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SECTION 2-1, COMPOSITION OF MATTER
The structure and function of all living things are governed by the laws of
Chemistry (The Central Science). An understanding of the fundamental
principles of chemistry will give you a better understanding of living things and
how they function.
OBJECTIVES:
1. Define the term matter.
2. Explain the relationship between elements and atoms.
3. Draw and label a model of the structure of an atom.
4. Contrast covalent and ionic bonds.
MATTER
MATTER - EVERYTHING IN THE UNIVERSE IS MADE OF MATTER.
Matter is defined as Anything that has Mass and takes up Space.
ELEMENTS AND ATOMS
ELEMENTS ARE PURE SUBSTANCES THAT CANNOT BE BROKEN DOWN
CHEMICALLY INTO SIMPLER KINDS OF MATTER.
2. More than 100 elements have been identified, though Fewer than 30 are
Important in Living Things. (The Periodic Table of Elements)
3. All of the Elements are arranged on a Chart known as THE PERIODIC
TABLE. Among the information provided in The Periodic Table are the ATOMIC
NUMBER, THE CHEMICAL SYMBOL, AND THE ATOMIC MASS FOR EACH
ELEMENT.
4. More than 90 Percent of the Mass of living things is composed of JUST FOUR
ELEMENTS: OXYGEN, O, CARBON, C, HYDROGEN, H, AND NITROGEN, N.
5. Each Element has different Chemical Symbol which consist of One or Two
Letters.
6. In most cases, the Symbol Derives from the First Letter or Other Letters in the
Name of the Element, like - C for Carbon or Cl for Chlorine.
7. Some of the Symbol Names come form their Latin Name - Na for Sodium
(natrium) or K for Potassium (Kalium).
ATOMS
1. The Simplest Particle of an Element that RETAINS ALL of the PROPERTIES
of the Element is an ATOM. Atoms are so small that their TRUE Structure
Cannot be Observe, but scientist have developed Models that describe the
Structure and Properties of the Atom (Figure 2-2).
2. An Atom consists of THREE Kinds of Particles, PROTONS AND NEUTRONS
FOUND IN THE ATOMS NUCLEUS, AND ELECTRONS.
3. The Central Core of an Atom is called the NUCLEUS, Most of the MASS of an
Atom is concentrated in its Nucleus and consists of Two Kinds of Particles:
A. PROTONS: A POSITIVE CHARGED PARTICLE. All Atoms of a given
Element have the SAME Number of Protons. The Number of Protons in an Atom
is called the ATOMIC NUMBER which appears Above the Chemical Symbol.
B. NEUTRONS - NEUTRONS HAVE NO ELECTRICAL CHARGE. The
number of Neutrons in an Atom is derived by the ATOMIC MASS MINUS THE
ATOMIC NUMBER. OR THE NUMBER OF PROTONS PLUS THE NUMBER
OF NEUTRONS EQUAL THE ATOMIC MASS.
4. The number of Positively Charged Protons is Balanced by an Equal Number of
small, NEGATIVELY CHARGED PARTICLES called ELECTRONS (e-).
5. The Electrical Charges of the Electrons OFFSET those of the Protons, making
the NET Electrical Charge of an Atom ZERO.
6. Electrons are high-energy particles with very little mass. They MOVE About
the Nucleus at very High Speeds in one of seven different ORBITALS OR
ENERGY LEVELS. An orbitals is a three-dimentional region around a nucleus
that indicates the probable location of an electron. (fig. 2-2)
7. Electrons in orbitals that are farther away form the nucleus have Greater
Energy than electrons that are in orbitals closer to the nucleus.
8. Each Orbital or Energy Level (shell) can hold only a certain number of
electrons. The First Level, Nearest the Nucleus, can only hold TWO Electrons.
The Second and other OUTER Levels can hold up to EIGHT Electrons each.
9. A STABLE ATOM IS AN ATOM THAT HAS A FULL OUTER LEVEL.
10. All atoms of an element have the same number of protons. However, all
atoms of an element do not neceassarily have the same number of neutrons.
11. Atoms of the same element that have different number of Neutrons are called
ISOTOPES. Additonal neutrons change the mass of an element.
COMPOUNDS
1. Under Natural Conditions, MOST Elements DO NOT Exist by themselves;
Most elements COMBINE with other Elements.
2. A PURE SUBSTANCE that is made up of Atoms of TWO or MORE Elements
is called a COMPOUND.
3. The Proportion of each kind of Atom is FIXED, A CHEMICAL FORMULA
Shows the KIND and PROPORTION of Atoms each Element that forms a
particular Compound - WATER = H20 - indicates TWO HYDROGEN Atoms to
ONE OXYGEN Atom.
4. The Physical and Chemical Properties of a Compound DIFFER form the
Physical and Chemical Properties of the individual Elements that compose it.
Both H and O are found as gases, but the combine to form Water a Liquid.
5. The Tendency of elements to combine and form Compounds depends on the
Number and Arrangement of Electrons in their Atoms.
6. An Atom is Chemically Stable when its Outermost Energy Level is Filled (8 E-)
7. Most Atoms are NOT Stable in their Natural State, so they tend to React, or
Combine with other Atoms (CHEMICAL REACTIONS), in ways that make the
Atoms More Stable.
8. Most Atoms tend to undergo CHEMICAL REACTIONS, Combining in ways
that Cause their Atoms to Become Stable. In Chemical Reactions, CHEMICAL
BONDS are broken, Atoms are Rearranged, and New Chemical Bonds, or
Attachments, are formed.
COVALENT BONDS - SHARING OF ELECTRONS
1. A COVALENT BOND forms when TWO Atoms SHARE One or MORE Pairs of
Electrons. (Figure 2-4)
2. Water is made up by Atoms Held together by a Covalent Bonds. In the
Presence of one another, hydrogen atoms and oxygen atoms can achieve
stability by sharing pairs of electrons in a ration of TWO Atoms of Hydrogen to
ONE Atom of Oxygen.
3. Covalent Bonding Results in the Formation of MOLECULES.
4. A MOLECULE is the Simplest Part of a Substance that Retains all the
Properties of the Substance and that can Exist in a Free State.
5. Water formation is an example of a Molecule of Water.
IONIC BONDING - TRANSFER OF ELECTRONS
1. IONIC BOND IS A BOND FORMED BY ELECTRICAL ATTRACTION
BETWEEN TWO OPPOSITLY CHARGED IONS.
2. AN ATOM OR MOLECULE WITH AN ELECTRICAL CHARGE IS CALLED AN
ION.
3. If an Atom has More Protons than Electrons it is POSITIVELY CHARGED (+).
4. If an Atom has More Electrons than Protons it is NEGATIVELY CHARGED (-)
The formation of Table Salt (NaCl) is an example of an IONIC BOND:
A. A Sodium Atom (Na) has ONE outer electron.
B. A Chlorine Atom (Cl) has SEVEN outer electrons.
C. To become stable, the One outer E- of a Na atom is transferred to a Cl
atom. Na+
D. To become more stable, Cl gains the E- from Na Atom. Cl-.
E. Because Positive and Negative Electrical Charges attract each other, the
Na+ and Cl- attract each other. This Attraction is called an IONIC BOND.
F. The resulting Compound, Sodium Chloride, NaCl, is an Ionic Compound
and is familiar to you as Common Table Salt.
SECTION 2-2, ENERGY
One important characteristic of all living things is that they Use Energy. The
amount of Energy in the Universe remains the same over time, but Energy can
change in form constantly. It is the flow of energy- from the sun to and through
almost every organism on Earth- that biologist seek to understand when they
study the chemistry of living things.
OBJECTIVES:
1. Describe the physical properties of each state of matter.
2. Describe the role of reactants and products in chemical reactions.
3. Explain the relationship between enzymes and activation energy.
4. Explain how oxidation and reduction reactions ar linked.
ENERGY AND MATTER
1. Scientist define ENERGY as the ability to do work or cause change.
2. Energy can occur in various forms, and one form of energy can be converted
to another form.
3. Some forms of energy important to living things include CHEMICAL ENERGY,
THERMAL ENERGY, ELECTRICAL ENERGY, AND MECHANICAL ENERGY.
4. Biologist often refer to FREE ENERGY, the Energy in a system that is
available for work. For example, in a Cell, it is the Energy that is available to
Fuel Cell Processes.
5. As Energy Flows through an organism, it may be converted from one form to
another- the Food you eat is changed by your body from the Chemical Energy
found in Food into Thermal and Mechanical Energy, to be used by your body.
ENERGY AND CHEMICAL REACTIONS
1. Living Things undergo many thousand of Chemical Reactions as part of their
life process.
2. CO2 + H20
H2CO3 is a sample Chemical Reaction. (Figure 2-7)
Carbon Dioxide and Water can Combine to form Carbonic Acid.
3. The REACTANTS are on the LEFT Side of the Equation. The PRODUCTS
are on the RIGHT side of the Equation.
4. In a Chemical Reaction, Bonds present in the Reactants are Broken. The
Elements are Rearranged, and NEW Compounds are formed as the Products.
5. Much of the Energy your body need is provided by Sugars from Food.
6. You body undergoes a series of Chemical Reactions in which Sugars are
broken down to Carbon Dioxide and Water. In this process, energy is released
for use by the body. (Breaking Chemical Bonds Releases Energy)
7. Chemical Reaction that involve a Net Release of Free Energy are called
EXERGONIC REACTIONS.
8. Reactions that involve a Net Absorption of Free energy are called
ENDERGONIC REACTIONS.
9. For most Chemical Reactions to begin, Energy Must Be Added to the
Reactants.
10. In many Chemical Reactions, the AMOUNT of Energy NEEDED to START
the Reaction, called ACTIVATION ENERGY, IS HIGH. (Figure 2-8)
11. Certain Chemical Substances, known as CATALYSTS, Reduce the amount
of Activation energy Needed. A Reaction in the presence of a Catalyst will
proceed Spontaneously or with the addition of a small amount of Energy.
12. ENZYMES are an important class of Catalysts in living things. A single
organism may have thousands of different Enzymes.
OXIDATION-REDUCTION REACTIONS
1. Many of the Chemical Reactions that help Transfer Energy in living things
involve the TRANSFER OF ELECTRONS.
2. These Reactions in which E- are Transferred Between Atoms are known as
OXIDATION- REDUCTION REACTIONS, OR REDOX REACTIONS. The
Formation of Table Salt (Figure 2-5)
3. In an OXIDATION REACTION, a Reactant LOSES One or More E-, becoming
more POSITIVE IN CHARGE. The Sodium Atom undergoes Oxidation to form
Na+ ion.
4. In a REDUCTION REACTION, a Reactant GAINS One or more E-, Becoming
more NEGATIVE IN CHARGE. The Chlorine Atom undergoes Reduction to form
Cl- ion.
5. REDOX REACTIONS ALWAYS OCCUR TOGETHER. An Oxidation Reaction
occurs, and the E- given up by one substance is then accepted by another
substance in a Reduction Reaction.
SECTION 2-3, WATER AND SOLUTIONS
Compare the body of the jellyfish with your own body. The jellyfish will die if it is
removed for its water environment. You can live in the driest parts of Earth.
Jellyfish and humans seem utterly unlike each other, yet the bodies of both are
made of cells filled with water. The chemical reactions of all living things take
place in an Aqueous environment. Water has several properties that make it one
of the most important compounds found in living things.
The chemistry of living things involves the study of solutions. A large portion of
the Mass of living things is Water, and the Chemical Reactions of life occur for
the most part in water. The electricity that courses through your nerves is
transmitted through watery pathways of dissolved ions. Chemical messengers
(Hormones) that regulate your body's metabolism move through the watery
medium of you blood.
OBJECTIVES:
1. Describe the structure of a water molecule.
2. Explain how water's polar nature affects its ability to dissolve substances.
3. Outline the relationship between hydrogen bonding and the different properties
of water.
4. Identify the roles of solutes and solvents in solutions.
5. Difderentiate between acids and bases.
POLARITY
1. Many of Water's Biological Functions stem from its Chemical Structure.
2. In the Water Molecule, H2O, the Hydrogen and Oxygen Atoms SHARE
Electrons to form a Covalent Bond, but these atoms DO NOT Share the
electrons Equally.
3. The Oxygen Atom, because of it 8 Protons versus Hydrogen's 1 Proton,
PULLS the Shared Electrons towards its Nucleus and AWAY from the Hydrogen
Atom. As a result, the Electrical Charge is UNEVENLY Distributed in the Water
molecule. (Fig. 2-8)
4. Although the TOTAL Electrical Charge on a Water Molecule is NEUTRAL, the
region of the molecule where the Oxygen Atom is located has a Slightly
NEGATIVE Charge, while the regions of the molecule where each of the Two
Hydrogen Atoms are located have a Slightly POSITIVE Charge.
5. Because of this UNEVEN PATTERN of CHARGE, Water is called a POLAR
MOLECULE. Molecules with a Slightly
Negative End and a Slightly Positive are called Polar Molecules.
6. It is this Polar Nature that makes Water VERY EFFECTIVE in Dissolving many
other substances.
7. Water Dissolves Other Polar Substances including, Sugars, some Proteins,
and Ionic Compounds such as Sodium Chloride, NaCl.
8. An Ionic Compound mixed in water trends to DISSOCIATE (Break Apart) into
Ions. This breaking up of an Ionic Compound FREES Ions to participate in many
Biological Reactions. (Figure 2-9)
HYDROGEN BONDING
1. The Polar Nature of Water also causes Water Molecules to be attracted to one
another or stick together.
2. The Type of ATTRACTION that Holds TWO Water Molecules Together is
called HYDROGEN BONDING. (Figure 2-10)
3. A POSITIVE REGION OF ONE MOLECULE IS ATRACTED TO THE
NEGATIVE REGION OF ANOTHER MOLECULE.
4. A Hydrogen Bond is a WEAK Bond that can be easily broken.
5. The Hydrogen Bonds in Water exert a significant Attractive Force, causing
Water to Cling to Itself (Cohesion) and to other Surfaces (Adhesion).
6. An Attractive Force BETWEEN PARTICLES OF THE SAME KIND is known as
COHESION. This causes Water to look like it is Climbing up the side of a Glass.
7. ADHESION is the Attractive Force BETWEEN UNLIKE SUBSTANCES.
8. Together, Adhesion and Cohesion enable Water Molecules to MOVE
UPWARD through narrow tubes Against the PULL OF GRAVITY. This Property
of Water is known as CAPILLARITY. This is what allows Plants to move Water
from their Roots to their Leaves. (fig. 2-11)
9. Water MUST GAIN or LOSE a LARGE Amount of ENERGY for its
Temperature to Change. This makes Water a VERY
STABLE Molecule.
10. Water's ability to Absorb Large amounts of Energy HELPS keep cells at an
EVEN Temperature despite Temperature changes in the Environment.
SOLUTIONS
1. A SOLUTION is a Mixture in which One or More Substances are
UNIFORMLY Distributed in Another Substance. Solutions can be mixtures of
liquids, solids, or gases.
2. Think of Sugar Water (The Solution) - the Sugar is dissolved in the Water and
is Uniformly Distributed.
A. The SOLUTE (Sugar) is the Substance Dissolved in the Solution (Sugar
Water). The particles that compose the Solute may be Ions, Atoms, or
Molecules.
B. The SOLVENT (Water) is the Substance in which the Solute is dissolved.
C. When Sugar, a Solute, and Water, a Solvent, are mixed, a Solution of
Sugar Water Results.
D. Though the Sugar Dissolves in the Water, Neither of the molecules are
Altered Chemically. If the Water is boiled away, the Sugar Molecules remain and
are Unchanged.
3. Solutions can be composed of various proportions of a given Solute in a given
Solvent. 1 cup of Sugar to 3 cups of water.
ACIDS AND BASES
1. One of the most important aspects of living systems is the degree of its acidity
or alkalinity (Base).
2. In water, the force of attraction between molecules is so strong that the oxygen
atom of one molecule can actually remove the hydrogen from other water
molecules.
3. This breaking apart of the water molecule into TWO Ions of opposite charge is
called DISSOCIATION OF WATER.
H20
H+ + OH-
4. One molecule of water dissociates to form TWO Ions, H+ and OH-. The OHis known as the HYDROXIDE ION. The free H+ ion can react with another water
molecule:
H+ + H2O
H3O+
5. The H3O+ ion is known as the HYDRONIUM ION.
6. ACIDITY or ALKALINITY is a measure of the relative amounts of Hydronium
Ions and Hydroxide Ions dissolved in a Solution.
A. NEUTRAL SOLUTION - If the number of Hydronium Ions in a solution
EQUALS the number of Hydroxide Ions, the Solution is said to be Neutral.
B. ACID - If the number of Hydronium Ions (H3O+) in a Solution is GREATER
than the number of Hydoxide Ions (OH-), the Solution is an ACID. Acids tend to
have a SOUR Taste and in concentrated forms are Highly Corrosive.
HCL
H+ + Cl-
C. BASE - If a Solution contains MORE Hydroxide Ions (OH-) than Hydronium
Ions (H3O+) it is defined as a BASE. Bases tend to FEEL Slippery (soap) and
have a BITTER Taste.
NaOH
Na+ + OH-
pH
1. Scientist have developed a Scale for comparing the relative concentration of
Hydronium Ions to Hydroxide Ions in Solution called the pH SCALE. (Figure 214)
2. The pH Scale ranges from 0 to 14.
3. A Solution with a pH of 0 is VERY ACIDIC.
4. A Solution with a pH of 7 is NEUTRAL.
5. A Solution with a pH of 14 is VERY BASIC.
6. The pH of an solution can be measured with Litmus Paper or with some other
chemical indicators that changes color at various pH Levels.
BUFFERS
1. The control of pH is important for Living Things.
2. Enzymes can function only within a very narrow pH range.
3. The control of pH in organisms is often accomplished with BUFFERS.
4. BUFFERS are Chemical Substances that NEUTRALIZE Small amounts of
either Acid or a Base added to a solution.
5. Some of your body's fluids, such as Stomach Acid and Urine, are Acidic.
Others, such as Intestinal Fluid and Blood are Basic.
6. Complex Buffering Systems maintain the pH Values of your body's many fluids
at Normal or Safe
CARBON COMPOUNDS
Although water is the primary medium for life on Earth, most of the molecules
from which living organisms are made are based on the element carbon (C).
Carbon's ability to form large and complex molecules has contributed to the great
diversity of life.
OBJECTIVES:
1. Distinguish between organic and inorganic compounds.
2. Explain the importance of carbon bonding in biological molecules.
3. Identify functional groups in biological molecules.
4. Summarize how large carbon molecules are synthesized and broken down.
5. Describe how the breaking down of ATP supplies energy to drive chemical
reactions.
CARBON BONDING
1. All of the many compounds discovered can be classified in TWO Broad
Categories: ORGANIC COMPOUNDS AND INORGANIC COMPOUNDS.
A. ORGANIC COMPOUNDS contain CARBON ATOMS that are Covalently
Bonded to other Carbon Atoms and to other Elements as well - typically
Hydrogen, Oxygen, and Nitrogen.
B. INORGANIC COMPOUNDS, with a few exception, do not contain carbon.
2. A Carbon Atom has FOUR Electrons in its outermost Energy Level, to be
stable a Carbon Atom needs EIGHT Electrons in its outermost level, a Carbon
Atom therefore READILY forms FOUR COVALENT BONDS with other Elements.
3. Carbon also READILY bonds with other Carbon Atoms, forming Straight
Chains, Branched Chains, or Rings. (Figure 3-1)
4. This tendency of Carbon to Bond with itself results in an enormous Variety of
ORGANIC COMPOUNDS.
5. Carbon can Share Two or even Three Pair of Electrons with another Atom
(Figure 3-2)
A. SINGLE BOND - A bond formed when two atoms share ONE pair of
electrons.
B. DOUBLE BOND - Atoms share TWO pairs of electrons.
C. TRIPLE BOND - Atoms Sharing THREE pairs of electrons.
FUNCTIONAL GROUPS
1. In MOST Organic Compounds, Cluster of Atoms, called FUNCTIONAL
GROUPS, Influence the Properties of the molecule they Compose. (Table 3-1)
2. The FUNCTIONAL GROUP IS THE STRUCTURAL BUILDING BLOCK THAT
DETERMINES THE CHARACTERISTICS OF THE COMPOUND.
3. One Functional Group important to living things is the HYDROXYL GROUP,
represented by --OH. (Table 3-1)
4. An ALCOHOL is an Organic Compound with a Hydroxyl Group attached to
one of its Carbon Atoms.
5. The Hydroxyl Group makes Alcohol a Polar molecule that has Some
Properties similar to Water, including the Ability to Form Hydrogen Bonds.
6. Other functional groups important to living things are shown in Table 3-1.
LARGE CARBON MOLECULES
1. Large Carbon Compounds are built up from Smaller Simpler Molecules called
MONOMERS (MONO = ONE).
2. Monomers can Bind to one another to form Complex Molecules known as
POLYMERS. (POLY = MANY).
3. A Polymer consist of repeated, linked units, forming Large Polymers called
MACROMOLECULES. (MACRO = LARGE)
4. Monomers link to form Polymers through a Chemical Reaction called
CONDENSATION REACTION. During the formation of Polymers, Water, H2O, is
Released or is By Product of the Reaction.
5. Example (Figure 3-8) During the Formation of the Sugar SUCROSE, which is
Table Sugar, GLUCOSE and FRUCTOSE Combine.
6. In the Chemical Reaction the Glucose Molecule Releases a Hydroxide Ion,
OH-, and the Fructose Molecule Releases a Hydrogen Ion, H+. The OH- and H+
Ions that are Released Combine to Produce a Water Molecule =
CONDENSATION REACTION.
7. The BREAKDOWN of some Complex Molecules, such as Polymers, occurs
through a process known as HYDROLYSIS.
8. Hydrolysis is the Reversal of a Condensation Reaction. The ADDITION of
Water, to some Polymers can Break the Bonds that hold them together.
Four main classes of Organic Compounds are essential to the life processes of
All Living Things: CARBOHYDRATES, LIPIDS (FAT), PROTEINS, and
NUCLEIC ACIDS (DNA, RNA). These Compound are built from Carbon,
Hydrogen, and Oxygen, the Atoms occur in different Ratios in each class of
Compound. Despite their similarities, the different classes of compounds have
different properties.
OBJECTIVES:
1. Distinguish between monosaccharides, disaccharides, and polysaccharides.
2. Describe the relationship between amino acids and protein structure.
3. Describe the induce fit model of enzyme action.
4. Compare the structure and function of each of the different types of lipids.
5. Compare the nucleic acids DNA and RNA.
CARBOHYDRATES
1. The cells of the human body obtain MOST of their ENERGY from
CARBOHYDRATES.
2. CARBOHYDRATES ARE COMPOUNDS MADE OF CARBON, HYDROGEN,
AND OXYGEN IN A RATIO OF ABOUT TWO HYDROGENS TO ONE OXYGEN
ATOM. THE NUMBER OF CARBON ATOMS VARIES.
3. Sugars, Starches and Cellulose are Carbohydrates.
4. There are THREE TYPES of Carbohydrates, grouped according to complexity:
MONOSACCHARIDES, DISACCHARIDES, AND POLYSACCHARIDES.
5. MONOSACCHARIDES ARE SINGLE SUGARS (Simple Sugar) SUCH AS
GLUCOSE, GALACTOSE, A SUGAR FOUND IN MILK, AND FRUCTOSE, A
SUGAR FOUND IN FRUITS. (C6 H12 O6).
6. Glucose, Fructose, and Galactose have the same Molecular Formula, C 6 H12
O6, but their Differing Structures determine the different Properties. Compounds
like these sugars, with a Single Chemical Formula but Different Forms, are called
ISOMERS. (Figure 3-4)
7. DISACCHARIDES, OR DOUBLE SUGARS, CONSIST OF TWO SINGLE
SUGARS (Monosaccharides) LINKED TOGETHER. Common disaccharides
include SUCROSE, OR TABLE SUGAR; LACTOSE, OR MILK SUGAR; AND
MALTOSE; A SUGAR CONTAINED IN CEREAL GRAINS.
8. POLYSACCHARIDE IS A CARBOHYDRATE MADE OF LONG CHAINS OF
SUGARS ("Many Sugars", Three or More Monosaccharides). The prefix POLY
means "Many". Starches, such as those in BREAD, PASTA, AND POTATOES,
ARE POLYSACCHARIDES.
9. Animals store Glucose in the form of Polysaccharide Glycogen in the Liver and
Muscles to be used as Quick Energy. Glycogen consist of hundreds of Glucose
Molecules strung together in a highly branched chain.
10. Plants convert excess sugars into Starches for long-term storage. Cellulose
is a Polysaccharide contained in the cell walls of plants. Cellulose gives Strength
and Rigidity to plant cells and makes up about 50 percent of wood.
PROTEINS
1. Proteins are Organic Compounds Composed mainly of Carbon, Hydrogen,
and Nitrogen.
2. PROTEINS ARE THE CONSTRUCTION MATERIALS FOR THE BODY
PARTS SUCH AS MUSCLES, SKIN, AND BLOOD.
3. Our cells need proteins to make other proteins, such as enzymes.
4. Proteins are made up of smaller units called AMINO ACIDS. The Monomer
Building Blocks of Protein.
5. Our bodies contain thousands of different proteins. All these proteins are
made from about 20 Different Amino Acids.
6. Amino Acids Differ ONLY in the type of R Group they Carry. The difference
among the Amino Acid R Groups gives different Proteins Very Different Shapes.
(Figure 3-7)
7. The Different shapes allow Proteins to perform many different roles in the
Chemistry of Living Things.
8. Two Amino Acids bond to form a DIPEPTIDE, during a Condensation
Reaction, Two Amino Acids form a Covalent Bond, called a PEPTIDE BOND.
(Figure 3-8)
9. Amino Acids can Bond to Each Other one at a time, forming a long chain
called a POLLYPEPTIDE.
10. Proteins are compose of one or more polypeptides. Some proteins are very
large molecules, containing hundreds of Amino Acids.
11. ENZYMES - RNA or Protein molecules help control Chemical Reactions by
acting as BIOLOGICAL CATALYSTS, they are essential for the functioning of
Cells. Catalysts can Speed up some reactions by more than a billion fold.
12. Enzymes work by a Physical Fit c (Lock and Key) between the Enzyme
Molecule and its SUBSTRATE, the Reactant being Catalyzed. (Figure 3-9)
13. The Fit of Enzymes on a Substrate Weakens some chemical bonds, which
reduces the Activation Energy for the Chemical Reaction to occur. Refereed to
an the Induced Fit Model. (Figure 3-9)
14. After the Reaction, the Enzyme is Released and is Unchanged, so it can be
used many times.
LIPIDS OR FATS
1. Lipids are Large, nonpolar Organic Molecules that DO NOT Dissolve in Water.
2. Lipid molecules have a HIGHER Ratio of Carbon and Hydrogen Atoms To
Oxygen Atoms than Carbohydrates have.
3. Lipids store Energy Efficiently. They have Large Numbers of Carbon to
Hydrogen Bonds, which store More Energy than Carbon to Oxygen Bonds
common in other Organic Compounds.
FATTY ACIDS
1. FATTY ACIDS are Unbalanced Carbon Chains that make up most Lipids.
(Figure 3-14)
2. The Two Ends (HEAD AND TAIL) of a Fatty Acid molecule have different
properties:
A. The Carboxyl End (HEAD) of the Fatty Acid Molecule is POLAR, and
Attracted to Water Molecules. IT IS SAID TO BE HYDROPHILIC, WHICH
MEANS "WATER LOVING".
B. The Hydrocarbon End (TAIL) of the Fatty Acid Molecule is Nonpolar, and
tends Not To Interact with Water. IT IS SAID TO BE HYDROPHOBIC, OR
"WATER FEARING".
4. Fatty Acids are Classified as either SATURATED OR UNSATURATED. The
classification depends on the proportion of Hydrogen Atoms to Carbon - Carbon
Bonds in the molecule.
5. The FEWER the Hydrogen Atoms the MORE Double Bonds there will be
connecting the Carbons. Double Bonds can be broken and more Hydrogen's
Added.
6. FATS WITH DOUBLE BONDS ARE CALLED UNSATURATED FAT. MOST
UNSATURATED FATS ARE A LIQUID AT ROOM TEMPERATURE, AND ARE
USUALLY REFERRED TO AS OILS.
7. FATS WITH MANY DOUBLE BONDS IS A POLYUNSATURATED FAT.
8. SATURATED FATS HAVE NO DOUBLE BONDS (THEY ARE FULL)
BETWEEN THE CARBONS AND CONTAIN THE MAXIMUM NUMBER OF
HYDROGEN ATOMS.
9. SATURATED FATS ARE USUALLY SOLID AT ROOM TEMPERATURE, AND
MOST COME FROM ANIMAL PRODUCTS.
10. THREE Classes of Lipids important to Living Things contain Fatty Acids:
TRIGLYCERIDES, PHOSPHOLIPIDS, AND WAXES.
A. TRIGLYCERIDES - Composed of Three Molecules of Fatty Acids joined to
One Molecule of Alcohol Glycerol.
B. PHOSPHOLIPIDS - Have TWO Fatty Acids joined by a Molecule of
Glycerol. The Cell Membrane is composed of Two Layers of Phospholipids
called a LIPID BILAYER and forms a Barrier between the inside and outside of
the Cell. (Figure 3-11)
C. WAX - Consists of a Long Fatty Acid Chain Joined to a Long Alcohol
Chain. Waxes are highly Waterproof, in Plants and Animals they provide
Protective Coatings. Earwax prevents Microorganisms from entering the middle
ear.
11. The Last Group of Lipids are STEROIDS, Molecules that are composed of
Four Fused Carbon Rings with various functional Groups attached to them.
12. Steroids make many Human Hormones, Testosterone in Males. One of the
most Familiar Steroids in humans is CHOLESTEROL, which is needed by the
body for nerve cells and other cells to function normally.
NUCLEIC ACIDS - DNA AND RNA
1. Nucleic Acids are very Large and Complex Organic Molecules that STORE
Important Information in the Cell. (Genetic or Heredity Information)
2. Nucleic Acids use a System of FOUR Compounds to store Heredity
Information. A Sequence of the four compounds arranged in a certain order acts
as a Code for Genetic Instructions of the Cell. (adenine, guanine, cytosine,
thymine - they make up the nitrogen-containing bases found in DNA, Chap. 10-1)
3. DEOXYRIBONUCLEIC ACID, OR DNA, contains information that is essential
for almost all Cell Activities, Including Cell Division.
4. RIBONUCLEIC ACID, OR RNA, Stores and Transfers Information essential
for the Manufacturing of Proteins.
5. Both DNA and RNA are Polymers, composed of thousands of linked
Monomers called NUCLEOTIDES.
6. Each Nucleotide is made of THREE Main Components: A PHOSPHATE
GROUP, A FIVE-CARBON SUGAR, AND A RING SHAPED NITROGEN BASE.