Ch 8--The role of Energy & Enzymes in Reactions

Question 1

What is Metabolism?

Answer 1

totality of reactions in the body.

Question 2

…. is the break down complex substances into simpler ones= releasing energy. ex: starch=glucose during cellular respiration
-releases ATP through the breakdown of carbs, proteins, and lipids

Answer 2

Catabolism

Question 3

What is Anabolism?

Answer 3

it is building complex substances from simpler ones- ex: building proteins from amino acids inside cells after respiration
- needs ATP for detoxification & thermogenesis

Question 4

Thermodynamics is the relationships between… and their transformations from…

Answer 4

all forms of energy…one form to another

Question 5

Energies exist in various forms such as:

Answer 5

potential, kinetic, heat, and chemical

Question 6

What is Potential energy?

Answer 6

is the one that a system possesses due to its position.

Question 7

What is Kinetic energy?

Answer 7

is the one that a system possesses due to motion

Question 8

-K.E. of atom/molecules
- is the result of the K.E. of atoms & molecules that causes them to move in random directions

Answer 8

Heat energy

Question 9

…. is P.E. of electrons released during…. reactions

Answer 9

Chemical energy….chemical

Question 10

The study of Thermodynamics is what?

Answer 10

energy can be transformed from one to another

Question 11

-Principle of Conservation of Energy
-Energy can neither be created nor destroyed, only transferred or transformed
-the energy of the universe remains constant

Answer 11

First Law of Thermodynamics

Question 12

The Second Law of Thermodynamics is what?

Answer 12

There is an increase in the entropy of the universe for every transformation or transfer of energy. It leads to the unavailability of a system’s energy to do work.

Question 13

What is Entropy?

Answer 13

chaos of molecules

Question 14

What is G?

Answer 14

Free energy

Question 15

Free energy is energy of a system that is….

Answer 15

capable of doing work

Question 16

What are the two equations to calculate change in free energy?

Answer 16

ΔG=ΔH-TΔS or ΔG=g2-G1

Question 17

ΔH is what?

Answer 17

change in enthalpy (total energy)

Question 18

ΔS is what?

Answer 18

Change in entropy (disorder)

Question 19

T is what?

Answer 19

Temperature in Kelvin (unit)

Question 20

G2 is free energy of products=

Answer 20

final energy of the system

Question 21

G1 is free energy of reactants=

Answer 21

initial energy of the system

Question 22

If G1 is greater than G2 meaning….

Answer 22

the system is unstable (negative), capable of doing work (more free energy)

Question 23

ΔG is negative=… excess energy will be released in the surrounding-….

Answer 23

spontaneous in nature; happens without input energy…. exergonic reaction

Question 24

If G2 exceeds G1….

Answer 24

The system is now stable (positive), work has been done- endergonic reaction= non-spontaneous

Question 25

Energy as ATP

Answer 25

is an energy molecule capable of releasing energy stored within its bonds, to carry out anabolic reactions {endergonic}

Question 26

What is Endergonic Reactions?

Answer 26

they harness that energy from the breakdown of ATP

Question 27

After hydrolysis ATP breaks down into what and it releases what?

Answer 27

ADP + Pi... it releases the potential energy stored in its bond to carry out Anabolic reactions in the cell

Question 28

What fuels the reaction to combine ADP & Pi to make ATP?

Answer 28

Catabolism

Question 29

What are Enzymes?

Answer 29

Proteins that act as catalyst & speed up chemical reactions

Question 30

How do enzymes speed up chemical reactions?

Answer 30

by lowering the activation energy barrier

Question 31

What is Activation Energy?

Answer 31

energy required by both spontaneous + non-spontaneous reactions in order to proceed & overcome the energy barrier

Question 32

What is the activation energy barrier?

Answer 32

its the impediment the reactants need to overcome to become products.

Question 33

How many times can an Enzyme lower the Ea Barrier?

Answer 33

4 ways

Question 34

1. An enzyme would orient the substrates correctly while....

Answer 34

binding them to their active sites

Question 35

2. An enzyme would...so they could be broken down faster into products

Answer 35

strain the bonds within substrates

Question 36

3. an enzyme would covalently bind to.... for a quick disintegration of substrate within itself.

Answer 36

the substrate and strengthen it s hold on it

Question 37

4. An enzyme is also capable of... to the substrates for efficient conversion into products

Answer 37

providing a micro favorable environment

Question 38

What are effects that enzyme activity cause?

Answer 38

1. general environmental factors, temp. & pH 2. chemicals such as cofactors + inhibitors

Question 39

What are cofactors and what are the two types?

Answer 39

they are enzyme helpers & may be inorganic or organic.

Question 40

What is an inorganic cofactor?

Answer 40

they are metals in ionic form

Question 41

What is an organic cofactor?

Answer 41

they are those that have carbon in their structure (these are coenzymes)

Question 42

Competitive Inhibitors are what?

Answer 42

they COMPETE with the substrate for the active site & if successful they bind to the active site of an enzyme & thereby blocking substrate from binding there

Question 43

Non-competitive Inhibitors are what?

Answer 43

DO NOT COMPETE for the active site but instead bind to another part of an enzyme resulting in the distortion of the active site & hence making it ineffective

Question 44

A cell's metabolic pathway is tightly regulated to prevent both shortage & surplus of products by keeping reactions in check is?

Answer 44

Allosteric Regulation

Question 45

Allosteric Regulation may either stimulate or inhibit what?

Answer 45

an enzyme's activity, depending on whether the substance bound to the enzyme is an active or an inhibitor

Question 46

The process by which the end product of a metabolic pathway acts as an inhibitor for an enzyme to shut down that same pathway, so no more end product is made is....

Answer 46

Feedback Inhibition

Question 47

Feedback Inhibition prevents...

Answer 47

wasting resources

Question 48

Negative feedback loop is....

Answer 48

a product should not be synthesized any longer when it is beyond the required amount