Vocabulary
Polarity
Concentration
4 carbon compounds monosaccharide lipid enzyme
Hydrogen bond
Solution monomer polysaccharide fatty acid catalyst
Adhesion
Solute
Cohesion
Solvent polymer carbohydrate amino acid protein nucleic acid nucleotide pH specific heat
Nearly 75% of our earth is covered in water.
Our bodies are 60-65% water. Our blood is 85% water.
None of the many reactions that occur in our bodies would occur without water.
Composition of water: H
2
O

Water is POLAR.
The diagram shows that one side of the water molecule is positively charged and the other is negatively
charged.
The molecule itself is neutral. These opposite charges make water a polar molecule.

Water undergoes ADHESION and COHESION due to its polarity.
The negative oxygen of one water molecule is attracted to the positive hydrogen of another molecule forming a hydrogen bond. In other words water likes to stick to itself. Water sticking to water is called
cohesion. Water’s polarity allows it to attract to other surfaces too (like glass). Water sticking to something else is called adhesion.
1.
In the diagram to the right use dotted lines to draw in the bonds that form between water molecules.
Positives connect to negatives, up to four bonds per water molecule.
2.
What is the name of this type of bond?
Hydrogen or “H” bond
3.
What special property do the bonds give to water.
Several: cohesion first and foremost (water sticking to itself).
Creates surface tension on the water (water skipper can seemingly “walk” on water


Water has a HIGH SPECIFIC HEAT.
Hydrogen bonds also give water a high specific heat . Water can absorb a great amount of heat. It takes a lot of energy input to change the temp. of water. This allows water to regulate temperature of the Earth and also our bodies.
Specific heat is the amount of energy required to raise one gram of water 1 degree Celsius.
8.
Can you think of a reason why water can absorb so much heat? Hint – think bonds
Hint – think bonds
Before water boils or undergoes and extreme temperature change hydrogen bonds must be broken. Weak hydrogen bonds give water a high specific heat.

Water EXPANDS WHEN IT FREEZES. Ice is therefore less dense than water. ICE FLOATS in water.
This is also due to hydrogen bonding. Molecules freeze in a rigid structure and expand.
9.
Challenge yourself to think of two ways that specific heat and the freezing point of water help support life on earth.
Specific heat: keeps aquatic environments from experience extreme temperature fluctuations, changes are gradual.
Ice expands when frozen, floats on surface water bodies and insulates aquatic organisms from extreme cold.
Use the diagrams below to fill in the blanks and describe why carbon is so important to life.
Figure 2: Covalent
Bonding between
Carbon and Hydrogen

Figure 1: Carbon Atom
 Carbon has ______ 4 ________ in the outer
(valence) shell o Valence shell enables easy formation of four covalent bonds o Covalent bonds involve ____ sharing _____ of ___ electrons___ between two atoms
 Carbon has the ability to form ______ long chains_ ___________________ by forming several bonds in a row

Variety is created by the many partners that carbon can bond with
 Small carbon compounds called monomers link together to form large carbon compounds called polymers. Each of the 4 carbon compounds has a monomer that links together to make the macromolecule (polymer).
 Monomers bond together to make polymers by dehydration synthesis.
 Polymers can be broken down into monomers by hydrolysis.

Class
Carbohydrates
Lipids
Proteins
Nucleic acids
Macromolecules and Their Function
Monomers Functions
Monosaccharides Energy, raw materials, energy storage, structural compounds
Energy storage, membranes, steroids, hormones Glycerol, fatty acids, steroids
Amino acids
Nucleotides
Enzymes, transport, movement, receptors, defense, structure
Heredity, code for amino acid sequence

_ Dehydration synthesis _ breaks down carbohydrates into monosaccharides like glucose.

Glucose is used in ___ Cell Respiration ____ and converted to __ ATP __ for energy.

Excess glucose is bonded together to form a polymer called _____ glycogen _______ and stored in ____________, ____________ and then _____________.

 Lipids are nonpolar macromolecules made from long carbon chains
 Lipids can be fats, phospholipids, or steroids
 Fats act as storage of material that can be used for energy.
 ____ Phospholipids _________ compose cell membranes
 Lipids can be ___ saturated __________ or
_____ unsaturated _________

Protein is the main unit of structure and function in the
body.

Amino acids are made up of a carbon attached to
_____ Amino _________ and ____ Carboxyl _______ groups. They are made unique by the “R” group that is attached to the carbon.
 There are __ 20 __ amino acids.
 __ DNA _____ codes for the amino acid sequence of each protein in the body.

 Nucleic acids are polymers of nucleotides

Nucleotides are monomers that consist of pentose sugar (the hexagon shape in the diagram) attached to a phosphate group (in red on diagram) and nitrogen base (in blue on diagram)

The sugar can be deoxyribose (as in DNA or__ deoxyribose nucleic acid __) or ribose (as in
RNA or __ ribose nucleic acid __)

DNA and RNA are central to heredity and are made unique by the nitrogenous ___ base____ that is attached

Nitogenous bases can be cytosine (C), thymine (T), uracil (U), adenine (A), or guanine (G)

Enzymes are proteins that act as biological catalysts

Catalysts increase the rate of a reaction without being changed by the reaction

Substrates are the reactants on which enzymes work

Rate of reaction in both directions (oxidation or reduction) is increased by the presence of specific enzymes.

__ Active _______ __ Site ___ refers to the part of an enzyme that interacts with a substrate, where the substrate fits


Enzyme reaction rates are impacted by temperature, pH & substrate concentration

Temperature is a measure of kinetic energy o Kinetic energy is the energy of motion. Higher temperature means __ faster _____ moving particles. o The number of collisions between enzymes and substrates is increased if the particles move around __ faster_ _ (higher temperature) o Our enzymes do not function well above or below the ___ optimal (best)_______ temperature o The enzyme denatures, or breaks down, if the enzyme gets too ___ hot or cold ___

pH measures acidity o Each enzyme has a specific pH at which it functions best o If the conditions are too acidic (low pH) or too basic (high pH), the enzyme may denature

Concentration is a measure of how many substrate molecules are present in a given volume. o Higher concentration of substrate means more substrate finding the active site. o Production speeds up.
Practice Questions:
1.
Which statement correctly describes how carbon’s ability to form four bonds makes it uniquely suited to form macromolecules?
A.
It forms short, simple carbon chains.
B.
It forms large, complex, diverse molecules.
C.
It forms covalent bonds with other carbon atoms.
D.
It forms covalent bonds that can exist in a single plane.
2.
What reaction or process forms a polymer from 2 monomers?
A.
glycolysis
B.
hydrolysis
C.
photosynthesis
D.
dehydration synthesis

3.
Carbohydrates and proteins are two types of macromolecules. Which functional characteristic of proteins distinguishes them from carbohydrates?
A.
large amount of stored information
B.
ability to catalyze biochemical reactions
C.
efficient storage of usable chemical energy
D.
tendency to make cell membranes hydrophobic
4.
Substance A is converted to substance B in a metabolic reaction. Which statement best describes the role of an enzyme during this reaction?
A.
It adjusts the pH of the reaction medium.
B.
It provides energy to carry out the reaction.
C.
It dissolves substance A in the reaction medium.
D.
It speeds up the reaction without being consumed.
5.
A scientist observes that, when the pH of the environment surrounding an enzyme is changed, the rate the enzyme catalyzes a reaction greatly decreases. Which statement best describes how a change in pH can affect an enzyme?
A.
A pH change can cause the enzyme to change its shape.
B.
A pH change can remove energy necessary to activate an enzyme.
C.
A pH change can add new molecules to the structure of the enzyme.
D.
A pH change can cause an enzyme to react with a different substrate.
6.
Whenever biological organic compounds, such as proteins and carbohydrates, are broken down or synthesized... a.
a phase change of matter results. b.
thermal expansion occurs. c.
sunlight is required. d.
energy is absorbed or released.
7.
Why does an enzyme function as a catalyst in a reaction? a.
It creates the right pH needed for the reaction. b.
It decreases the amount of energy needed for the reaction. c.
It provides the extra energy needed for the reaction. d.
It maintains the proper temperature needed for the reaction.
Examine the structural formula below.
8.
Which of the following macromolecules is best represented by this formula? a.
nucleic acid c. protein

b.
carbohydrate long chain fatty acids (blue) d. lipid (remember lipids are made of one glycerol (red) and three
Open-ended Question:
9.
Proteins are a major part of every living cell and have many different functions within each cell.
Carbohydrates also perform numerous roles in living things.
Part A: Describe the general composition of a protein molecule.
_____ Proteins are made from carbon, oxygen, hydrogen, nitrogen and some have sulfur. These elements form amino acids. Amino acids form proteins.
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Part B: Describe how the structures of proteins differ from the structures of carbohydrates.
______ Carbohydrates are in long chains formed by sugars that have bonded together. Proteins can be in sheets or folded shapes. Carbohydrates only have carbon, hydrogen and oxygen in them.
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Part C: Describe how the functions of proteins differ from the functions of carbohydrates
_________ Proteins make up the reactions that speed up reactions in living things. Proteins also make antibodies. Carbohydrates give us energy (starch, glycogen) and make up plant cell walls
(cellulose)
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