Biology 1001A Lecture Notes - Lecture 16: Endergonic Reaction, Thermodynamics

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emeraldcattle11

7 May 2018

School

Western University

Department

Biology

Course

Biology 1001A

Professor

Beth Mac Dougall- Shackleton

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Energy  Capacity to do Work

Types:

1) Kinetic Energy: Energy possessed by an object because of its motion

2) Potential Energy: Energy stored in an object due to its position or chemical structure

Why contributes to the potential energy of a molecule?  The chemical energy in a molecule has to do

with the position of electrons in its atoms. (The further an electron is from the nucleus of an atom, the

greater potential energy that electron possesses).

Isolated System: does not exchange matter or energy with its surroundings. (e.g. thermos).

Closed System: can exchange energy, but not matter, with its surroundings. (e.g. earth- releases heat

energy, but no matter).

Open System: both energy and matter can move freely between the system and the surroundings. (e.g.

the ocean).

First Law of Thermodynamics: Energy can be transformed from one form into another or transferred

from one place to another, but it cannot be created or destroyed. (Principle of the conservation of

energy).

Second Law of Thermodynamics: The total disorder (entropy) of a system and its surroundings always

increases. Entropy is a measure of how much energy as flowed from being localized to becoming more

widely dispersed (how spread out energy is).

Free Energy and Spontaneous Processes

1. Reactions tend to be spontaneous if they are exothermic (the chemical energy in products are

less than the chemical energy in the reactants because the electrons in the products are more

tightly held to the atoms in the molecules)

2. Reactions tend to be spontaneous when the entropy of the products is greater than the entropy

of the reactants (entropy increases when the number of molecules increases or a phase change

occurs from s  l  g)

The change in free energy determines whether a process is spontaneous or not

ⵠG = ⵠH - TⵠS  Change in Gibbs Free Energy is equal to the change in enthalpy minus the change in

entropy x temperature (in K). A spontaneous (exergonic) reaction is one where the free energy of the

products is less than the free energy of the products (ⵠG <0). A nonspontaneous (endergonic) reaction

is one where the free energy of the products is greater than the free energy of the reactants meaning

energy must be put into the process to make it happen. (ⵠG>0).

Many processes do not reach completion, but rather equilibrium. As a system moves toward

equilibrium, the free energy of the system becomes lower and reaches its lowest point when the system

is at equilibrium (at maximum stability, the system cannot do work and ⵠG=0). The more negative ⵠG is

for a process, the farther towards completion the reaction will move before equilibrium is established.

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Document Summary

Types: kinetic energy: energy possessed by an object because of its motion, potential energy: energy stored in an object due to its position or chemical structure. The chemical energy in a molecule has to do with the position of electrons in its atoms. (the further an electron is from the nucleus of an atom, the greater potential energy that electron possesses). Isolated system: does not exchange matter or energy with its surroundings. (e. g. thermos). Closed system: can exchange energy, but not matter, with its surroundings. (e. g. earth- releases heat energy, but no matter). Open system: both energy and matter can move freely between the system and the surroundings. (e. g. the ocean). First law of thermodynamics: energy can be transformed from one form into another or transferred from one place to another, but it cannot be created or destroyed. (principle of the conservation of energy). Second law of thermodynamics: the total disorder (entropy) of a system and its surroundings always increases.

Related Questions

Question 1 When energy changes from one form to another, some of the energy that can be used to do work is always lost. The loss of this energy is mostly in the form of _________.
a. heat
b. potential energy
c. kinetic energy
d. light energy
e. mechanical energy

Question 2 Which of the following is exergonic?
a. binding fatty acids and glycerol molecules together to form lipids
b. building proteins from amino acids
c. binding sugars molecules together to form glycogen
d. breaking bonds in starch to release glucose
e. adding a phosphate group to ADP to form ATP

Question 3 The first law of thermodynamics states that:
a. energy can neither be created nor destroyed.
b. the universe is increasing in entropy.
c. all living organisms must eat to derive energy.
d. energy is required to bring molecules into a cell against a concentration gradient.
e. in energy-yielding reactions, matter goes from a more-ordered to a less-ordered state.

Question 4 Which of the following is true of energy?
a. It can be transferred from one form to another with 100 percent efficiency.
b. It can be created.
c. It can be stored in chemical bonds.
d. It can never be stored.
e. It can be released by forming chemical bonds.

Question 5 Metabolism is:
a. the sum of all the energy a cell uses.
b. the sum of all the vitamins a cell contains.
c. the sum of all the enzymes a cell contains.
d. the sum of all the chemical reactions that an organism carries out.
e. the sum of all the ATP a cell contains.

Question 6 Entropy is the measure of ________ in a system.
a. disorder
b. order
c. energy
d. work
e. heat

Question 7 What percentage of the energy stored in glucose are humans cells able to use to do useful work?
a. 37%
b. 100%
c. 15%
d. 52%
e. 48%

Question 8 What is activation energy?
a. the energy gained by living things, allowing them to remain active
b. the energy produced by the breakdown of ATP to ADP.
c. the energy required to initiate or begin a chemical reaction
d. the energy created by enzymes during exergonic reactions
e. the energy lost by living things in the form of heat

Question 9 Which of the following is true of allosteric enzymes?
a. Their activity can be reduced when the product binds the enzyme.
b. Their activity can be reduced when a coenzyme binds to them.
c. Their activity can be reduced when the substrate binds the enzyme.
d. Their activity can be increased when the product binds the enzyme.

Question 10 Which of the following is a true statement about enzymes?
a. They are made of proteins.
b. They are altered by the reactions they catalyze.
c. They increase the energy of activation of chemical reactions.
d. All of the above are true.
e. None of the above is true.

Question 11 What is the energy currency of cells?
a. ADP
b. enzymes
c. glucose
d. vitamins
e. ATP

Question 12 Kinetic energy is ____________, while potential energy is _____________.
a. stored energy; energy that is being used
b. stored energy; energy that can't be used
c. energy that is being used; stored energy
d. energy that can't be used; stored energy

Question 13 The energy released during ________ reactions can be used to drive ________ reactions, and this is called ________ reactions.
a. exergonic; endergonic; coupled
b. endergonic; exergonic; coupled
c. exergonic; endergonic; mutually dependent
d. coupled; mutually dependent; independent
e. endergonic; exergonic; mutually dependent

Question 14 ADP + P + Energy --> ATP Which of the following is a true statement about the chemical reaction above?
a. This is a coupled reaction.
b. This is an exergonic reaction.
c. The product of the reaction contains more energy than that of all of the reactants combined.
d. This is an endergonic reaction.
e. This is an example of a catabolic reaction.

greychimpanzee211

As entropy increases there will be more useful energy to doâworkâ. True or false?

False. As entropy increases, there will generally be less usefulenergy to do work. We can think of entropy as usually being presentin the form of heat energy. Imagine a car motor, which attempts toturn chemical potential energy into kinetic energy (movement). Lessefficient motors will get hotter for the same amount of fuelconsumed. When you drive a car you hope that most of the fuelenergy is converted into kinetic energy and not lost as heat(entropy). The hotter the car (and thus the more entropy) the lessefficient the ability to do âworkâ (the moving of the vehicle).

True. As entropy increases, there will generally be more usefulenergy to do work. We can think of entropy as usually being presentin the form of heat energy. In most biological and mechanicalsystems it is heat energy which is captured to do useful 'work'.Heat energy, the random movement of molecules, and increases inentropy are central to doing useful work.

Biological systems sometimes appear on the surface to break theSecond Law of Thermodynamics â by seemingly increasing the order inthe overall system. They donât. Why?

a. Earth (and living things on it) are not a closed system. Thesun's constant input of energy in the form of photons is harnessedby living things to create internal order within themselves. Butwithout such a constant input of energy, most biological systems onearth would break down.

b. The Second Law tells us that no natural process can occurunless it is also associated with an increase in the entropy of theuniverse. A living organism (such as an animal or plant) brings inmatter and energy from its environment and uses this to creategreater order within its body: the processes of life. But it isimportant to keep in mind that all animals and plants are also partof a larger system of the environment around them. While creating asmall âpocketâ of order, the processes of life (metabolism,movement, etc..) releases heat into the environment â thusincreasing the entropy of the universe and following the2^nd law.

c. Living things, by harnessing energy to create order (withinand around themselves) actually create a paradox in questionssurrounding the first and second laws of thermodynamics andseemingly violate many previously held assumptions.

d. Both a and b above are correct.

When plants capture energy in the photons of sunlight andconvert that energy into the chemical bonds of organic molecules,are they creating new energy?

No, the energy is being transferred from one form into another.But no new energy is being created.

No, the overall total energy is decreasing over time.

Yes, by capturing photons, the plants are creating newenergy.

Yes, by capturing photons, the plants are creating new energy -of a different wavelength.

ceruleanhamster867

......Use the following to feel out the sentense: cycled, photosynthesis, cellular respiration, oxygen, carbon dioxide, ATP

During ____________ , mitochondria break down carbohydrates to produce energy that is used to make ____________ .

This process requires ____________ and carbohydrates, and produces ____________ and water.

During ____________ , chloroplasts use water and ____________ to create carbohydrates.

This process requires ____________ and water, which are byproducts from ____________ .

In turn, it produces ____________ and carbohydrates that are used in ____________ .

In this manner, the flow of energy is ____________ between chloroplasts and mitochondria.

..........use the following to feel out each sentense: from, oxidized, photosynthesis, cellular respiration, gains, to, loses, reduced.

During ____________ , hydrogen atoms are transferred ____________ water ____________ carbon dioxide as glucose forms.

Thus, during ____________ , carbon dioxide is ____________ , while water is ____________ . In other words, carbon dioxide ____________ electrons and water ____________ electrons.

During ____________ , glucose is ____________ as oxygen is ____________ , becoming water.

In each of these reactions, while one molecule loses electrons (is ____________ ), another gains electrons (is ____________ ); thus, each of these metabolic pathways includes redox reactions: coupled reduction and oxidation reactions.

..........use the following to feel out the sentenses: increase, conservation of energy, first of thermodynamics, input, decrease, laws of thermodynamics, secod law of thermodynamics, heat

The ____________ explain energy flow and energy conservation and can be applied to biological systems.

The ____________ states that energy cannot be created or destroyed, also known as the law of ____________ .

The ____________ states that energy is lost when it is converted from one form to another, often in the form of ____________ .

As cells go through transformations, they ____________ the total entropy of the universe, resulting in a ____________ in available energy.

For example, photosynthesis in plants requires an energy ____________ to turn carbon dioxide and water into sugar because there is a ____________ in entropy.

Biology 1001A Lecture Notes - Lecture 16: Endergonic Reaction, Thermodynamics

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