Chapter 13 - Exam 3

Question 1

Autotroph

Answer 1

use CO2 from the atmosphere as their sole source of carbon

Question 2

Heterotroph

Answer 2

cannot use atmospheric CO2 and must obtain carbon from their outside environment

Question 3

Metabolism

Answer 3

the chemical reactions in the organism

Question 4

Metabolites

Answer 4

series of intermediates through which precursors are converted to products

Question 5

Intermediary Metabolism

Answer 5

the combined activities of all the metabolic pathways that interconvert precursors, metabolites, and products of low molecular weight

Question 6

Catabolism

Answer 6

the degradative phase of metabolism (releases energy)

Question 7

Anabolism

Answer 7

the building phase of metabolism (requires energy)

Question 8

What is ΔG?

Answer 8

expresses the amount of energy capable of doing work during a reaction at constant temperature and pressure

Question 9

What is ΔH?

Answer 9

enthalpy (the heat content of the reacting system)

Question 10

What is ΔS?

Answer 10

entropy (randomness or disorder in a system)

Question 11

If ΔG is negative, then the reaction

Answer 11

proceeds foward

Question 12

If ΔG is positive, then the reaction

Answer 12

proceeds in reverse

Question 13

Understand how reactions are thermodynamically coupled

Answer 13

thermodynamically unfavorable reactions can be coupled to favorable reactions (often involves coupling to ATP hydrolysis)

Question 14

Homolytic Cleavage

Answer 14

cleavage of a covalent bond where each atom leaves the bond as a radical, carrying one unpaired electron

Question 15

Heterolytic Cleavage

Answer 15

cleavage of a covalent bond where one atom retains both bonding electrons (more common)

Question 16

Nucleophiles

Answer 16

functional groups rich in and capable of donating electrons

Question 17

Electrophiles

Answer 17

electron-deficient functional groups that seek electrons (carbon can act as either a nucleophile or electrophile)

Question 18

Carbanion

Answer 18

negatively charged carbon atom

Question 19

Carbocation

Answer 19

positively charged carbon atom

Question 20

Rearrangements, isomerization, and eliminations

Answer 20

redistribution of electrons results in alteration without changes in the overall oxidation state of the molecule

Question 21

Rearrangements can be

Answer 21

substitution, addition, or elimination reactions

Question 22

Free Radicals

Answer 22

homolytic cleavage of covalent bonds to generate free radicals

Question 23

Group Transfers

Answer 23

the transfer of acyl, glycosyl, and phosphoryl groups from one nucleophile to another (acyl group transfer involves the addition of a nucleophile to the carbonyl carbon of an acyl group to form tetrahedral intermediate)

Question 24

Oxidation

Answer 24

loses electrons

Question 25

Reduction

Answer 25

gains electrons

Question 26

Standard Reduction Potential (ΔE)

Answer 26

a measure (in volts) of the relative affinity of the electron acceptor of each redox pair for electrons

Question 27

Positive Standard Reduction Potential (ΔE)

Answer 27

takes electrons

Question 28

Negative Standard Reduction Potential (ΔE)

Answer 28

donates electrons

Question 29

Understand the relationship between the standard reduction potential ΔE and ΔG

Answer 29

when ΔE is greater than 0, then ΔG is less than 0 (inverse relationship), and the reaction is thermodynamically favored; vice versa