Chapter 6 Energy and Metabolism (SB)

Select all of the following that exhibit potential energy only.

-Bow ready to fire an arrow. -A stretched rubber band -A boulder sitting at the top of a hill -Water at the top of a dam

Select two ways to increase the rate of reactions.

-Lower the activation energy -Increase energy of reactants

Select all of the following that can occur during the reduction of an atom or molecule.

-One or more electrons are added to the atom or molecule. -The net charge of the atom or molecule decreases due to addition of negatively charged electron(s).

Living organisms can convert the potential energy stored in chemical bonds into what other forms of energy?

-kinetic energy -potential energy in the bonds of new molecules -light energy -electrical energy (electricity)

An organic molecule has 10 C-H bonds. The full oxidation of all the C-H bonds in this molecule would yield ________________ kcal per mole.

988

In the following chemical reaction, which molecule(s) is(are) reduced? Ae- + B --> A + Be-

B

Which statement about energy conversion is true?

During any type of energy conversion, some of the energy is lost into the environment as heat.

What is the term for the ability to do work?

Energy

________________ stored in the chemical bonds of a molecule can be used to make new bonds in a different molecule.

Energy

True or false: Energy stored in the chemical bonds of a molecule cannot be harvested and used to make new bonds in a different molecule.

False

True or false: When an electron is added to a molecule, the molecule is oxidized.

False

Energy is usually measured as which of the following?

Heat

What are the two main states of energy?

Kinetic energy and potential energy

Which of the following describes the major difference between kinetic and potential energy?

Kinetic energy is the energy of motion and potential energy is associated with the position of an object.

______________________ energy is associated with movement, while _______________________energy is stored energy.

Kinetic, Potential

If you stretch a rubber band, you will give it _________________ energy; and when the rubber band is released, it has __________________ energy when it flies through the air.

Potential, Kinetic

In broad terms, energy can exist in two states: ___________________ energy and ______________________ energy.

Potential, kinetic

The energy that flows through biological systems on Earth ultimately comes from which source?

The Sun

During the breakdown of small organic molecules, oxidation occurs when

electrons are removed from an atom or molecule.

The first law of thermodynamics states that the total amount of _________________ in the universe remains constant.

energy

True or false: When a lion eats a giraffe, it both creates and adds new potential energy to its body.

false

During each energy conversion that happens in a living organism, some of the energy dissipates as ________________.

heat

Heat is a measure of the random motion of molecules, a form of _______ energy.

kinetic

Fats are useful as energy storage molecules because they contain?

many C-H bonds.

Heat is a measure of the random __________________ of molecules.

motion

Redox reaction is a term used to describe an _________________ - ___________________ reaction.

oxidation-reduction

A fraction of the energy from the Sun is captured by plants, algae, and some bacteria through the process of?

photosynthesis

Green plants, certain bacteria, and algae can all perform the process of ____________________during which the energy of light is used to synthesize molecules.

photosynthesis

As living organisms consume other living organisms,

potential energy is transferred from one organism to another.

In chemical reactions, ________________________ refers to the process when one or more electrons are added to a molecule or atom.

reduction

With very few exceptions, all energy that enters biological systems ultimately comes from the _____________________

sun

During photosynthesis, small inorganic molecules are combined into organic molecules using energy from?

sunlight

What is an example of an object with high potential energy?

Water stored in a reservoir behind a dam

What occurs during a redox reaction?

When an atom or molecule is oxidized, the electron that is removed is transferred to another atom or molecule, which is thereby reduced.

In a chemical reaction, an electron is transferred from molecule X to molecule Y. Which of the two molecules is oxidized in this reaction?

X

True or false: Heat energy cannot be used by cells to do work.

true

In photosynthesis, energy absorbed from sunlight is used to?

combine small inorganic molecules into larger organic molecules

The amount of heat required to raise the temperature of one gram of water by one degree Celsius equals which of the following?

One calorie

True or false: The oxidized form of a molecule has less energy than its reduced form.

True

During a chemical reaction, which molecules become oxidized?

Molecules that have an electron removed

During a chemical reaction which molecules become reduced?

Molecules that have one or more electrons added

What is the first law of thermodynamics?

The first law states that energy cannot be created or destroyed.

Which of the following statements about oxidized molecules is true?

They have fewer electrons and less energy than reduced molecules.

True or false: Chemical potential energy stored in the molecules of living organisms can be converted into other forms, such as kinetic energy, light or electricity.

True

True or false: The energy associated with swinging a bat is a type of kinetic energy.

True

The rate of an exergonic reaction can be increased by lowering the ________________________ energy required to destabilize chemical bonds in the reactants.

activation

_______________ energy is the energy required to destabilize existing chemical bonds and initiate a chemical reaction.

activation

In order to be initiated, all chemical reactions, even exergonic ones, need?

activation energy

The _____________ _____________ for an exergonic reaction is lower in the presence of a catalyst for the reaction.

activation energy

Name the type of energy that is a form of potential energy stored in chemical bonds.

chemical

________________ energy is a form of potential energy stored within the covalent bonds of molecules.

chemical

Because cells are too small to maintain significant internal temperature differences, cells rely on ______________________ reactions rather than a ___________________ gradient to do work.

chemical, heat