymes are the body’s catalysts. - The substance that an enzyme acts upon is called a substrate. - Enzymes are highly specific and only works on specific substrates. - lock-and-key mechanism e.g. lipase, amylase, trypsin

Question 53

nucleic acids

Answer 53

Consists of two classes: - Deoxyribonucleic acids - Ribonucleic acids The building blocks of nucleic acids are nucleotides.

Question 54

ATP

Answer 54

- Adenosine triphosphate is the ’energy currency’ of all living systems - Stores energy and releases them upon breakdown (exergonic catabolic reaction) - ATP functions: - muscle contractions - movement of chromosomes during cell division - transporting and diffusing substances cross membranes - synthesizing larger molecules from smaller ones - etc.