2.9 Thermodynamics and Metabolism

Question 1

What is an anabolic reaction? Example?

Answer 1

A metabolic reaction requires and input of energy because it builds larger molecules from smaller molecules.

for example, the building of glucose by plants during photosynthesis.

Question 2

What is a catabolic reaction?

Answer 2

A metabolic reaction that release energy by breaking apart larger molecules such as carbohydrates, lipids, proteins, and fat into smaller molecules or their subunits

Question 3

What is metabolism?

Answer 3

The sum of all anabolic and catabolic reactions in a cell and organism

Question 4

what is potential energy converted into? Example in terms of glucose?

Answer 4

useful free energy in the form of ATP that can do work

Ex the potentially energy stored in the bonds in glucose break to make ATP

Question 5

What does the first law of thermodynamics state? example?

Answer 5

Energy can not be created nor destroyed, only converted from one form to another

If a process in the body appears to gain (or need) energy, it does so at the expense (or release) of energy somewhere else in the body.

Ex, when work is done in the cells of the body, energy, is transformed from one type of energy to another

Question 6

What is chemical potential energy?

Answer 6

Stored energy that has the potential to do work

Question 7

Why is reaction coupling important?

Answer 7

It’s the reason all reactions in the body are able to work

• the foundation of metabolism

Question 8

What is entropy?

Answer 8

Entropy is the measure of randomness of disorder in a collection of molecules

Question 9

When is entropy increased?

Answer 9

When large molecules are broken down into smaller molecules

Question 10

What is the second law of thermodynamics states?

Answer 10

The entropy of the universe increases with any change that occurs

Question 11

Exergonic reaction products vs reactants energy amount

Answer 11

Products have less free energy than the reactants

Question 12

Endergonic reaction reactant vs products? why?

Answer 12

-Products have more free energy than the reactants

-The reactants absorb energy which means that the products have more energy than the reactants.

Question 13

What is free energy in terms of reactants and products

Answer 13

the potential energy difference between reactants and products

Question 14

How do living organisms violate the second law of thermodynamics?

Answer 14

by building highly order structures

-ex a tree seed growing into a tree

Question 15

matter

Answer 15

anything that has mass and takes up space examples cells in the body are matter

Question 16

energy

Answer 16

-the ability to do work

Question 17

what are the two types of energy?

Answer 17

potential energy and kinetic energy

Question 18

potential energy

Answer 18

the energy held by an object due to its position or the arrangement of its atoms

for example, a rock about to fall off a cliff has high potential energy because there is a lot of distance between the rock and the ground

Question 19

kinetic energy

Answer 19

the energy an object has in motion

Question 20

redox reaction

Answer 20

oxidation and reduction occurring together
oil rig

oxidation loses electrons, reduction gains electrons

Question 21

why is photosynthesis an endergonic reaction?

Answer 21

requires the net input of Free Energy because it decreases Entropy by building glucose molecules

Question 22

how is reaction coupling used in photosynthesis?

Answer 22

The same amount of energy needed by photosynthesis is provided by cellular respiration. cellular respiration is coupled with the energy needed

Question 23

what is the entire basis of metabolism?

Answer 23

reaction coupling

Question 24

what does cellular respiration use to break chemical bonds in glucose? what does this do?

Answer 24

Cellular Respiration uses oxygen to break the chemical bonds in glucose. This releases the chemical potential energy that is stored in the bond.

Question 25

what is the product of cellular respiration

Answer 25

ATP

Question 26

what is the chemical potential energy held in glucose bonds converted into?

Answer 26

This Chemical Potential Energy is converted into the Electrochemical Potential Energy needed to build concentration gradients of H+ ions across the cell membrane via Active Transport because active Transport is an energy-requiring process

Question 27

how is the second law of thermodynamics satisfied within metabolism?

Answer 27

every highly ordering ANABOLIC process is always COUPLED with a highly degrading CATABOLIC process that increases disorder, and OVERALL there is a net increase in disorder and the Second Law of Thermodynamics is satisfied.

Question 28

why is energy not converted 100 percent along the way?

Answer 28

there is heat lost to the environment

Question 29

is heat ordered or disordered energy?

Answer 29

-heat is disorder energy

-When it is released to the environment, it speeds up the random movement of atoms and molecules in its path.

Question 30

are bonds ordered or disordered energy? why?

Answer 30

ordered energy

-breaking of chemical bonds never releases energy to the external environment. Energy is only released when chemical bonds are formed.

Question 31

what is Gibbs free energy?

Answer 31

the portion of a system energy that can perform work

Question 32

what is ATP?

Answer 32

the energy currency of cells

Question 33

how does ATP release its energy?
how is this energy used?

Answer 33

-when its phosphate bonds are broken

-this energy is used to drive the endergonic reaction of cells

Question 34

how does ATP convert to ADP and Pi?

Answer 34

adding water to ATP hydrolyzes ATP to break it apart. One of the phosphates are lost to create organic phosphate and ADP

Question 35

what is the chemical equation for the breakdown of ATP?

Answer 35

ATP + H2O –> ADP + Pi

Question 36

why can’t the energy released by cells not be converted to heat? what do cells do instead?

Answer 36

in living cells, the energy that is released cannot be converted to heat or else it will burn the cell. Instead, cellular processes that release energy are coupled with cellular processes that require energy

Question 37

how does reaction coupling work?

Answer 37

the products of one reaction become the reactants of another reaction

Question 38

what do all metabolic processes have in common?

Answer 38

they are enzyme-catalyzed and reversible