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Biochemical Compounds
You are what you eat!!
Essential Questions:
1.
What are the 4 main types of biological
macromolecules and what is their
function within cells?
2.
How does the structure of each
macromolecule contribute to their
function within cells?
3.
What are the 4 major types of
biochemical reactions and why are they
important to normal cellular function?
Carbon: The Central Atom
What’s so special about
?
The diversity of life relies on carbon!!!
 Virtually all chemicals of life are carbon based
(exceptions – e.g., H2O, CO2) – called organic compounds.
 It can form four covalent bonds (H, O, N, P, S, C)
 C-C bonds enable carbon to form a variety of
geometrical structures (e.g., straight chains, branched
chains, rings)
Methane
CH4
+ CH2
Ethane
C2H6
+ C4
Benzene
C6H6
Molecular Isomers: The same, yet different
What’s so special about
?
Isomer – an organic compound with the same
molecular formula, but different structure
Example:
C6H12O6
C
C
Glucose
(simple sugar)
Fructose
(fruit sugar)
Galactose
(milk sugar)
C
C
C
C
C
C
C
Structural isomers
Metabolized by cells differently due to structure
Molecular Isomers: The same, yet different
What’s so special about
?
Isomer – an organic compound with the same
molecular formula, but different structure
Stereoisomers
Structural isomers
Same atoms,
Same bonds,
Differently arranged in space
Same atoms,
bonded differently
Geometrical
Optical
Molecular Isomers: The same, yet different
What’s so special about
?
Isomer – an organic compound with the same
molecular formula, but different structure
Stereoisomers
Carvone
Same atoms,
Same bonds,
Differently arranged in space
Geometrical
Optical
Macromolecules
What is the relationship between atoms, bonding and
macromolecules?
Atoms
join together
Bonds
that form
Molecules
that form large structures called
Macromolecules
Macromolecules and their subunits
Monomer + Monomer + Monomer = Polymer = Macromolecule
smaller subunits
long chain
of monomers
glycogen
glucose
Macromolecules and their subunits
Carbon
Compounds
1
2
Carbohydrates
Lipids
Which are made of
Which are made of
Simple sugars
(e.g., glucose)
which contain
Carbon,
hydrogen,
oxygen
main function
include
Glycerol &
3 Fatty Acids
which contain
Carbon,
hydrogen,
oxygen
main function
ENERGY
STORAGE
ENERGY
STORAGE
short-term
long-term
3
Nucleic acids
(e.g., DNA/RNA)
Which are made of
Nucleotides
which contain
Carbon, hydrogen
oxygen, nitrogen,
phosphorus
main function
ENCODING
HEREDITARY
INFORMATION
4
Proteins
Which are made of
Amino Acids
which contain
Carbon,
hydrogen, oxygen,
nitrogen,
main function
CATALYSIS
&
STRUCTURE
/SUPPORT
Carbohydrates
 Main Function:
quick and short-term energy storage
Carbon
(4 cal/g)
Compounds
 Groupings: C, H, and O atoms
1
include
2
Carbohydrates
Simple sugars
(e.g., glucose)
which contain
Carbon,
hydrogen,
oxygen
main function
short-term
3
 Two types: 1. Simple Carbohydrates
Nucleic acids
Which are made of
ENERGY
STORAGE
(1 : 2 : 1 ratio)
Lipids
2. Complex Carbohydrates
Which are made of
Glycerol &
3 Fatty Acids
which contain
Carbon,
hydrogen,
oxygen
Which are made of
Nucleotides
which contain
Carbon, hydrogen
oxygen, nitrogen,
phosphorus
4
Proteins
Which are made of
Amino Acids
which contain
Carbon,
hydrogen, oxygen,
nitrogen,
Carbohydrates – Simple (glucose)
 Carbohydrate molecule with 3-7 carbon atoms is called a
monosaccharide. (mono = one, saccharide = sugar)
 Broken down quickly in the body to release energy.
e.g., GLUCOSE – hexose (six-carbon) sugar with 7
energy-storing C-H bonds
6
5
4
1
3
Primary source of energy
used by all cells
2
C6H12O6
(ring structure – when dissolved in water)
MONOSACCHARIDES
QUIZ: Select the formula that represents a monosaccharide
C4H8O4
C5H10O10
C6H6O12
C6H6O6
Making & Breaking Carbohydrates
monosaccharide + monosaccharide
disaccharide (di = two)
Condensation (dehydration) synthesis
Hydrolysis
Two important
biochemical reactions
Carbohydrates – Complex (Polysaccharides)
 Main Function: quick and short-term energy storage
 Contain many units of glucose in long chains
 Examples: Starch, glycogen, cellulose
Starch = energy storage in
plants
Starch Granules (purple) in Potato Cells
Carbohydrates – Complex (Polysaccharides)
Glycogen (polymer)
Glucose (monomer)
Glycogen = energy storage
in animals
muscle
liver
Glycogen (red) in Hepatocytes (liver cells)
Carbohydrates – Complex (Polysaccharides)
Cellulose fibers
Cellulose = polysaccharide
found in plant
cell walls
Macrofibril
Microfibril
Chains of
cellulose
Carbohydrates – Complex (Polysaccharides)
What is the difference between starch and cellulose?
Starch
Cellulose
Starch
Glucose repeat
units are facing
the same
direction
Enzymes to digest
Soluble
Weaker
Cellulose
Both polymers
Same monomer
(glucose)
Each successive
glucose unit is
upside-down in
relation to each of
the glucose
molecules that it
is connected to
Cannot digest (no enzymes)
Same repeat base
Insoluble (fiber / roughage)
Stronger (good for building)
Lipids (fats)
 Main Function: long-term energy storage
2
Lipids
 Special3Feature: contain more
4 energy per gram than
any other biological molecule (9 cal/g)
Nucleic acids
Proteins
(e.g., DNA/RNA)Mostly C and H atoms (hydrocarbons)
 Groupings:
Which are made of
Glycerol &
3 Fatty Acids
Which are made of
Which are made of
 Types: 1. Fats and oils
which contain
Carbon,
hydrogen,
oxygen
3. Steroids
Amino
Acids
Nucleotides
2. Phospholipids
4. Waxes
which contain
Carbon, hydrogen
oxygen, nitrogen,
phosphorus
main function
which contain
Carbon,
hydrogen, oxygen,
nitrogen,
main function
main function
ENERGY
STORAGE
long-term
CATALYSIS
ENCODING
&
HEREDITARY
STRUCTURE
Plant oils (liquid @ room temp)
INFORMATION
/SUPPORT
Animal fat (solid @ room
temp)
Structure of Lipids (fats)
1
2
3
Glycerol
Fatty acids
Glycerol
FA
FA
= TG (Triglyceride)
FA
Lipid droplet
TG TG
TG
TG TG
TG
Adipocytes (rat)
Courtesy of Dr. Ceddia – York University
Making and Breaking Lipids (fats)
Fats and oils are called triglycerides because of their structure
What functional groups are
present on the glycerol and
fatty acid molecules?
Ester linkage
Hydrolysis
Condensation
Synthesis
+ 3 H2O
Saturated
Unsaturated
Polyunsaturated
# of double bonds
between carbons
Orientation
State at Room
Temp.
Origin
Which are better
for you?
Example
Types of Fatty Acids
Types of Fatty Acids
Poly Saturated Unsaturated
unsaturated
# of Double
At least one
None
Bonds
Several
double bond
(contains
between
double bonds
between
maximum #
Carbons
carbon atoms
of H atoms)
Types of Fatty Acids
Fewer hydrogens – “unsaturated”
Types of Fatty Acids
Poly Saturated Unsaturated
unsaturated
Orientation
Straight
of Fatty
chains
Acids
Kinks /
Kinks /
bends at
bends at
the double the double
bonds
bonds
Types of Fatty Acids
CH2-CH
BEND DUE
TO
DOUBLE
BOND
Types of Fatty Acids
Poly Saturated Unsaturated
unsaturated
Examples
butter,
lard
olive oil, vegetable oil,
peanut oil, canola oil
Types of Fatty Acids
Trans Fat
Taking a perfectly good fat
and making it bad!
Addition of hydrogen atoms to the acid, causing double
bonds to become single ones.
(unsaturated becomes saturated)
LDL
HDL
Phospholipids
 Fat
derivatives in which one fatty acid
has been replaced by a phosphate
group and one of several nitrogencontaining molecules.
 an important part of the cell membrane
(phospholipid bilayer)
Phospholipids
Phospholipids
Nitrogen-containing
group
Phospholipids
The phospholipid can also be represented as:
Polar Head – hydrophilic
(water-loving)
Non-Polar Tails (fatty acids) –
hydrophobic (water-hating)
Steroids
Steroids consist of 4 fused carbon rings
Testosterone
Cholesterol
• Precursor for other steroids
• Component of animal cell membranes
• Contributes to atherosclerosis
Proteins
Proteins are essential parts of living organisms and
participate in virtually every process in cells.
Types
Function/Example
Enzymatic
Acceleration of chemical reactions
E.g., digestive enzymes, cellular respiration
Amino Acids
Structural
Collagen & elastin, keratin in hair and nails
which contain
Transport
Transport of other substances
E.g., hemoglobin transports O2 to cells
Hormonal
Cellular communication
E.g., insulin secreted by the pancreas
Contractile
Movement
E.g. actin and myosin in muscle cells
Defensive
Protect against disease
E.g., antibodies combat viruses and
bacteria
Proteins
Which are made of
Carbon,
hydrogen, oxygen,
nitrogen,
main function
CATALYSIS
&
STRUCTURE
/SUPPORT
Proteins and their subunits
Amino acids are the building blocks of proteins
Amino Acid Structure
Amino Group
Any one of the 20 different
side-chains
Carboxyl (acid) G
Proteins and their subunits
Examples of amino acids
Fig. 1.14B, pg
Proteins and their subunits
20 Major Amino Acids
8 are considered “essential”
1. Phenylalanine
2. Valine
3. Threonine
4. Tryptophan
5. Isoleucine
6. Methionine
7. Leucine
8. Lysine
Fig. 1.14B, pg
The other 12
1. Glycine
2. Alanine
3. Proline
4. Serine
5. Cysteine
6. Asparagine
7. Glutaimine
8. Histidine
9. Tyrosine
10. Aspartic acid
11. Glutamic acid
12. Arginine
Types of Amino Acids
Nonpolar
Polar
Polar/Acidic
Polar/Basic
Amino acids each have their own unique
chemical properties.
Some dissolve in water – some do not.
This is essential for transport and storage.
Making and Breaking Proteins
Amino acids are linked together by peptide bonds
- a special covalent bond found in proteins
+
H2O
Dipeptide
Peptide bond
Making and Breaking Proteins
Condensation synthesis
• two amino acids join (dipeptide)
• a peptide bond is formed
• a water molecule is formed
Hydrolysis
• water is added
• a peptide bond is broken
• amino acids are split apart
A chain of amino acids is called a polypeptide
Gly
H2Nend
Lys
Phe
Arg
Peptide Bonds
Ser
-COOH
end
Making and Breaking Proteins
A chain of amino acids is called a polypeptide
Gly
H2Nend
Lys
Phe
Arg
Peptide Bonds
Ser
-COOH
end
The type of protein is determined by:
 sequence of polypeptides
 orientation in space
3-D shape
Four levels of protein structure:
Primary - exact sequence of amino
acids before folding.
Secondary - simple folding create
simple structures.
Tertiary - folding results in complex 3D
structures.
Quaternary - multiple 3D subunits
organized into a bigger
structure.
Sulfhydryl (-SH) functional groups
can form disulfide (-S-S) bonds
which contribute to a proteins
tertiary structure.
Hemoglobin
Carries oxygen in the blood
- It's made up of 4 specific 3D subunits
Proper protein function depends
on correct 3D structure.
Any change in the specific primary structure can cause
the protein to fold differently.
A different shape can lead to a
different function
(or lack of proper function).
Sickle cell anemia is an example.
Nucleic Acids
Nucleic acids are macromolecules composed of
chains of nucleotides.
Nucleic acids
 Nucleic acids carry genetic information
(e.g., DNA/RNA)
Which are made of
Nucleotides
which contain
Types:
Carbon, hydrogen
oxygen, nitrogen,
phosphorus
 DNA (deoxyribonucleic acid)
main function
ENCODING
HEREDITARY
INFORMATION
 RNA (ribonucleic acid)
Types of Nucleic Acids
DNA
 Long-term storage of
hereditary information
 Carries genetic
instructions or “blueprints”
for building parts of the cell
 Segments of DNA are
responsible for carrying
genes (genetic information),
have structural purposes, or
regulate the use of genetic
information
RNA
 Involved in the process of
transcribing genetic
information from DNA into
proteins
 Protein synthesis (the
process of making proteins)
is carried out by organelles
called ribosomes, which take
“instructions” from RNA
DNA & RNA Nucleotide
Phosphate
Group
O
O=P-O
O
5
CH2
O
N
Sugar
(deoxyribose
or ribose)
C1
C4
C3
C2
Nitrogen base
(A, G, C, or T/U)
DNA
Double Helix
“Rungs of ladder”
Nitrogen
Base (A,T,G or C)
“Legs of ladder”
Phosphate &
Sugar Backbone
DNA Nitrogen Bases
• PURINES
1. Adenine (A)
2. Guanine (G)
A or G
• PYRIMIDINES
3. Thymine (T)
4. Cytosine (C)
U or C
RNA Nitrogen Bases
• PURINES
1. Adenine (A)
2. Guanine (G)
A or G
• PYRIMIDINES
3. Uracil (U)
4. Cytosine (C)
U or C
DNA
• Adenine must pair with Thymine
• Guanine must pair with Cytosine
T
A
G
C
5
Hydrogen bonds
O
3
3
P
5
O
O
C
G
1
2
P
5
3
4
4
P
5
P
2
3
1
O
O
T
A
P
3
O
3
5
5
P
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DNA Structure Compared to RNA Structure
DNA
RNA
Sugar
Deoxyribose
Ribose
Bases
Adenine, guanine,
thymine, cytosine
Adenine, guanine,
uracil, cytosine
Strands
Double stranded
with base paring
Single stranded
Helix
Yes
No