Transcript BiologyReferences_files/Biochemistry updated 2012

Biochemistry
http://www.brainpop.com/science/matterandchemistry/bodychemistry/
Chemistry of Carbon
• Carbon can form
covalent bonds with
up to 4 other atoms
• Hydrocarbonscompounds made up
of only carbon and
hydrogen
Giant Molecules from Small Building
Blocks
• Macromolecules:
Carbohydrates
Fats
Proteins
Nucleic Acids
• Structure: Polymers- large molecules
made by stringing together many small
molecules called monomers
Basic building blocks
a long train of box cars ?
Monomer
single building block unit
Dimer
Polymer
>3 generally 100-1,000 monomers = Polymer
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Carbohydrates
C, H, O
2:1 ratio of H to O
Monosaccharide
–C6H12O6 = glucose, fructose
Disaccharide = 2 mono’s: C12H22O11
–Sucrose, lactose
Polysaccharide = 100’s to 1,000’s
–Starch, cellulose, glycogen, chitin
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Polysaccharides: are the most abundant organic
compounds in the biosphere.
 Cellulose
– most common polysaccharide
– (estimate - over 1 trillion tons made
–
by plants/year)
 Starch (in plants)
– is stored in plant cell vacuoles.
 Glycogen (in animals) – highly branched starch
– glycogen. (In mammals, glycogen stored in liver and muscles provides a quick source of energy.
– Excess glucose ? taken up from the blood - stored where ?
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Monomer
Polymer
Dimer
Dehydration Synthesis: Process in which cells link monomers together to form polymersResults in loss of water
H
H
OH
H2O
H
Hydrolysis: Digestion of macromolecules through the addition of water
H2O
H
OH
Check Point:
1. Draw the structural formula for C2H4. Remember that each carbon has
4 bonds; each hydrogen has 1.
2.When two molecules of glucose (C6H12O6) are joined together in a
dehydration synthesis reaction, what are the formulas of the two
products?
Carbohydrates
Sugars
Monosaccharides: Simple sugars (monomers)
Molecular formula: Multiple of CH2O
Ex. Glucose and Fructose - C6H12O6
Isomers
Isomers: Same
molecular formula,
different structure
and therefore
different properties
Disaccharides: double sugar
High Fructose Corn Syrup: Corn syrup producers
developed a way to convert half of the glucose in corn
syrup to fructose (sweeter)
Table Sugar
Polysaccharides: Complex carbohydrates- long
chains of sugar units
Starch: Form of stored sugars in plant roots and
other plant organs
**Potatoes, wheat, rice, and corn are high in starch
Glycogen: Form of stored sugars in
animals, found in liver and muscle cells.
Cellulose: Structural component of plants,
found in the cell walls. Unable to be digested
by animals. (Fiber)
bioweb.wku.edu
Lipids (C, H, O)
Nonpolar – don’t dissolve in water
–hydrophobic- water fearing.
High proportion of C-H bonds
very little O (oxygen)
Some lipids may contain P and N
Not polymers
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Lipids
Glycerol
Fats, Oils, and Waxes
Stores energy (2x as much as carbs)
Stored in adipose cells
Fatty acid
Fatty acid
Fatty acid
}
Triglyceride
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Lipids
• Fats, Oils, and Waxes
• Stores energy (2x as much as carbs)
• Stored in adipose cells
Fat = Triglyceride
Composed of 1 glycerol and 3
fatty acid molecules joined by
dehydration synthesis
Glycerol
3 Fatty Acid Chains
Saturated v. Unsaturated Fats
•
•
Saturated: When all 3 fatty acid chains are
bonded to the maximum number of
hydrogens (No Double Bonds)
Unsaturated: When at least one fatty acid
chain has less then the maximum number of
hydrogens (At least one double bond)
Monounsaturated Fat Molecule
•
•
Steroids
Anabolic Steroids: synthetic variants
of testosterone
Hydrophobic
Cholesterol:
Present in cell
membrane and is
base molecule for
other steroids in the
body such as
testosterone and
estrogen
Cholesterol
Used to build muscle quickly and
increase performance
Risks: - Increase cholesterol
- Infertility
http://www.muscleenhancers.com/s
teroids/
Proteins
•
Types of Proteins:
•
•
•
•
•
•
•
Structural (hair, webs)
Storage (seeds)
Contractile (muscles)
Transport (hemoglobin)
Defensive (antibodies)
Signal
Enzymes (lactase)
Monomers = Amino Acids
http://www.aloeveraibs.com/aloe-vera-vitamins
*** Each “R” group is unique and
determines the chemical properties
of the amino acid
20 different amino acids!
http://universe-review.ca/F11-monocell.htm
•
Protein
Polymers
A Polypeptide is formed when dehydration
synthesis results in peptide bonds between
many amino acids
How do we make all of the tens of thousand
different polypeptides in our bodies from only 20
different amino acids?
Functions of Proteins
Enzymes: regulate the rate of chemical reactions in
cells.
– eg: Catalysts - speed up or slow down
Structural Proteins –
– Viruses - outer coat,
– keratin (hair, nails, hoofs, horns)
– Collagen -extra cellular matrix (ex. tendons, cartilage)
Hormones- (signaling) Oxytocin, Insulin, Vasopressin
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Functions of Proteins
• Contractile proteins – Actin, Myosin
• Storage Proteins – Casein (nutrient storage in milk), Ferritin (iron
storage in egg yolk and spleen)
• Transport Proteins – Hemoglobin, serum albumin (carries fatty acids
in blood)
• Immunological Proteins – Gamma globulins (circulating antibodies)
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Protein continued
Shape important
– “Hydrogen bonds”-help dictate shape
– side groups (R) interact along the polypeptide chain
• Causing:
–coil = spiral staircase, phone cord
–Folding = Pleated sheet
–combo – The shape: coil, stretched out, or folded
• Determines how a protein will act…(function)
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Primary Structure: The amino acid sequence of a
protein (Usually at least 100 amino acids long)
nature.com
Campbell
isbbio2.wikispaces.com
Secondary Structure: Hydrogen Bonds between amino
acids groups lead to patterns. Patterns are either alpha
helix or beta pleated sheets
Tertiary Structure: The overall 3D shape of the protein
www-3.unipv.it
Quarternary Structure: When a protein consists of
more than one polypeptide chain bonding with one
another
Ex: Hemoglobin
yellowtang.org
Campbell
What determines protein
structure?
• The amino acids sequence determines
the shape and therefore the function of
each protein.
• The shape of a protein allows it to carry
on it’s specific function. If it loses it’s
shape it will not work correctly.
• Unfavorable pH and temperature can
cause denaturation (unfolding) of a
protein and cause it to cease
functioning normally until pH or
temperature returns to normal.
ENZYMES
(Proteins)
• Metabolism: All of the chemical
reactions that occur in an organism
• ENZYMES: Specialized PROTEINS
that allow reactions to occur
• Enzymes speed up chemical
reactions
Activation Energy: Energy needed to
activate reactants and trigger a
chemical reaction
For a chemical reaction to
occur the bonds in the
reactants must be broken
which requires the
molecules to absorb
energy.
Enzymes reduce the amount
of activation energy required
to break the bonds in the
reactant molecules
Enzymes bind to the
reactants putting it under
stress, making it easier to
break their bonds
Induced Fit
* Enzymes can also be referred to
as catalysts
Each enzyme is specific as to which reactions
it catalyzes
Enzymes are proteins, and just like other
proteins they need to be the correct shape to
perform their function correctly.
• Substrate: The reactant molecule that
interacts with the protein
• Active Site: The area of the enzyme
that interacts with the substrate. The
shape and chemistry of it allows it to
interact with the substrate.
• Induced fit:
When the substrate slips
into the active site the active site
changes its shape slightly to allow a
better fit.
When the product is released the enzyme is free to
work again. (Catalysts are not used up in reaction!)
Enzyme Inhibitors
• Inhibit metabolic reactions by binding to
an enzyme and disrupting its function
• 2 types
1. Bind to and plug up the active site so substrate
can not access the active site
2. Bind to some place other than active site,
changing the shape of the enzyme making active
site no longer the correct shape to bind to the
substrate
Feedback Regulation: If metabolism
produces more of a certain product than is
needed the product may inhibit the enzyme
required for its own production
**Saves Resources
Nucleic Acids
Information storing molecules that hold instructions for
protein building
DNA and RNA
(Genetic Material
Nucleic Acids are polymers of monomers called
nucleotides
Nucleotides: Made up of 3 parts
1. 5 Carbon Sugar (Deoxyribose or Ribose)
2. Phosphate Group
3. Nitrogenous Base
- (Adenine, Thymine, Guanine, Cytosine, Uracil
msu.edu
biologyjunction.com
academic.brooklyn.cuny.edu