Chapter 13 (Book) Intro & Energy Carriers/e- Transport

Question 1

the energy to build cells comes from _______ _______

Answer 1

chemical reactions

Question 2

enzymes direct the transfer of energy onto _______ such as ___

Answer 2

carriers, ATP

Question 3

catabolism

Answer 3

breaking down complex molecules into smaller ones to yield energy

Question 4

organotrophy

Answer 4

organic compounds donate e- to yield energy

Question 5

heterotroph

Answer 5

organism that uses preformed organic compounds for biosynthesis

Question 6

lithotrophy

Answer 6

inorganic compounds donate e- to yield energy

Question 7

phototrophy

Answer 7

light absorption provides e- to yield energy

Question 8

photoautotrophy vs. photoheterotrophy

Answer 8

photoautotrohpy: light absorption drives CO2 fixation
photoheterotrophy: light absorption w/o CO2 fixation

Question 9

anabolism

Answer 9

building larger molecules from smaller ones

Question 10

definition of energy

Answer 10

the ability to do work

ex. flagellar propulsion, maintain ion gradients

Question 11

entropy

Answer 11

the disorder/randomness of the universe

always increasing

Question 12

ultimately, the cell’s energy is spent as _____

Answer 12

heat

ex. compost pile 60C

Question 13

Gibbs free energy change (deltaG)

Answer 13

deltaG = deltaH - TdeltaS

predicts whether a reaction will go forward

shows much much energy is potentially available to do work

Question 14

negative vs. positive deltaG

Answer 14

negative: the reaction will go forward
positive: the reaction goes in reverse

Question 15

enthalpy deltaH

Answer 15

heat energy absorbed or released

negative: released
positive: absorbed

Question 16

entropy deltaS

Answer 16

negative: decrease in entropy
positive: increase in entropy

Question 17

do we want deltaS to be negative or positive?

Answer 17

positive so it makes deltaG more negative

Question 18

in general a reaction yields energy for the cell if 2 things

Answer 18

products are more stable than reactants

entropy increases

Question 19

calorimeter

Answer 19

measures amount of energy (heat) released by a reactions

Question 20

intrinsic properties of the reaction that affect deltaG

Answer 20

enthalpy

entropy

Question 21

concentrations/environmental factors that affect deltaG

Answer 21

excess reactants makes deltaG more neg

temp, pressure, ionic strengths

Question 22

deltaG not prime standard conditions

Answer 22

298K (25C)

1 atm

1M (molar concentrations)

Question 23

the ______ of energy change is central to all living metabolism

Answer 23

additivity

coupling an energy-yielding rxn to an energy-spending one

Question 24

how is deltaG related to deltaG not

Answer 24

delta G = deltaG not + RTln[products]/[reactants]

R = 8.315x10^-3 kj/(mol*K)

Question 25

what is deltaG at equilibrium

Answer 25

0

Question 26

syntrophy

Answer 26

metabolic relationship between two species near-zero anaerobic pathways

Question 27

the random distribution of molecules at steady concentration represents the state of greatest _______

Answer 27

entropy

Question 28

entropy favors movement of nutrients from ______ to _______ concentration

Answer 28

higher, lower diffusion

Question 29

in most environments the concentration of nutrients outside the cell is lower than inside the cell...

Answer 29

so the cell must use energy to transport nutrients into the cell, lowering entropy

Question 30

3 energy carriers

Answer 30

ATP NADH FADH2

Question 31

what are energy carriers

Answer 31

molecules that gain and release small amounts of energy in reversible reactions transfer energy

Question 32

electron donor

Answer 32

a molecule that donates electrons to another molecules aka. reducing agent

Question 33

electron acceptor

Answer 33

a molecule that accepts electrons aka. oxidizing agent

Question 34

3 parts of ATP

Answer 34

base (adenine) sugar (ribose) 3 phosphates

Question 35

ATP complexes with ___

Answer 35

Mg2+ partially neutralizes negative charges of ATP phosphates to stabilize

Question 36

ATP is formed from ADP by __________

Answer 36

phosphorylation ADP + Pi + H+ --> ATP + H2O deltaGnot prime = 31 kj/mol

Question 37

3 ways ATP can transfer energy to cell processes

Answer 37

hydrolysis of Pi hydrolysis of PPi --> 2Pi phosphorylation of an organic molecule

Question 38

phosphotransferase system (PTS)

Answer 38

couple phosphorylation of a sugar to its transport across the cell membrane

Question 39

how much ATP is made through complete oxidation of glucose

Answer 39

38 ATP

Question 40

how efficient is complete oxidation of glucose

Answer 40

40-50%

Question 41

what does NADH stand for and what is it used for

Answer 41

nicotinamide adenine dinucleotide carry e- from breakdown products of glucose

Question 42

why is NAD+ relatively stable

Answer 42

aromatic ring delocalizes e-

Question 43

electron transport system/chain (ETS)

Answer 43

stores energy from e- transfer as an ion gradient across the cell membrane or an organelle enables production of ATP, motility, nutrient transport

Question 44

terminal electron acceptor

Answer 44

e- are transferred to this, and the product leaves the cell

Question 45

3 reasons why different reactions use different e- carriers

Answer 45

different redox levels different amounts of energy regulation and specificity

Question 46

what is the rate of a reaction determined by

Answer 46

activation energy (Ea)

Question 47

what is activation energy

Answer 47

the input energy required to generate the high-energy transition state on the way to products

Question 48

catalyst

Answer 48

an agent that lowers Ea and isn't consumed by the rxn

Question 49

enzyme

Answer 49

a protein catalyst that lowers Ea by bringing substrates close to each other and correctly orienting them

Question 50

allosteric site

Answer 50

site on an enzyme that is not the substrate binding site binding induces a conformational change that increases the rate of the rxn

Question 51

what is the direction of catalysis of an enzyme dependenton

Answer 51

the concentrations of reactants and products the presence of absence of allosteric regulators