Exam 3 Review Sheet (Ch. 8, 9 and 10)
Please note: To receive extra credit on Exam 3, this ENTIRE review sheet must be
completed. As you can see, there are several questions for each number below. Writing
your answers on this sheet is not enough effort to receive extra credit!!! (It also will not
help you learn the material for the exam!)
Ch 8: An Introduction to Metabolism
1. What is the difference between an anabolic and a catabolic reaction? Which is
exergonic? Endergonic? Give examples of each.
Anabolic Reaction: Building reaction (Amino Acid– Protein) (Endergonic)
Catabolic Reaction: Breaking down reaction (Protein– Amino Acid) (Exergonic)
Exergonic Reaction: Giving off energy
Endergonic Reaction: Taking in energy
1. What is a metabolic pathway? What is required at each step of a metabolic
pathway? How can it be regulated?
Metabolic pathway is a chain of reactions that are each catalyzed by an enzyme.
It can be regulated by… Inhibit Enzymes
1. What is energy? What form of energy is utilized in the cell? What is energy used
for in the cell?
ATP is used in the cell
Electrons are also used as energy in the cell
Used to keep cell alive and do specific functions
1. State the first and second laws of thermodynamics. How does each pertain to
energy flow on earth? How does it pertain to metabolism? What is entropy? Be
able to give examples of both laws or recognize examples of both laws.
1st Law Energy can be transferred not created or destroyed
2nd Law eventually everything becomes more disordered in a system
Entropy is randomness. (constant flow of energy increases entropy)
chaos=high entropy organized=low entropy
, 1. What is free energy? Know the equation for Gibb’s free energy (∆G = GProducts –
GReactants). How does ∆G relate to an endergonic reaction? An Exergonic reaction?
In terms of energy, is a living organism ever at equilibrium?
Free energy is the energy that can be used to do work. Living organisms can’t ever
be at equilibrium.
2. What is the structure of ATP? Why is ATP so important to living cells? What
reaction occurs when ATP gives off energy? What reaction occurs when ATP is
created? Is each endergonic or exergonic? HOW does ATP transfer energy to
another molecule? How is ATP generated in the cell?
Adenosine Triphosphate (3 phosphate groups)
ATP is important to living cells because it provides the energy needed for them to
survive.
ATP goes to ADP + a phosphate when it gives off energy (energy is stored in bonds)
Cellular respiration and photosynthesis create ATP
Photosynthesis is an endergonic reaction
Cellular Respiration is an exergonic reaction
1. Enzymes are catalysts. What does that mean? What is the function of an enzyme?
What is a substrate?
- They help to speed up chemical reactions and are not consumed by reaction
- Enzymes bind to substrates and perform chemical reactions
- Substrates are what bind to the enzyme
1. What is the activation energy of a reaction? How do enzymes affect the activation
energy of a reaction? How does this speed up chemical reactions? Know the
characteristics of enzymes and sites on the enzyme (active site, allosteric site).
- Activation energy is the energy needed to start a chemical reaction
- Enzymes lower the activation energy
- Enzymes speed up chemical reactions because there is less energy needed to make
the reactants into the products
- Active site is place substrate binds to
- Allosteric site is place other than active site where a molecule can bind to change
enzyme
1. How do pH, temperature, substrate concentration, and enzyme concentration affect
enzyme activity? Be able to recognize and/or draw the graphs from lecture!
Please note: To receive extra credit on Exam 3, this ENTIRE review sheet must be
completed. As you can see, there are several questions for each number below. Writing
your answers on this sheet is not enough effort to receive extra credit!!! (It also will not
help you learn the material for the exam!)
Ch 8: An Introduction to Metabolism
1. What is the difference between an anabolic and a catabolic reaction? Which is
exergonic? Endergonic? Give examples of each.
Anabolic Reaction: Building reaction (Amino Acid– Protein) (Endergonic)
Catabolic Reaction: Breaking down reaction (Protein– Amino Acid) (Exergonic)
Exergonic Reaction: Giving off energy
Endergonic Reaction: Taking in energy
1. What is a metabolic pathway? What is required at each step of a metabolic
pathway? How can it be regulated?
Metabolic pathway is a chain of reactions that are each catalyzed by an enzyme.
It can be regulated by… Inhibit Enzymes
1. What is energy? What form of energy is utilized in the cell? What is energy used
for in the cell?
ATP is used in the cell
Electrons are also used as energy in the cell
Used to keep cell alive and do specific functions
1. State the first and second laws of thermodynamics. How does each pertain to
energy flow on earth? How does it pertain to metabolism? What is entropy? Be
able to give examples of both laws or recognize examples of both laws.
1st Law Energy can be transferred not created or destroyed
2nd Law eventually everything becomes more disordered in a system
Entropy is randomness. (constant flow of energy increases entropy)
chaos=high entropy organized=low entropy
, 1. What is free energy? Know the equation for Gibb’s free energy (∆G = GProducts –
GReactants). How does ∆G relate to an endergonic reaction? An Exergonic reaction?
In terms of energy, is a living organism ever at equilibrium?
Free energy is the energy that can be used to do work. Living organisms can’t ever
be at equilibrium.
2. What is the structure of ATP? Why is ATP so important to living cells? What
reaction occurs when ATP gives off energy? What reaction occurs when ATP is
created? Is each endergonic or exergonic? HOW does ATP transfer energy to
another molecule? How is ATP generated in the cell?
Adenosine Triphosphate (3 phosphate groups)
ATP is important to living cells because it provides the energy needed for them to
survive.
ATP goes to ADP + a phosphate when it gives off energy (energy is stored in bonds)
Cellular respiration and photosynthesis create ATP
Photosynthesis is an endergonic reaction
Cellular Respiration is an exergonic reaction
1. Enzymes are catalysts. What does that mean? What is the function of an enzyme?
What is a substrate?
- They help to speed up chemical reactions and are not consumed by reaction
- Enzymes bind to substrates and perform chemical reactions
- Substrates are what bind to the enzyme
1. What is the activation energy of a reaction? How do enzymes affect the activation
energy of a reaction? How does this speed up chemical reactions? Know the
characteristics of enzymes and sites on the enzyme (active site, allosteric site).
- Activation energy is the energy needed to start a chemical reaction
- Enzymes lower the activation energy
- Enzymes speed up chemical reactions because there is less energy needed to make
the reactants into the products
- Active site is place substrate binds to
- Allosteric site is place other than active site where a molecule can bind to change
enzyme
1. How do pH, temperature, substrate concentration, and enzyme concentration affect
enzyme activity? Be able to recognize and/or draw the graphs from lecture!
