Unit 3: Cellular Energy & Biochemistry
Standard B-3:
The student will demonstrate an understanding of the flow of energy within and
between living systems.
Standard B-2:
The student will demonstrate an understanding of the structure and function of
cells and their organelles.
This unit is all about ENERGY.
I.
II.
III.
IV.
V.
ATP
Biomolecules
Chemical Reactions
Photosynthesis
Cellular Respiration
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Cellular Energy & Biochemistry
Standard B-3:
The student will demonstrate an understanding of the structure and function
of cells and their organelles.
Indicator B – 3.3:
Recognize the overall structure of adenosine triphosphates (ATP) –
namely, adenine, the sugar ribose, and three phosphate groups –
and summarize its functions (including the ATP-ADP [adenosine
diphosphate] cycle).
Key Concepts:
ATP structure: nitrogenous base (adenine), ribose, phosphate group
ATP – ADP cycle
It is essential for you to know:
 ATP is the most important biological molecule that supplies energy to the cell.
 A molecule of ATP is composed of three parts:
o A nitrogenous base (adenine)
o A sugar (ribose)
o Three phosphate groups bonded together by “high energy” bonds.
 Cells break phosphate bonds as needed to supply energy for most cellular functions,
leaving adenosine diphosphate (ADP) and a phosphate available for reuse.
 The steps in the ATP – ADP cycle
Objectives:
Recognize the overall structure of an ATP molecule.
Summarize the function of ATP.
Illustrate the relationship between ATP and ADP.
Interpret diagrams and equations of the ATP-ADP cycle.
Vocabulary Words:
Define the following vocabulary words in the space provided.
1. ATP
2. ADP
3. Chemosynthesis
4. Heterotroph
5. Autotroph
6. Bond energy
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What do you think about when you hear the word
ENERGY?
List some forms of energy you are familiar with.
Of the list above, which (if any) of the forms of energy can
a living thing use?
Which would you rather have? Explain why.
 50 $1 bills
 1 $50 bill
To live, all organisms must release the energy found in _________ and other compounds.
Autotrophs (also called _____________ )
Plants and some other types of organisms are able to use light energy from the sun to
produce food.
Heterotrophs (also called ___________ )
Organisms that must obtain energy from the foods they consume.
This picture is called a _______ _______.
It shows the flow of _________ through
living things.
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Since energy comes in many different forms, it can easily be __________ for use later. The energy in
our cells is no different. Activities of the cell are powered by ____________ _________. ATP is the
molecule used in most of our cell’s daily functions. So….where does that ATP come from?
Molecules in foods _________ chemical energy in their ___________.
__________________________
_______________________________
Chemical Energy and ATP
ATP
ADP
Where do organisms get ATP from? They break down food molecules (biomolecules) and extract the
ATP found within their bonds. The main biomolecule in which organisms get ATP is from
_______________ like glucose.
*In the next section we will go into more detail about the major biomolecules and their caloric
(energy) values.
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Foods that we eat do not contain ______ directly.
First the food must be __________ then ________ down into smaller molecules that can be
used to make _______. *Think about what happens when you eat cotton candy.
The amount of ATP made from a food source depends on the type of food digested. While
there are 4 main biomolecules, only 3 of them are a source of chemical energy (ATP) for living
things . They are __________________, ________________, and __________________.
Compare their energy values in the chart below.
Carbohydrates
Lipids
Proteins
Cells store small amounts of energy in their cells in the form of ________. This is energy required for
activities < 90 seconds like ____________ ___________. However, when cells require an activity
that lasts longer than 90 seconds, ____________ is broken down in order to release the energy
found in its bonds. Glucose can store _______ times more energy than ATP. If your body uses all the
available glucose, it will then begin to break down lipids. If there are no lipids available for energy use,
this is when your body begins to break down proteins (and muscles). However, if your cells are not in
need of the energy found in glucose, the excess glucose gets turned into _______ and it is stored.
Plants: stored glucose is called __________
*Think about celery.
Animals: stored glucose is called ____________
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calorie vs. Calorie
A calorie (lowercase “c”) is:
A Calorie (uppercase “C”) is:
Which one is found in food?
Each type of food (major biomolecule) holds a different amount
of potential energy.
Proteins have _____ Calories/gram
Carbohydrates have _____ Calories/gram
Lipids have _____ Calories/gram
In many countries outside the US and UK, food energy is measured in ___________ instead of in
Calories.
________ Calorie = _________ Joules = ________ calories
Chemosynthesis
Some organisms don’t use ______ energy to produce chemical
energy.
These organisms may live in a place where ________is not present
or strong enough like hydrothermal vents.
These organisms use a process called _____________ to convert
organic compounds into chemical energy.
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Cellular Energy & Biochemistry
Standard B-3:
The student will demonstrate an understanding of the structure and function
of cells and their organelles.
Indicator B – 3.4:
Summarize how the structure of organic molecules (including
proteins, carbohydrates, and fats) are related to their relative caloric
values.
Indicator B – 3.5:
Summarize the functions of proteins, carbohydrates, and fats in the
human body.
Key Concepts:
Organic molecules (as listed in the indicator)
Protein: amino acid
Fats (lipids): glycerol, fatty acids
Caloric Value
Carbohydrates: monosachharides
It is essential for you to know:
 All organisms are composed of organic molecules which contain carbon atoms.
o Made of smaller units that bond to form larger molecules.
 Energy is stored in the bonds of organic molecules.
o The amount of energy varies with the type of molecule.
 Determines the molecule’s caloric value.
 The three main organic molecules for energy are:
o Carbohydrates
o Lipids
o Proteins
 Nucleic acids (NOT a source of caloric energy) store and transmit genetic information.
Objectives:
Distinguish between organic compounds and inorganic compounds.
Summarize how the structures of organic molecules are related to their relative caloric
values.
Describe the bonding properties of carbon atoms.
Compare the functions of carbohydrates, proteins, fats, and nucleic acids.
.
Vocabulary Words:
Define the following vocabulary words in the space provided.
1. Monomer
2. Polymer
3. Carbohydrate
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4. Protein
5. Lipid
6. Nucleic acid
7. Fatty acid
8. Amino acid
9. Atom
*******************************************************************************************************************
Before you can begin to understand complex molecules such as carbohydrates, lipids, proteins, and
nucleic acids, you must understand how their structure is constructed.
Atoms, Ions, and Molecules (pgs. 36-39)
Why is it important to understand the parts of a living thing in order to understand how it works as a
whole? __________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
An atom is _______________________________________________________________________
Draw and label an atom
What charge does each of the following have? proton _____ neutron _____ electron _____
Where is each of the following found in an atom? proton_____ neutron ______ electron _____
What holds the electrons in place? ____________________________________________________
The # of _______ equals the # of _________, so therefore the overall charge of an atom is neutral.
What is an element? ________________________________________________________________
There are over _____ known elements and about _____ are found in living organisms.
Look at the back of your textbook. Write down a few and say what they are used for.
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How are elements represented? ______________________________________________________
How are they arranged so that people can easily see them? ________________________________
How is Aluminum written? _____ Calcium? _____ Argon? _____ Helium? _____ Hydrogen _____
The atomic number refers to? ____________________ The mass number? ____________________
Are most elements found alone or combined with other elements? ____________________________
What does a chemical formula show? __________________________________________________
What are three examples of chemical formulas?
1.
2.
3.
The ____________ and ______________ properties of a chemical compound can be very different.
How is H2O an example of this? _______________________________________________________
________________________________________________________________________________
What is a chemical bond? ___________________________________________________________
What are the two types of bonds? ________________ and _____________________
Fill out the table with facts about each. Be sure to give an example of each type.
Ionic Bonds
Covalent Bonds
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Carbon-Based Molecules (pgs. 44-48)
Carbon atoms have unique bonding properties.

The element referred to as the building block of life is _____________.

_______________ is the basis of most molecules that make up living things.

In its outer energy level, C atoms have ________ valence electrons.

C can form _________ bonds with ___________________
_______________________________________________.

C compounds can form ______ fundamental structures. They are ________________, _______________,
or ___________________. Sketch each one below.
Four main types of carbon-based molecules are found in living things.

The four main types of carbon-based molecules found in living things are _______________,
_______________, _________________, and _________ ___________.
Carbohydrates (pg. 45)

A carbohydrate is __________________________________
_____________________________________________________________________________________
__________.

Carbohydrates are known as ______________ and ___________________.

Foods high in carbohydrates would include _____________
_______________________________________________.

Living things need carbohydrates for use as ___________.
Lipids (pg. 46)

Lipids are ___________. They include _________________
________________________________________________.

Foods high in lipids would include _____________________
________________________________________________.

What is the difference between saturated and unsaturated fats?
____________________________________________
_____________________________________________________________________________________
__________________________________________________________.

We often hear that cholesterol is not good for you, however living things need cholesterol for
_______________________________________________________________________________
____________________________________________________________________________
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Proteins (pg. 47)

Proteins are ______________________________________
_______________________________________________.
o Polymers are ________________________________
__________________________________________.
o The monomers of a protein ________ _________.

If the wrong amino acid is in place, _________________ will result.

Foods high in protein would include ___________________
______________________________________________________________________________
_________________.

One important type of protein found in our bodies are _________, which speed up chemical
reactions.
*We will discuss these in greater detail next.
Nucleic Acids (pg. 48)

Nucleic acids are __________________________________
________________________________________________.

The function of nucleic acids is _______________________
________________________________________________.

There are two types of nucleic acids. They are ___________ and _______________.
Look at each picture and decide which carbon-based molecule it is. Write that molecule’s name on
the line.
______________
_______________
______________
________________________
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Fill in the following chart about Carbon-Based Molecules
Molecule
Contains the
Elements
Function in
Living Things
Examples
Include
Carbohydrates
Lipids
Proteins
Nucleic Acids
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Cellular Energy & Biochemistry
Standard B-2:
The student will demonstrate an understanding of the structure and function
of cells and their organelles.
Indicator B – 2.8: Explain the factors that affect the rates of biochemical reactions
(including pH, temperature, and the role of enzymes as catalysts).
Key Concepts:
Biochemical reactions: activation energy
pH: buffers
Catalyst: enzyme
It is essential for you to know:
 Biochemical reactions allow organisms to grow, develop, reproduce, and adapt.
o Breaks down some substances and builds others up.
 The amount of energy required for a chemical reaction to occur is called activation energy.
o Sometimes energy is absorbed during the reaction
o Sometimes energy is released during the reaction
 Several factors affect the rate of chemical reactions.
o Temperature
o pH
o Enzymes
Objectives:
Describe how bonds break and reform during chemical reactions.
Explain why chemical reactions release or absorb energy.
Explain the effect of a catalyst on activation energy.
Describe how enzyme regulate chemical reactions.
State that factors such as temperature and pH affect the rates of chemical reactions.
Vocabulary Words:
Define the following vocabulary words in the space provided.
1. Chemical reaction
2. Reactant
3. Product
4. Bond energy
5. Equilibrium
6. Activation energy
7. Exothermic
8. Endothermic
9. Catalyst
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10. Enzyme
11. Substrate
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Chemical Reactions
What is a chemical reaction?
In the space below, write a definition for each of the terms.
Definition
Reactants
Products
What is released or absorbed whenever chemical bonds form or are broken?
The energy needed to start a chemical reaction is called ______________ _____________.
In the graph
to the right,
label the
following:
Energy-Absorbing Reaction
--------------------------------------------------------
Reactants
-------------------------------------------------------Products
Endothermic
or
Exothermic
Energy
Course of
Reaction
--------------------------------------------------------
Activation
Energy
Energy-Releasing Reaction
Using the above
graph, fill in the
graph to the right.
Endothermic
or
Exothermic
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Effects on Chemical Reactions
The following can affect the rate of a chemical reaction. Discuss each.
Temperature:
pH:
Enzymes:
Enzymes
What is a catalyst?
Proteins that act as a biological catalysts are called ______________. They are very SPECIFIC.
What do they do?
The reactants of enzyme-catalyzed reactions are known as _______________.
The binding together of an enzyme and a substrate forms a(n) ________________.
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