Download Biochemistry

Proteins
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Made of Carbon, Hydrogen,
Oxygen, Nitrogen (and
sometimes sulfur)
Arranged from only 20 amino
acids!!! (like the alphabet)
Amino Acids
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Made up of 4 parts
Part 1 = Hydrogen atom
Part 2 = Amino group (NH2)
Part 3 = Acid group (COOH)
Part 4 = R group (side chains that
differ from amino acid to amino acid)
http://hyperphysics.phyastr.gsu.edu/HBASE/organic/ami
nostruct.html
Protein Structure
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1 amino acid linked to another
by a peptide bond (see drawing
on board)
Does this look familiar?????
DEHYDRATION SYNTHESIS
Protein Structure
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Many amino acids linked
together are a polypeptide
chain
Chain folds up on itself to form
a giant ball (like a mess of yarn)
which forms the protein
There are four levels of protein
structure
Protein Structure
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Primary Level
• Polypeptide chain- like fruit frenzy
on a string
Protein Structure
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Secondary Level
• Chain coils around (like a spring)
• Called the alpha helix
Protein Structure
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Tertiary Level
• Coil becomes folded up
Protein Structure
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Quaternary Level
• Multiple chains join together
PROTEINS
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Most diverse
group of
biological
molecules
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Enzymes
Structural
Transport
Nutritious
Regulatory
Defense
Function
depends on
structure
Enzymes- a special kind of
protein
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Special proteins - increase
chemical rxn rates – called
catalysts
Most biological rxns can’t take
place without them
How Enzymes Work
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Energy needed to start a
reaction
Called ACTIVATION ENERGY
Enzymes lower this
How Enzymes Work
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Enzymes help rxns occur at
normal cell temps
Weaken chemical bonds
Heat does too- but heat not
good for cells
How Enzymes work
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Enzymes are specific- each
helps only 1 reaction occur
What’s involved?
Substrate- what the enzyme
acts on
Active site- where the substrate
fits perfectly in to the enzyme
Like pieces of a puzzle
An enzyme at work