Molecule of Life

1. Biochemistry
SB1. Students will analyze the nature
of the relationships between
structures and functions in living
cells.
b. Explain how enzymes function as
catalysts.
c. Identify the function of the four major
macromolecules (i.e., carbohydrates,
proteins, lipids, nucleic acids).
d. Explain the impact of water on life
processes (i.e., osmosis, diffusion)
Unit One: Biochemistry

2. Essential Questions
 EQ # 1 What are the properties of water
that make it essential to life?
 EQ # 2 What is the role of the four
major macromolecules in the function
of living organisms?
 EQ # 3 How do enzymes function as
catalysts?

3. EQ # 1
What are the properties
of water that make it
essential to life?

4. Structure of Water and Polarity
Polarity is when molecules
have opposite charges on
each end. One side is
referred to as negative, the
other positive. Similar to
magnets.
Because of an uneven
pattern of charge, water is
called a polar compound.
Being polar allows water to
easily dissolve other polar
substances.

5. Water is called the universal
solvent because it mixes so well
with so many things. The water pulls other
substances apart to pull
their molecules to either
the positive or negative
parts of the water.
Solubility is water being
able to dissolve polar
molecules such as
sugar or salt.
Non-polar substances
such as grease and oil
do not dissolve.
The bonds that hold water molecules together are
hydrogen bonds.

6. Ice Floats – When water freezes, hydrogen bonds
lock water molecules into a crystal structure
that has empty spaces. The solid “ice” is less
dense that liquid, so ice floats.

7.  Water
absorbs and
retains heat.
This property
of water helps
organisms
maintain a
constant
internal
temperature.

8.  Water molecules stick
together. These small
drops, such as dew
drops on a flower are
pulled into a ball
shape. Cohesion is
the attraction of
particles of the same
substance.
 Water molecules stick
to other polar
substances. Attraction
between particles of
different substances is
called adhesion.

9. Essential Question #2
What is the role of the four
major macromolecules in
the function of a living
organisms?

10. 1. Monomers – a single, repeated
molecule
2. Polymer – Monomers bond to each
other to form polymers.
3. Macromolecules – large polymers
4. ATP – Adenosine Triphosphate
provides energy to all cells.
5. ATP stores energy in the bonds
between its phosphate groups.
Carbon Molecules

11. Biomolecules
 The basic units of most biomolecules
contain atoms of carbon.
 Carbon has 4 electrons so they can
form bonds with as many as four other
atoms.
 Carbon atoms form rings and chains to
form the basic units of biomolecules:
 Carbohydrates
 Lipids
 Proteins
 Nucleic Acid

12. Carbohydrates
 Definition - Carbohydrates are
molecules made of sugar.
 Building Blocks:
 The building blocks are
monosaccharides or “simple
sugars”.
 Disaccharides (two sugars) are
also considered simple sugars.
 Many sugars = polysaccharide.

13. o EXAMPLES:
o Glucose is a simple sugar.
o Sucrose is table sugar.
o Lactose is found in milk.
 Complex carbohydrates are made from
polysaccharides.
 Starch
 Plants store glucose in the form of starch.

14. Two Functions of Carbohydrates
 Energy supply
 Major source of energy for many organisms
 Plant’s store energy from the sun in the form of
glucose, converting it to starch.
 Structural support.
 Chitin and cellulose are two complex
carbohydrates that provide support.
 Shells of crabs, lobsters etc. are made of chitin.
 Cell walls of plants are made of cellulose.

15. Lipids
 DEFINITION: Lipids are large non-polar
organic molecules that do not dissolve
in water.
 BUILDING BLOCK: Lipids consist of
chains of carbon atoms bonded to each
other and hydrogen atoms. This
structure makes lipids repel water.
 EXAMPLES: Lipids include fats,
phospholipids, steroids, and waxes.

16.  Energy Stores
 The main purpose of fat is to store energy.
 Animals survive without a steady diet
because of fat storage.
 Water Barriers
 The cell’s boundary is made of
phospholipids.
Functions and Uses of Lipids

17. Proteins
 DEFINITION: Proteins are the workhorse
molecules of all living things. They are made
up of amino acids.
 BUILDING BLOCKS: Proteins are chains of
amino acids determine what proteins do.
 EXAMPLES: include meat and animal
products as well as some plants such as
beans (soy etc. )

18. Functions of Protein
 Amino Acids – There are twenty different
amino acids found in proteins.
 To get these amino acids, your body
breaks apart the proteins in the foods you
eat.
 One amino acid is linked another amino
acid in a protein by a peptide bond.

19. Nucleic Acids
 DEFINITION: A nucleic acid is a long chain of
nucleotide units. It creates your hereditary
information and helps create energy.
 The building blocks of protein are nucleotides. A
nucleotide is made up of 3 parts:
 A sugar
 A nitrogen base
 Phosphate group

20. Functions and Uses
 Hereditary information:
 DNA – deoxyribonucleic acid, molecules that
act as instructions for the processes of an
organisms life. This is called the genetic code.
 RNA – Ribonucleic acid, another nucleotide
that helps decode the information.
 Energy Carriers
ATP – adenosine triphosphate, it is a nucleotide
that helps in the process of releasing energy.

21. EQ #3
How do enzymes function as
catalysts?

22. Enzymes
 What are enzymes?
 a protein that speeds up and controls the rate
of chemical reactions in cells.
 Why do we need enzymes?
 Even when functioning normally, your cells
make poisonous chemicals. Enzymes break
down these poisonous chemicals into
harmless substances. The enzyme is not
altered by the reaction.

23. Enzymes
 What is a catalyst?
 a substance that initiates (starts) or
accelerates a chemical reaction without itself
being affected
 What is a substrate?
 the substance is the molecule on which the
enzyme acts.
 What is the product?
 The product are the molecules produced by
the reaction.

24.  The biochemical reactions that occur in
living things must occur at certain speeds,
or rates, in order for them to be useful.
 The rate at which a chemical reaction
occurs depends on several factors:
 Temperature
 Concentration
 pH

25. Brief Review of pH scale
 Hydronium ions are in acids.
 Hydroxide ions are in bases.
 Both react together to make water.

26. Reactants →Products
 The substances that ENTER into a
chemical reaction are called the reactants.
 For the chemical reactions to occur, the
reactants must come together with enough
energy to break existing bonds and form
new ones.
 The substances formed are called
products.

27. The surface of the enzyme has a distinct shape
that allows it to interact with only certain
substrates. A single organism may possess
thousands of different enzymes. Each one is
specific to a certain chemical reaction.
The substrates bind to a part of the enzyme called
the active site. The shape of the substrates and
the shape of the active site are opposite, or
complementary. The enzyme and substrates fit
together much like a lock and key.

28. If enzymes are not used during a
chemical reaction, how do they
speed up the rate of a reaction?
 The enzyme is unchanged after the
process. They provide the reaction site.
Enzymes reduce the amount of energy
that substrates need to react.
 Enzymes reduce the activation energy,
which is the minimum amount of energy
that colliding molecules must possess in
order to react.

29. CO2 + H2O →H2CO3
Example – Some enzymes are essential for the
human body to function. Carbon dioxide in the
blood combines with water to for carbonic acid.
The reaction occurs so slowly that if it were not
catalyzed, carbon dioxide would build up in the
bloodstream faster than it could be removed.
However, the blood contains an enzyme called
carbonic anhydrase. This makes the reaction
happen about a million times faster than it
would on its own. As a result, carbon dioxide,
which in high concentration is toxic, is quickly
removed from the blood.

30. What effects enzymes?
 Temperature – Enzymes work best at certain
temperatures. The optimum temperature for
humans is 37°C. (Body temperature). Enzymes
are destroyed at temperatures over 50°C.
 pH – the pH of a solution describes how acidic
or basic the solution is. Most enzymes function
in a very narrow pH range, which varies on the
enzyme and its job. The optimum pH is 7 for
most enzymes.

31.  Concentration –
When temperature and pH are controlled, the
concentration of the enzyme and substrate
molecules are another factor. If the
concentration is high, then the reaction will
rise until all the reactions are finished.