GB1: Chapter 8

Question 1

Metabolism

Answer 1

Totality of organism’s chemical reactions; manages materials and energy resources of cell
is an emergent property due to the organized interactions between molecules

Question 2

Metabolic Pathway

Answer 2

certain molecule is changed in a series of defined steps, each catalyzed by enzyme, to make product

Question 3

Enzyme

Answer 3

macromolecule that speeds up chemical reaction (lowers activation energy of rxn)

Question 4

Catabolic pathways (w/ ex)

Answer 4

process that releases energy by breaking down complex molecules into simpler compounds
some bonds are broken/formed, releasing energy, products have lower-energy
- ex: cellular respiration (breaks down glucose and other organic fuels to get water and co2; the energy stored in the organic compounds now can be used)

Question 5

Anabolic pathways/biosynthetic pathways (w/ ex)

Answer 5

process that consumes energy to form complicated molecules from simpler ones
- ex: creation of polypeptide from amino acids

Question 6

bioenergetics

Answer 6

study of how energy flows through living organisms

Question 7

Energy

Answer 7

capacity to cause change/to do work/ability to rearrange collection of matter

Question 8

kinetic energy

Answer 8

energy of movement of objects (energy the object has due to its motion)

Question 9

Thermal energy

Answer 9

total kinetic energy of random movement of atoms/molecules

Question 10

Heat

Answer 10

transfer of thermal energy from one object to another

Question 11

Potential energy

Answer 11

energy that matter has due to its location or structure
(think of a dam; water has high potential energy because of its altitude above sea level)

Question 12

Chemical energy

Answer 12

potential energy available for release in chemical reaction

Question 13

Thermodynamics

Answer 13

study of energy transformation occurring in collection of matter

Question 14

kinetic energy to potential energy example divers

Answer 14

kinetic energy of muscle movement is being transformed into potential energy as diver gets higher in altitude by climbing ladder

Question 15

system, surroundings, isolated system, open system

Answer 15

• system: matter under study
• surroundings: everything outside system
• isolated system: system cannot exchange matter/energy with surroundings
  -open system: system can exchange matter/energy with surroundings

Question 16

organisms are what kind of system?

Answer 16

open system: they absorb energy (light energy or chemical energy via organic molecules) and then release heat and metabolic waste products (like co2) to surroundings

Question 17

1st law of thermodynamics/principle of conservation of energy

Answer 17

energy can be transferred and transformed, but it cannot be created or destroyed
(ex: plant acts as energy transformer bc it absorbs light energy and converts it to chemical energy)

Question 18

2nd law of thermodynamics

Answer 18

sum of entropies of system and surroundings (the universe) must always increase

Question 19

entropy

Answer 19

measure of molecular disorder/randomness
(more randomly arranged a collection of matter is = greater entropy)

Question 20

entropy in universe

Answer 20

increasing amounts of heat, less ordered forms of matter

Question 21

Spontaneous/energetically favorable process

Answer 21

process that leads to increase in entropy, doesn’t take an input of energy, is ENERGETICALLY FAVORABLE
some are instantaneous and some aren’t

Question 22

nonspontaneous/nonenergetically favorable process

Answer 22

process that leads to decrease in entropy, requires an INPUT of energy
however, some of that input of energy is lost as heat which also increases entropy into surroundings in universe as a whole

Question 23

Increase in organization…

Answer 23

does not go against 2nd law of thermodynamics of continual increase in entroy

Question 24

Gibbs free energy

Answer 24

portion of system’s energy that can do work when temperature/pressure are uniform throughout system

deltaG = deltaH - TdeltaS

deltaH = enthalpy (total energy)
deltaS = entropy (measure of how energy is distributed in a system)
T = temp. in K

delta G = Gfinal - Ginitial

Question 25

energetically favorable/spontaneous reactions for gibbs

Answer 25

delta G is negative (deltaH is negative or deltaS is positive, or both) every spontaneous process decreases the system's free energy

Question 26

+ deltaG or 0 delta G =

Answer 26

+ deltaG = nonspontaneous (not energetically favorable) 0 deltaG = never spontaneous

Question 27

system + surroundings

Answer 27

= universe

Question 28

entropy + analogy

Answer 28

there is always tendency for higher entropy bedroom over time gets messy, doesn't suddenly become neat

Question 29

exergonic reaction

Answer 29

proceeds with net release of free energy since system lost energy, deltaG is - and rxn is spontaneous/energetically favorable

Question 30

In larger scale, energy flows into ecosystems in... and exits in...

Answer 30

the form of light; the form of heat

Question 31

3 main things cell does

Answer 31

chemical work transport work mechanical work

Question 32

chemical work

Answer 32

pushing endergonic reactions that would not occur spontaneously

Question 33

transport work

Answer 33

pumping of substances across membranes against direction of spontaneous movement

Question 34

mechanical work

Answer 34

beating of cilia, contraction of muscle cells, movement of chromosomes during cell division

Question 35

energy coupling

Answer 35

use of exergonic process to drive endergonic one (overall process would be exergonic)

Question 36

ATP adenosine triphosphate

Answer 36

sugar ribose nitrogenous base adenine 3 phosphate group chain

Question 37

hydrolysis of ATP

Answer 37

hydrolysis of ATP with water yields energy, ADP, phosphate group release of energy is from chemical change of high free energy ATP to lower free energy of ADP

Question 38

energy is not found in the bonds themselves

Answer 38

the high energy found in especially phosphate groups is due to its higher energy relative to the products (ADP & phosphate group)'s lower energy

Question 39

Phosphorylation

Answer 39

transfer of phosphate group to molecule from ATP

Question 40

phosphorylated intermediate

Answer 40

molecule that got phosphorylated (has a phosphate group that was covalently bonded from ATP); has more free energy and less stable this is how exergonic and endergonic rxns are coupled!

Question 41

Glutamic acid conversion to glutamine

Answer 41

- is endergonic rxn so needs input of energy (+ deltaG) - Glutamic acid is phosphorylated by ATP, making it less stable with more free energy - now ammonia is able to bind to glutamic acid by displacing phosphate group, and ADP and phosphate group come out of reaction. now we have glutamine! - although deltaG was +, overall is -deltaG because of ATP hydrolysis (which has -deltaG). so with the help of ATP hydrolysis, the overall rxn is spontaneous

Question 42

ATP cycle

Answer 42

energy released by catabolic rxns is used to fuel energy needed to phosphorylate ADP to make ATP. then when ATP is hydrolyzed, it releases energy needed for anabolic reactions

Question 43

Activation energy

Answer 43

amount of energy needed to convert reactants to products, is supplied in the form of heat through thermal energy that reactants absorb from surroundings. This heat causes more collisions among substrates and enzymes, which increases the rate of the reaction

Question 44

catalysis

Answer 44

process where catalyst selectively speeds up a reaction without itself being consumed (alternative to heat since there's a limit to temperature for living organisms)

Question 44

transition state

Answer 44

when molecules have absorbed enough free energy, unstable and ready to break bonds

Question 45

can enzyme change nature of reaction?

Answer 45

NO. enzymes cannot make endergonic rxns exergonic, cannot change deltaG

Question 46

induced fit

Answer 46

tightening of binding after initial contact; enzyme shape changes slightly because of interactions between enzyme's active site amino acids and substrate's.

Question 47

mechanisms that enzymes use to speed up reactions

Answer 47

- proper orientation to make sure active site correctly binds to substrate in a way so that the right parts can interact and make a product - puts stress and bends on covalent bond of substrate to break bonds - provides different microenvironment suitable for specific rxn - temporarily covalently bond, usually with amino acids

Question 48

cofactors

Answer 48

nonprotein helpers for catalytic activities; usually for chemical processes like e- transfers -binds tightly to enzyme as or loosely to substrates -inorganic: metals -organic: vitamins - COENZYMES

Question 49

competitive inhibitors