BIO.A.2.2 Describe and interpret relationships between structure
and function at various levels of biochemical
organization (i.e., atoms, molecules, and macromolecules.)
BIO.A.2.1 Describe how the unique properties of water support life on Earth.
BIO.A.2.3 Explain how enzymes regulate biochemical reactions within a cell.
What are living creatures made of???
 Living AND nonliving things are considered to be
matter.
 Matter = Anything that has mass + takes up space
 The smallest unit of matter is an ATOM, therefore
living things are made of atoms of different elements.
 ELEMENTS are made entirely of one type of atom! For
example…the element calcium is made up of only
calcium atoms!
What elements are found in living things?
 98% of living organisms is made of:
 Carbon (C)
 Hydrogen (H)
 Nitrogen (N)
 Oxygen (O)
 Phosphorus (P)
 Sulfur (S)
How do these elements get inside
living things?
 We eat, drink and breathe to
take in more of these
elements so they can be used
for the following:



to make more of us (cells)
for growth
for repair
 For example carbohydrates
contain the carbon, hydrogen
and oxygen needed by living
things.
How can nonliving ATOMS be used
to make something that is living?
 Atoms of the elements
C,H, N, O, P, S can be put
together to make living
things. The first step is to
combine ATOMS to form
MOLECULES!
 You must understand
atomic structure before
we can understand how
molecules are assembled.
Bonds
 There are different ways to bond atoms together, and each bond involves
the interaction of electrons.
 Covalent bonds – atoms SHARE electrons
 Ionic bonds – atoms TRANSFER (gain or lose)electrons
 Examples:
Covalent Bond
Ionic Bond
 Molecules are formed by covalent bonds. What molecule is formed in the
picture of the covalent bond above?
Ions
 Ion: An atom that has gained or lost one or more electrons. Remember
atoms are neutral overall; however if they lose or gain one or more
electrons they become charged. Check out the examples below.
 Ions are important in living things.
 Cl 1- = chloride ion  needed for brain function
 Na 1+ = sodium ion  helps maintain electrical (nerve) impulses
 K 1+ = potassium ion  helps maintain electrical (nerve) impulses
 Ca 2+ = calcium ion  needed for muscle movement
 What is the difference between
a calcium atom and a calcium ion?
Sodium atom vs. sodium ion?
Molecules
 MOLECULES are composed of two or more atoms held
together by covalent bonds (bonds that involve the
sharing of electrons).
 Can you name these common molecules found in
living things?
Biological Macromolecules
 Up to this point we have learned that atoms bonded
together make molecules…So what do molecules
bonded together form???? MACROMOLECULES
 Biological macromolecules are large molecules that are
found in living things. They are necessary for living
things to live and function. There are four main types
of biological macromolecules, which include:
1.) Carbohydrates
2.) Proteins
3.) Lipids
4.) Nucleic Acids
Building Macromolecules
BIO.A.2.2.2 Describe how biological macromolecules
form from monomers.
How are biological macromolecules formed?
 Smaller molecules are bonded together to form bigger
molecules in a process called SYNTHESIS!
 The smaller building block molecules are called monomers.
 The larger molecules that are formed are called polymers.
Monomer
Polymers
Building Biological Macromolecules
 Carbohydrates = building blocks are simple sugars
sugar – sugar – sugar – sugar – sugar – sugar
 Proteins = building blocks are amino acids
amino amino amino amino amino amino
acid – acid – acid – acid – acid – acid
 Nucleic acids = building blocks are nucleotides
nucleotide – nucleotide – nucleotide – nucleotide
 Lipids = building blocks are fatty acids & glycerol
fatty acid – fatty acid – fatty acid – fatty acid – fatty
Dehydration Synthesis Vs. Hydrolysis
Dehydration Synthesis
 Process that forms polymers
 Process used to make DNA, RNA, enzymes,
antibodies, cellulose, hemoglobin, starch
 monomer + monomer  polymer + H2O
 Ex.) building muscle, new cells, etc…
Hydrolysis
• Process that breaks down polymers
• Polymer + H2O  monomer + monomer
• Ex.) digestion
+
Importance of Carbon
BIO.A.2.2.1 Explain how carbon is uniquely suited to
form biological macromolecules.
The Importance of CARBON
 Carbon is an extremely important element because of its
bonding capabilities. Carbon is able to form four bonds
which makes it uniquely suited to form macromolecules.
 The macromolecules formed by carbon are usually:
 Large
 Complex
(Rings & Chains)
 Diverse (Many functions)
black atoms = carbon
Let’s take a closer look…..
 Molecules w/ carbon = organic molecules
 Molecules without carbon = inorganic molecules
 Organic OR Inorganic:
 CO2 - Carbon dioxide
 NaCl - Table Salt
 O2 - Oxygen
 C6H12O6 - Glucose
 H2O - Water
 Are biological macromolecules (proteins, lipids,
carbohydrates and nucleic acids) organic or inorganic?
Biological Macromolecules
BIO.A.2.2.3 Compare the structure and function of
carbohydrates, lipids, proteins, and nucleic acids
in organisms.
Identifying Monomers by Structure
What macromolecules will they form?
Does it have a ring
structure in its main
chain?
Carbohydrates
(Polysaccharides)
STRUCTURE
 Contain the elements:
 Carbon
 Hydrogen
 Oxygen
 Usually form a ring-like pattern.
 Carbs are made from monomers
called simple sugars
(monosaccharides).
 Examples include starch,
cellulose, glycogen,
polysaccharides (complex
sugars)
 Found in foods such as breads,
grains, vegetables, fruit and milk.
FUNCTION
• Provides energy for cell functions
• Important component in plant cell
structure & some animal cell structure
STRUCTURE
 Contain the elements:





Proteins
Carbon
Hydrogen
Oxygen
Nitrogen
Sulfur (sometimes)
 Proteins are made up of monomers
called amino acids. Amino acids have an
amino group (-NH2) and a carboxyl
group (-COOH)There are 20 different
amino acids that are held together by
special bonds called peptide bonds.
 Proteins form complex folded
polypeptide chains.
 Examples include:
 Antibodies (part of the immune
•
•
system)
 Hemoglobin (part of the blood)
 Enzymes (speed up chemical reactions
like digestion)
•
•
 Found in foods such as meats, nuts, eggs
and fish.
•
FUNCTION
Help to build and repair cells.
Help to speed up chemical
reactions in living things.
Help make antibodies (fight disease).
Help transport molecules
across plasma membranes.
Found in muscles, hair, nails.
Lipids
Structure
Function
• Secondary source of energy for cells
• Main component of plasma (cell)
membranes
• Help to insulate living things
 Contain the elements:
 Carbon
 Hydrogen
 Oxygen
 Usually form long straight chains
or branching chains.
 Lipids are made from monomers
of fatty acids and glycerol.
 Examples include:






Oils
Fats
Cholesterol
Triglycerides
Phospholipids
Waxes
Structure
 Contain the elements:
 Carbon
 Hydrogen
 Oxygen
 Nitrogen
 Phosphorus
 Nucleic acids are made of monomers
called nucleotides. Nucleotides contain a
5-carbon sugar, phosphate group (-PO4)
and nitrogen base. There are 5 types of
nucleotides:
 Adenine
 Guanine
 Cytosine
 Thymine
 Uracil
 Examples of nucleic acids include:
 DNA (deoxyribonucleic acid)
 RNA (ribonucleic acid)
Nucleic Acids
Function
• DNA stores genetic information
• RNA helps build proteins
The Importance of Water
BIO.A.2.1.1 Describe the unique properties of water and
how these properties support life on Earth (e.g., high
specific heat, adhesion, cohesion).
Water AND Living Things
 Why is water important to living things?
1.) Water is necessary for aquatic ecosystems…
 Saltwater habitats
 Freshwater habitats
2.) Living things consist of approximately 70% water.
 Water helps to dissolve substances (vitamins, minerals, etc…) in living
things.
 Water helps to transport substances (nutrients & waste) in living
things.
 Water acts as a product or a reactant in many biochemical reactions
such as photosynthesis, cellular respiration, dehydration synthesis
and hydrolysis that occur in living things.
 Water helps maintain adequate temperature in living things.
 Enzymes rely on water in order to function properly in living things.
Water Molecules
 Water is a polar molecule. Polar molecules have
slightly charged regions.
 Water has a slightly negative oxygen region and two
slightly positive hydrogen regions.
Hydrogen Bonding
 Remember… a water molecule is held together by covalent bonds.
Electrons are shared between the oxygen and hydrogen atoms of a water
molecule.
 What holds one water molecule to another molecule???
The answer is…….HYDROGEN BONDS! Hydrogen bonds are bonds that
form between a slightly positive hydrogen atom and another slightly
negative atom.
 Where are the hydrogen bonds below? How many hydrogen bonds can
be formed by one water molecule?
Properties of Water
 Some properties of water are related to water’s ability to
form hydrogen bonds. These properties of water include:
 High specific heat: resists changes in temperature
 Cohesion: attraction of water to other water molecules
 Adhesion: attraction of water molecules to different molecules
Additional Properties of Water
 High Surface Tension: The molecules on the surface of a body




of water are cohesive and form a surface “film.”
High Heat of Vaporization: The amount of heat needed to
turn a substance from a liquid state into its gaseous state.
Maximum density at 4° C : Water is more dense as a liquid
instead of a solid. (At what temp does water freeze? Does ice
float or sink? Is ice more or less dense than liquid water?)
Universal Solvent: Water is the most commonly used solvent
(liquid used to dissolve other substances).
Capillary Action: Cohesion and adhesion work together to
draw a liquid up a narrow tube or opening.
Identifying Properties of Water
 Identify which property/properties of water is
displayed in each picture?
Water = The Universal Solvent
 Solution: substance formed when one substance is
dissolved in another substance.
 Solvent: substance that does the dissolving
 Solute: substance that gets dissolved
solution
 Identify examples of solutes? Solvents?
Solutions versus Suspensions
 Solutions (mix evenly throughout)
 Polar solvents dissolve polar solutes.
 Non-polar solvents dissolve non-polar
solutes.
 Suspensions (do NOT mix evenly
throughout)
 Polar solvents do NOT dissolve nonpolar solutes; therefore they separate.
 Non-polar solvents do NOT dissolve
polar solutes; therefore they separate.
pH of Solutions
 pH = measure of the concentration (amount) of hydrogen ions in a solution.
 Acid: releases a hydrogen ion when it dissolves in water.
high H+ concentration
 pH less than 7
 Base: releases hydroxide ions and removes hydrogen ions from a solution.
 low H+ concentration
 pH greater than 7

Why is pH important to living things?
 Most living things can only live in a narrow pH
range.
 Enzymes cannot function properly when
pH fluctuates too much. Most human cells
range between 6.5 and 7.5.
 If pH fluctuates too drastically the
chemical reactions within cells are altered.
 One way organisms control pH is through
dissolved compounds called BUFFERS.
Buffers are weak acids or weak bases that
help neutralize strong acids and bases.
Buffers help us maintain homeostasis
by controlling pH.
 Review the handouts “Why is pH
important to living things?”
Enzymes
BIO.A.2.3 Explain how enzymes regulate biochemical
reactions within a cell.
BIO. A.2.3.1 Describe the role of an enzyme as a catalyst in
regulating a specific biochemical reaction.
BIO.A.2.3.2 Explain how factors such as pH, temperature
and concentration levels can affect enzyme function.
Enzymes
 Enzymes are proteins that act as biological catalysts. (Catalysts
are substances that speed up the reaction rate of chemical
reactions.)
 Enzymes are usually named after the reaction they catalyze. They
also typically end in –ase. For example:
 Lipase = enzyme which speeds the breakdown of lipids (fats)
 Protease = enzyme which speeds the breakdown of proteins
 DNA polymerase = enzyme which speeds the construction of
the polymer DNA
lipase
protease
Different structures = different functions
Enzymes
 Enzymes are very specific, generally catalyzing only one chemical reaction.
For example:
 The enzyme maltase speeds up the breakdown of maltose into separate
glucose molecules.
 The enzyme maltase binds with the substrate (reactants = maltose) at a
specific location called an active site in order to form glucose. Specific
enzymes and substrates fit so perfectly together that they are referred to as a
Lock and Key Model.
Lock and Key Model
Substrates bind to an
enzyme at certain
places called active
sites.
The enzyme brings
substrates together
and weakens their
bonds.
The catalyzed reaction forms
a product that is released
from the enzyme.
Regulation of Enzyme Activity
 Enzymes play essential roles in controlling chemical pathways, making
materials that cells need, releasing energy, and transferring
information; therefore it is important to keep them functioning
properly.
 A variety of factors affect the activity and ability of enzymes to function
properly. These factors include:
 Temperature
 pH
 Concentration
 Enzymes function best in a narrow range of temperature, pH and
concentration. If the temperature, pH or concentration fluctuates
outside of this range the shape of the enzyme may change and the
result is an enzyme incapable of performing its job.
 Remember…ENZYME FUNCTION DEPENDS ON ITS STRUCTURE!!!!