Question 1

During photosynthesis, plants convert light energy to chemical energy. This is an example of

Accepted Answer

Photosynthesis is an example of the first law of thermodynamics, which states that energy cannot be created or destroyed, only transformed from one form to another. Here, light energy is converted into chemical energy.

Question 2

When, if ever, do molecules stop moving?

Accepted Answer

At absolute zero, molecular motion theoretically stops because the system is at its lowest energy state.

Question 3

Activation energy is necessary for all reactions.

Accepted Answer

Activation energy is required for all chemical reactions to proceed, regardless of whether they are endergonic or exergonic.

Question 4

Energy that is not converted to useful energy is usually given off as

Accepted Answer

Energy that is not converted to useful energy is typically dissipated as heat due to inefficiencies in energy conversion processes.

Question 5

Each of the following requires 12 carbon atoms. Which of the arrangements of carbon atoms has the greatest entropy?

Accepted Answer

The answer of Each of the following requires 12 carbon...

Question 6

How is your body able to work against the effects of entropy?

Accepted Answer

Eating a balanced diet and proper nourishment provides the body with the necessary nutrients to repair and maintain cells, counteracting the effects of entropy.

Question 7

A(n) chemical reaction releases energy, whereas a(n) reaction requires an input of energy.

Accepted Answer

Exergonic reactions release energy, while endergonic reactions require an input of energy.

Question 8

In an isolated system, all of the following are true of the second law of thermodynamics EXCEPT

Accepted Answer

The second law of thermodynamics states that in an isolated system, the total entropy tends to increase, and energy tends to spread out, becoming less useful. However, not all chemical reactions release more energy than they consume; some reactions require an input of energy.

Question 9

Which of the following is part of the first law of thermodynamics?

Accepted Answer

The first law of thermodynamics states that energy cannot be created or destroyed, only transferred or transformed.

Question 10

Entropy is a measure of an increase in

Accepted Answer

Entropy is a measure of randomness or disorder in a system. As entropy increases, the system becomes more disordered.

Question 11

Similar to a car, a human body is about efficient in converting chemical energy to movement.

Accepted Answer

The human body is about 25% efficient in converting chemical energy from food into mechanical energy for movement, similar to the efficiency of a car engine.

Question 12

What is the ultimate source of energy for almost all forms of life on Earth?

Accepted Answer

Solar energy is the ultimate source of energy for almost all life on Earth, as it drives photosynthesis in plants, which forms the base of most food chains.

Question 13

When solid sodium hydroxide is added to water, the solution gets hot. This is an example of a(n)

Accepted Answer

The process is exergonic because it releases energy in the form of heat when sodium hydroxide dissolves in water.

Question 14

Why is photosynthesis considered an endergonic reaction?

Accepted Answer

Photosynthesis is considered an endergonic reaction because it involves the conversion of low-energy reactants (carbon dioxide and water) into high-energy products (glucose and oxygen), requiring an input of energy from sunlight.

Question 15

How is it possible for living organisms to comply with the second law of thermodynamics?

Accepted Answer

Living organisms comply with the second law of thermodynamics by using energy from the sun to maintain order and perform work, while increasing the overall entropy of the universe.

Question 16

In exergonic chemical reactions,

Accepted Answer

In exergonic reactions, energy is released because the reactants have more energy than the products.

Question 17

All of the following statements are true of the first law of thermodynamics EXCEPT

Accepted Answer

The first law of thermodynamics states that energy cannot be created or destroyed, only transformed. It does not address the efficiency or usefulness of energy conversion, which is related to the second law of thermodynamics.

Question 18

Which of the following does NOT have much potential energy?

Accepted Answer

A ball that has rolled downhill and stopped has minimal potential energy because it is at a low point with no height to convert into energy.

Question 19

In the liver, the polysaccharide glycogen is broken down into glucose monomers. The glucose molecules are then released into the blood when blood sugar levels need to be raised. This process is an example of a(n) reaction.

Accepted Answer

The breakdown of glycogen into glucose is an exergonic reaction because it releases energy as glucose molecules are freed from the glycogen polymer.

Question 20

Which of the following has the greatest amount of kinetic energy?

Accepted Answer

A moving car has the greatest amount of kinetic energy because kinetic energy is directly related to the motion of an object, and a car in motion has significant mass and velocity.

Quiz 6: Energy Flow in the Life of a Cell