Energy and Glycolysis

Question 1

thermodynamics

Answer 1

the study of energy transformations

Question 2

1st law of thermodynamics

Answer 2

energy can be transferred and or transformed, but it cannot be created or destroyed (principle of conservation of energy)

Question 2

exergonic

Answer 2

proceeds with a net release of free energy and is spontaneous; G is negative (reactants > products)

Question 2

entropy

Answer 2

measure of disorder, or randomness

Question 2

2nd law of thermodynamics

Answer 2

every energy transfer or transformation increases the entropy of the universe

Question 3

endergonic

Answer 3

absorbs free energy from its surroundings and is non spontaneous; G is positive (reactants<products)

Question 4

energy coupling

Answer 4

use of exergonic process to drive an endergonic one -> mediated by ATP

Question 4

three types of cell work

Answer 4

chemical, transport, mechanical

Question 5

ATP (adenosine triphosphate)

Answer 5

composed of ribose, adenine and three phosphate groups
- bonds can be broken by hydrolysis (energy released with bonds broken)
- chemical change to lower free energy state
- ATP + H2O -> ADP + Pi
- ATP cycle: catabolism and anabolism

Question 5

ATP drives endergonic reactions by…

Answer 5

phosphorylation: transferring a P group to some other molecule
- recipient is the phosphorylated intermediate
- leads to a change in a protein’s shape and often its ability to bind to another molecule
- renewable resource by addition of a phosphate group to ADP

Question 6

catalyst

Answer 6

a chemical agent that speeds up a reaction with out being consumed by the reaction

Question 7

an enzyme

Answer 7

a catalytic protein

Question 8

activation energy (Ea)

Answer 8

the initial energy needed to start a chemical reaction

Question 9

catalysis

Answer 9

speeds up reactions by lowering the Ea barrier

Question 10

enzyme’s substrate

Answer 10

the reactant that an enzyme acts on

Question 11

enzyme-substrate complex

Answer 11

enzyme binds to substrate

Question 12

active site

Answer 12

region on enzyme where substrate binds

Question 13

induced fit

Answer 13

enzyme change shape due to chemical interactions with the substrate

Question 14

the active site can lower the Ea barrier by…

Answer 14

• orienting substrates correctly
• straining substrate bonds
• providing a favorable microenvironment
• covalently bonding to the substrate

Question 15

enzyme saturation increase =

Answer 15

increased reaction speed = increased substrate concentration

Question 16

photosynthesis generates

Answer 16

O2 and organic molecules, used as fuel for cellular respiration
- cell uses chemical energy stored in organic molecules to regenerate ATP

Question 17

catabolic pathways yield energy by…

Answer 17

oxidizing organic fuels

Question 18

aerobic respiration

Answer 18

consumes organic molecules and O2 and yields lots of ATP (occurs without O2)

Question 19

cellular respiration

Answer 19

includes both aerobic and anaerobic processes
- requires fuel and oxygen

Question 19

fermentation

Answer 19

a partial degradation of sugars that occurs without O2

Question 20

redox reactions

Answer 20

chemical reactions that transfer electrons between reactants

Question 21

oxidation

Answer 21

loses electrons

Question 22

reduction

Answer 22

gains electrons

Question 23

reducing agent

Answer 23

electron donor

Question 24

oxidizing agent

Answer 24

electron acceptor

Question 25

potential energy stored...

Answer 25

in chemical bonds of sugar, protein and fat molecules - breaks bonds to make ATP

Question 26

NAD+ and NADH

Answer 26

the NAD+ picks up an electron from glucose, at which point it becomes NADH. Then NADH, along with another molecule flavin adenine dinucleotide (FADH2) will ultimately transport the electrons to the mitochondria

Question 27

electron transport chain

Answer 27

electrons passed to increasingly electronegative carrier molecules -series of redox reactions - electron transfer to oxygen = regenerates ATP

Question 27

stages of cellular respiration

Answer 27

glycolysis, citric acid cycle, oxidative phosphorylation

Question 28

glycolysis

Answer 28

breaks down glucose into 2 molecules of pyruvate in cytosol - can occur with or without O2

Question 29

pyruvate oxidative and citric acid cycle

Answer 29

complete breakdown of glucose in mitochondrial matrix

Question 30

oxidative phosphorylation

Answer 30

inner membrane of mitochondria and accounts for most of ATP synthesis (90%)

Question 31

substrate-level phosphorylation

Answer 31

small amount of ATP formed in glycolysis and the citric acid cycle

Question 32

glycolysis breaks down glucose into 2 pyruvate, has 2 major phases:

Answer 32

- energy investment phase (-2) - energy payoff phase (+4)

Question 33

net yield of glycolysis

Answer 33

2 ATP and 2 NADH per glucose molecule

Question 34

before the citric acid cycle can begin, pyruvate must be converted...

Answer 34

to acetyl CoA