Biological Macromolecules

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Biological Macromolecules
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FORMING MOLECULES

• Condensation Synthesis
• remove water
• new molecule (cooking!)

Hydrolysis - add water - break up a molecule
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FORMING MOLECULES
Condensation Synthesis/ Dehydration synthesis
Hydrolysis
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Stereoisomers
Stereoisomers/enantiomers Exactly the same atoms
arranged in same sequence, but they differ in
spatial orientation. D-isomers
right-handed. L-isomers left-handed. Enzymes
are specific we can utilize only certain
stereoisomers! only L-amino acids and D-sugars.
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• Biological Macromolecules

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Biological macromolecules

• Monomer one subunit
• Polymer large molecule, made of many monomers

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Biological macromolecules

• Monomer Polymer
• amino acids (20 types) ---gt Proteins
• sugars ---gt Carbohydrates
• nucleotides (4 types) ---gt Nucleic Acids
• fatty acids ---gt Lipids

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• Proteins

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Structural Proteins
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Proteins

• Proteins are amino acid polymers.
• Many roles!!!
• Enzymes
• Hormones
• Structure
• Signaling
• Transport
• DO-ERS

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Amino Acids

• Small molecules 20 kinds
• 1 amino group
• 1 carboxyl group
• 1 "R" group
• Joined by peptide bonds to form polypeptide
• Different sequence makes different protein.

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Generic AminoAcid 20 Different R Groups
Carboxylic AcidGroup
AmineGroup    
R
R Group
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Glutamic Acid
AmineGroup  
Carboxylic Acid     Group
Glutamic AcidR Group
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Arginine
Carboxylic Acid     Group
AmineGroup  
Arginine R     Group
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Phenylalanine
Carboxylic Acid     Group
AmineGroup  
PhenylalanineR Group
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Leucine
Leucine R     Group
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Cysteine
Cysteine R     Group
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Proteins

• Protein structure, known as configuration, is
  intrinsic to its function.
• - shape
• - chemistry (possible bonds)

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Illustration ofProtein Structure
Primary
Tertiary
Quaternary
Secondary
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Levels of Protein Structure

• Primary The sequence, polypeptide chain
• Secondary Coiling of the chain alpha helix,
  beta sheets
• Tertiary Coiling of the coil (disulfide bonds)
• Quaternary Two or more chains together

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Proteins
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Proteins

• Denaturation heat, pH unravels protein down to
  primary structure
• Chaperonins special proteins, they help with
  initial folding and also protect other proteins
  during heat shock.

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Proteins

• Protein chains have directionality
• N-terminus (amino group) to C-terminus (carboxyl
  end)
• We can sequence protein chains, but we still
  cant predict the way they will fold up!
• Structural biology uses x-ray crystallography
  and NMR spectroscopy to figure out the 3-D
  structure of proteins

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Proteins

• Peptide 20 aa
• Polypeptide 100 or less aa
• Protein over 100 aa

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Proteins

• Glycoproteins protein, plus CH
• Lipoproteins protein, plus lipids

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• CARBOHYDRATES

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CARBOHYDRATES

• ose
• Soluble in water
• Taste sweet
• MONOSACCHARIDE
• Mono- means one
• Often CH2O
• Simple sugars e.g. GLUCOSE
• Often pentoses, hexoses (5, 6 carbons)

Deoxyribose
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CARBOHYDRATES

• DISACCHARIDES 2 sugars
• Made through?!

Sucrose Water
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CARBOHYDRATES

• Monosaccharides glucose, fructose, galactose
• Disaccharides sucrose (glucose fructose)
• lactose (glucose galactose)
• maltose (glucose glucose)

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CARBOHYDRATES

• POLYSACCHARIDES more than 2!
• Important in metabolism.
• Sometimes used for cell I.D.
• Store energy.

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CARBOHYDRATES

• Polysaccharides
• starch (amylose), cellulose, chitin, glycogen are
  all polymers of glucose.

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Plant Starch Amylose
Spiral polymer of glucose
Glucose
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Cellulose
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Cellulose
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Chitin

• Arthropods exoskeletons, fungal cell walls
• Like cellulose, but with nitrogen
• Strong, very resistant to digestion

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Glycogen branched polymer
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CARBOHYDRATES

• Humans eat starch, break it down -gt glucose,
  synthesize -gt glycogen (in liver)
• Bacteria in termites, cows stomachs, fungi
  digest cellulose. Why cant we?! We call it
  fiber.

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• Nucleic Acids

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Nucleic Acids

• Nucleotides monomers
• NUCLEIC ACIDS nucleotide polymers
• DNA Genes, blueprint
• RNA Messenger, to make proteins.

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Nucleotides

• Also
• energy carrier ATP (monomer)
• chemical messenger cAMP

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NucleotideStructure
Phosphate Group
NitrogenousBase
Varies DNA ATCG RNA AUCG
Sugar
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Nucleic Acids

• Nucleotide base, sugar, phosphate
• Nucleoside base, sugar (no phosphate)
• Bases
• Pyrimidine cytosine (C ), thymine (T), uracil
  (U)
• Purine adenine (A), guanine (G)

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Nucleic Acids

• Sugar pentose
• Ribose in RNA (ribonucleic acid)
• Deoxyribose in DNA (deoxyribonucleic acid)
• Built in directionality 3 end (hydroxyl) vs.
  5 end (phosphate) of sugar

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Nucleic Acids

• Nucleotides can be joined together into a chain
  (polymer!).

Result is DNA, RNA Sugar-phosphate
backbone. Bases
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DNA
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Nucleic Acids
DNA double helix of antiparallel (3 to 5 and
viceversa), complementary strands
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Nucleic Acids

• DNA
• Complementary base pairs
• A with T
• C with G

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Nucleic Acids

• RNA
• Complementary base pairs
• A with U
• C with G

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DNA vs. RNA
DNA deoxyribose sugar, phosphate, ATCG RNA
ribose sugar, phosphate, AUCG DNA double
stranded RNA single stranded
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• Lipids

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Lipids

• i.e. FATS
• Slippery-oilies
• Nonpolar insoluble in water
• Mostly C and H

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Lipids

• Very heterogeneous group
• Some are polymers of FATTY ACIDS
• Fatty-acid types Oils waxes
• Nonfatty-acid types steroids

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Fatty Acids

• Fatty acid (FA) Hydrocarbon (CH) chain with a
  carboxyl (COOH) at the end
• Many fats triglycerides (aka triacylglycerol)
• 3 FA monomers glycerol
• Triglycerides are in beef, vegetable oils,
  butter, etc.

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Fats
Unsaturated - One or more CC double bonds -
Usually vegetable fats -
Liquid at room temperature (RT)
Saturated - No CC double bonds - Usually
animal fats - Solid at RT
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UNSATURATED FAT
FATS
Vegetable oils Better for you!!!
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Trans fats
Partially hydrogenated oils, aka trans fats
- Created by hydrogenating unsaturated fats
- Solid at RT
- e.g margarine, crisco
- found in almost all processed foods
soup, crackers, cookies
- belly spread heart attacks
BAD FOR YOU!!!
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TriglycerideFormation
Triglyceride
Glycerol
RemoveTheseWaters
Add 3FattyAcids
3 Waters
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Lipids

• Phospholipids - mostly in membranes
• Soap-like
• In an aqueous environment they self-assemble into
  micelles, liposomes, bilayers

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Phospholipids
PolarHead
Glycerol
Fatty Acid Tails
Hydrophobic (non polar!)
Hydrophilic (polar!)
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Phospholipids (micelle)
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Steroids

• Some hormones
• Cholesterol
• Natural substance
• Hormone precursor
• Found in membranes
• Essential for life!!!

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Steroids
Cholesterol