Molecules to Metabolism – Part 1
(Section 2.1)
Important Terms
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Molecular biology
monomers
Macromolecules
polymers
Carbohydrates
vitalism
Lipids
falsification
Proteins
Nucleic acids
Anabolism
Catabolism
Metabolism
Dehydration synthesis/condensation
hydrolysis
Key concepts
• Molecular biology explains living processes in
terms of the chemical substances involved
• Car on atoms can form four bonds allowing a
diversity of compounds to exist
• Life is based on carbon compounds including
carbohydrates, lipids, proteins and nucleic
acids
• Metabolism is the web of all the enzyme
catalysed reactions in a cell or organism
Key Concepts (cont.)
• Anabolism is the synthesis of complex
molecules from simpler molecules including
the formation of macromolecules from
monomers by condensation reactions
• Catabolism is the breakdown of complex
molecules into simpler molecules including
the hydrolysis of macromolecules into
monomers
Introduction
• Humans are made up of elements. Just like
non-living things
• Question: WHAT Elements?
92% of the human body is made up of Hydrogen, Oxygen,
Nitrogen and Carbon (often called the HONC) elements
Other trace elements include phosphorus, magnesium,
sodium, potassium, calcium, chlorine, iron and sulfur
Elements of Life
• By mass, oxygen is the most abundant
element in our bodies
Elements (cont.)
• But since our bodies are made mostly of water
(H2O), hydrogen is the most abundant if we
are referring to number of atoms with ~66% of
them
Background Info
• The cell is a busy place
– Don’t believe me? Well take a look at the chart on
the next page. It shows the known chemical
reactions that take place in cells
– I found it on the internet. It’s in Vietnamese so
you can understand it better than me
Biochemical Pathways Chart
The Carbon Basis of Life
• Even though carbon is not the most abundant
element in the human body, it is perhaps the
most important
• It has a valence of 4 which means that it has
to form 4 bonds with other elements to be
part of a compound
• This makes it extremely versatile and able to
form a wide variety of compounds
Carbon (cont.)
• It forms the “skeleton” of all the major
biological molecules
• Organic chemistry is an entire branch of
chemistry that deals with the chemistry of
compounds that contain carbon
Biological Macromolecules
• Life is based on 5 basic molecules.
– One of them is water
– The other four are carbon containing compound
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Carbohydrates
Lipids
Proteins &
Nucleic Acids
Functional Groups
• Before we look at the structures of these
molecules, notice that many important
molecules contain commonly occuring small
groupings of elements
– Some of them can be found on the following page
Functional Groups
Name of Group
Structure
Example
Hydroxyl
Amine
Carboxyl
Methyl
Amino Acid
Fatty
Acid
Methane
Biochemical Molecules of Life
Molecule
Subcomponents (building
blocks)
Carbohydrate
Monosaccharide
Lipids
Glycerol, fatty acids,
phosphate groups
Biochemical Molecules of Life
Molecule
Subcomponents (building
blocks)
Proteins
(polypeptides)
Amino Acids
Nucleic Acids
Nucleotides
Carbohydrates
• A polar molecule
• Made of Carbon, Hydrogen and Oxygen in a
1:2:1 ratio
• Usually ring structure (if > 5 carbons)
• Common Monomers:
– 6 Carbons - Glucose, fructose, galactose,
– 5-Carbons – Ribose, deoxyribose
S1. Drawing Molecular Diagrams
Glucose: C6H12O6
 6 atom ring with a side chain
5 carbons are in the ring, one is with the side
chain
Carbons are numbered with 1 on the right
Hydroxyl groups on C 1,2,3, and 4
S1. Drawing Molecular Diagrams
Glucose: C6H12O6
Biologyatsandringham.pbworks.com
Carbohydrates (cont)
• Two monomers (monosaccharides) can attach
together to form disaccharides (e.g. lactose
and sucrose)
• Sucrose
Carbs (cont.)
• Many monosaccharides can attach together to
form a polysaccharide (e.g. glycogen, starch,
cellulose, chitin)
Lipids
Lipid Classification
Triglycerides: glycerol with three fatty acids
– Example: Fat stored in adipose cells
Lipids (cont.)
Lipid Classification
Phospholipids: phosphate group with two
fatty acids
– Example: Lipids forming a bilayer in cell membranes
Lipids
• Lipid Classification
• Steroids: rings of carbon with side chains
– Examples: cholesterol, vitamin D, and some
hormones
S1. Drawing Molecular Diagrams
Saturated Fatty Acid:
Carbon atoms form an unbranched chain
Number of carbon atoms is between 14 and
20
One end is a carboxyl group
The other end is a methyl group
Carbon atoms in between have 2 hydrogen
bonded
S1. Drawing Molecular Diagrams
Saturated Fatty Acid:
Courses.washington.edu
Proteins and Nucleic Acids
• Proteins:
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Examples: Enzymes, antibodies, peptide hormones
• Nucleic Acids:
– Examples: Deoxyribonucleic acid (DNA),
Ribonucleic acid (RNA), adenosine triphosphate
(ATP)
S1. Drawing Molecular Diagrams
Amino Acid:
Carbon atom in center with
Amino group
Carboxyl group
Hydrogen atom
R group (variable)
S1. Drawing Molecular Diagrams
Amino Acid:
Education-portal.com
Amino Acids