Organic Compounds
The Big Four
Objectives:
- Highlight the similarities between protein, nucleic acid,
lipids and carbohydrates
- Examine amino acid structure and amino acid chains
- Determine the function and shape of proteins and why
they are Mr. Swift’s favourite.
What are the Big Four?
• The big four refer to the four organic
compounds found in living things. They
include:
– Proteins
– Nucleic Acids
– Lipids
– Carbohydrates
Similarities in the Big Four
• They all have carbon as their core structure
• Contain hydrogen, oxygen and several other
atoms.
• They are called macromolecules (means giant
molecules) and are made from thousands of
smaller molecules.
• The smaller units are called monomers and
they join together to form polymers.
Polymer
Monomer
• Protein
• Amino acids
• Nucleic Acids
• Nucleotides
• Lipids
• Glycerol and Fatty Acids
• Carbohydrates
• Glucose
Proteins
• Proteins have amino acids as their basic structure
• Only 20 amino acids
• Amino acids are all similar in structure. They all
have:
1.
2.
3.
4.
5.
Central carbon atom
Carboxylic acid group
Amine group
Single hydrogen atom
R group
• An R group is an arrangement of different atoms
Proteins
Drawing an Amino Acid
Proteins
Glycine
Proteins
• Circle the two you want
to memorize
• Star methionine
Proteins
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Dehydration Synthesis
Dehydration refers to a loss of water
When one amino acid joins to another, the
carboxyl group of the first bonds to the amine
group of the second.
This produces a peptide bond.
Water is released in this process.
Proteins
Glycine + Glycine → Gly-Gly + H2O
The reverse of this reaction is called hydrolysis
Proteins
• Draw the dehydration synthesis of 2 alanine
molecules.
Proteins
• 2 amino acids are a dipeptide molecule.
• More than 2 amino acids are a polypeptide
• More than 200 amino acids are a protein.
Proteins
• Draw the dehydration synthesis of an alanine
and a glycine molecule.
Functions of Proteins
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Structural molecule
Enzymes
Hormones
Antibodies
Passive and active channels in the plasma
membrane
Protein Shapes
• Primary (Linear) – the sequence of amino
acids are in a protein chain.
Protein Shapes
• Secondary (folded or helical) – the amino
acids in the chain are twisted or folded upon
themselves.
Protein Shapes
• Tertiary (3D shape) – the chain itself is folded
because of the interactions between the amino
acids with large R groups.
Protein Shapes
• Quarternary – multiple polypeptides all with a
3D shape.
Protein Video
• http://www.youtube.com/watch?v=wctkPUUpUc
Activity
• Building a quaternary protein structure
• Notice that if you press or stretch your protein
gently it springs back into place. Proteins are
somewhat flexible
• If you stretch or press it harder the protein losses
its shape and is unable to return to it’s original
configuration. This can happen to a protein that
had been altered by heat or chemical denaturation.
Review
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All organic compounds have __________ as their core element.
Large molecules made up of repeating units are called __________.
The building blocks of organic compounds are called __________.
All 20 amino acids have the same structural blueprint; a central __________,
an __________ group, a __________ acid group, a single ___________ and an
_____________.
The simplest amino acid is called ___________.
Amino acids link together in a process called ________________.
Amino acids are linked by a special covalent bond called a ____________.
The first amino acid set down in every protein is _____________.
Five important functions of my favorite organic compound are
_____________, _________________, ________________, ________________,
and ______________________________.
Protein are found in 4 shapes: ________________, ___________________,
______________________ and _____________________.
Review
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All organic compounds have Carbon as their core element.
Large molecules made up of repeating units are called Polymers.
The building blocks of organic compounds are called Monomers.
All 20 amino acids have the same structural blueprint; a central
Carbon, an Amine group, a Carboxyl acid group, a single Hydrogen
and an R-group.
The simplest amino acid is called Glycine.
Amino acids link together in a process called Dehydration Synthesis.
Amino acids are linked by a special covalent bond called a Peptide.
The first amino acid set down in every protein is Methionine.
Five important functions of my favorite organic compound are
Structural, Hormones, Enzymes, Antibodies and Carrier Protein.
Protein are found in 4 shapes: Primary, Secondary, Tertiary and
Quaternary.
Factors that Alter the Shape of Protein
• Temperature - Protein Structure
• Changes in pH – page 51 in your book
• Denaturation – temporary change in shape
• Coagulation – permanent change in shape
Page 51 in the Text book
1. What variable is plotted on the x-axis?
– Time in seconds
What variable is plotted on the y-axis?
- Pressure of oxygen in kPa
2. How did the rate of reaction change over time in
the control reaction?
– The rate was very rapid and then levelled off
3. Suggest an explanation for the change in the
control at about 40 seconds.
– The hydrogen peroxide was used up
Page 51 in the Text book
4. What effect do acids and bases have on the enzyme
catalase?
– The base makes it less effective and the acid deactivates it
so the reaction cannot take place
5. Would it be valid to conclude that if a base were added
to a reaction the rate of the reaction would slow down?
– The blue line shows that the pressure of oxygen was lower
when the base was added, so yes, this would be a valid
conclusion
6. Predict what would happen if vinegar were added to a
solution of hydrogen peroxide and catalase.
– Since vinegar is an acid, it would most likely make the
reaction not take place.
Proteins as Enzymes
• Enzymes are proteins that act as biological
catalysts
• Catalysts are substances that speed up the
chemical reaction in cells
• In chemical reactions the elements or
compounds entering into the reaction are
called the reactants, the elements or
compounds produced by the reaction are called
the products.
Proteins as Enzymes
• Only function in one chemical reaction –
specificity (lock and key principle)
• Are unaffected by the reaction, so they can be
used over again.
• If the shape of the enzyme changes, the enzyme
can’t do it’s job.
• Reduce the activation energy needed to start the
reaction
Catabolic Reactions
Anabolic Reactions
Enzymes
http://www.learnerstv.com/animation/animation.
php?ani=324&cat=biology
Review
• The big four
• Monomers and polymers
• All organic compounds have carbon as their
core structure
• Parts of an amino acid
• Dehydration synthesis and hydrolysis
• Functions of proteins
• Shapes of proteins
Review
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Denaturation and coagulation
Factors that alter the shape of proteins
Reactants and products
Specificity
Catabolic and anabolic
Objectives
• - Highlight the similarities between protein,
nucleic acid, lipids and carbohydrates
• - Examine amino acid structure and amino
acid chains
• - Determine the function and shape of proteins
and why they are Mr. Swift’s favourite.