Energy and Enzymes

Question 1

Define enzyme

Answer 1

a catalyst that speeds up chemical reactions

Question 2

what enzyme catalyses the removal of a phosphate group from most molecules

Answer 2

phosphotase

Question 3

What is the central mechanism for most intracellular communication

Answer 3

removal of a phosphate group

Question 4

What type of reactions do enzymes play a key role in

Answer 4

Metabolic reaction (eg. growth, reproduction, respond to stimuli, movement)

Question 5

Define energy

Answer 5

the capacity to do work or transfer heat

Question 6

what is the kinetic energy of electricity

Answer 6

flow of e-

Question 7

what is kinetic E

Answer 7

the E of movement; the E possessed by and object in motion

Question 8

Define potential energy

Answer 8

E stored in objects giving them the capacity for work; E an object has bc of its chemical structure or position

Question 9

Where is Ep stored within mlcls

Answer 9

within bonds between atoms of that moleculew

Question 10

As e- move closer to the atomic nucleus, the atom…

Answer 10

loses Ep

Question 11

What is the first law of thermodynamics

Answer 11

Energy can be transformed from one form to another but it cannot be created or destroyed

Question 12

what is the second law of thermodynamics

Answer 12

every energy transfer or transformation makes the universe more disordered or increases entropy

Question 13

define entropy

Answer 13

the tendency of energy to become dispersed and spread out

Question 14

Biological systems transfer E from what two main sources?

Answer 14

light and catabolism

Question 15

what is the main E driver in biological systems

Answer 15

photosynthesis

Question 16

define Catabolism

Answer 16

the chemical breakdown of organic and inorganic molecules

Question 17

define enthalpy

Answer 17

the heat content of a system (△H)

Question 18

△H=

Answer 18

△Hproduct - △Hreactant

Question 19

enthalpy reflects

Answer 19

the number and kinds of chemical bonds that exist between atoms

Question 20

what is the overall △H of an endothermic reaction

Answer 20

positive

Question 21

what is the overall △H of an exothermic rxn

Answer 21

negative

Question 22

define spontaneous rxn

Answer 22

a reaction in which free E of the products is less than free E of the reactants

Question 23

Spontaneous rxns tend to occur when…

Answer 23

a) reactions are exothermic

b) △Sproducts > △Sreactants

Question 24

Entropy is increased when…

Answer 24

a) chem rxns result in an increase to the number of mlcls

b) when solids turn to liquids or when liquids turn to gas

Question 25

Define free energy (△G)

Answer 25

the portion of a systems energy that can perform work when temperature is uniform throughout the system

Question 26

△G=

Answer 26

△H-T△S

Question 27

Define exergonic reaction

Answer 27

reaction where the free energy of the reactants ism greater than the free energy of the products

Question 28

in exergonic rxns, is△G neg or pos

Answer 28

neg

Question 29

are exergonic rxns energy consuming or energy releasing

Answer 29

energy consuming

Question 30

what is another term for spontaneous reaction

Answer 30

exergonic process

Question 31

define endergonic reaction

Answer 31

reaction where the free energy of the products is greater than the free energy of the reactants

Question 32

In endergonic reactions is △G pos or neg

Answer 32

pos

Question 33

are endergonic rxns energy consuming or energy releasing

Answer 33

consuming

Question 34

Do endergonic or exergonic rxns result in a higher state of free E

Answer 34

endergonic rxns

Question 35

what is the basis of an energy coupling rxn

Answer 35

production of E from exergonic rxn is available to run an endergonic rxn

Question 36

do rxns tend to be more spontaneous when △S is pos or neg?

Answer 36

pos

Question 37

define equilibrium

Answer 37

maximum stability of a rxn where △G=0, concentrations aren’t necessarily equal