Chapter 5 Macromolecules Building blocks of life.
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Transcript of Chapter 5 Macromolecules Building blocks of life.
Chapter 5 Macromolecules
Building blocks of life
Macromolecule Composition
• Monomers• Polymer• Covalent linkages• Dehydration reactions• Hydrolysis reactions
Categories of Macromolecules
• Carbohydrates• Lipids• Proteins• Nucleic acids
Carbohydrates
• Sugars• Sugar polymers• Glycosidic linkage
– Covalent
• Categories– Monosaccharide– Disaccharide– Polysaccharide
Monosaccharides
• Single sugar molecule• Can function as
monomer• Ring form• Aldoses• Ketoses
Ring Forms of Sugars
Disaccharides
• Two sugar molecules• Dehydration reaction• Glycosidic bond• Sucrose• Lactose• Maltose
Derivatives of Carbohydrates Sweeteners
Polysaccharides
• Many sugar molecules
• Glycosidic linkage• Starch
– Alpha
• Cellulose– Beta– Structural
polysaccharide
• Chitin
Lipids
• Fats and oils• Hydrocarbon tails or
rings• Very non polar• No true monomer• Most composed of
glycerol and fatty acids
• Linkage-ester
Subcategories of Lipids
• Neutral lipids
• Phospholipids
• Steroids
• Waxes
Neutral Lipids
• Glycerol backbone• 1, 2, or 3 fatty acids• Triglyceride• Ester linkage• Adipose storage• Plant oils• Saturated- animal source• Unsaturated- plant source
Phospholipids
• Glycerol backbone• 2 fatty acid tails• Phosphate head• Amphipathic• Polar head• Non-polar tails• Components of all
biological membranes
Phospholipids (cont.)
• Bilayer• Micelle• Liposome• Emulsifying agent
Steroids
• Common ring structure
• Very planar• Sex hormones• Cholesterol
– Stabilize membranes
Waxes
• Very hydrophobic• Long chain alcohol
esterified to very long chain fatty acid
• Waterproofing• Ducks
Proteins
• Polymers of amino acids
• Amino acid as monomer
• Peptide bonds• Very diverse group of
macromolecules
Amino Acids
Amino Acids
Essential Amino Acids
• Animal sources
• Plant sources– Complementation groups
Protein functions
• Enzymatic proteins• Structural proteins• Storage proteins• Transport proteins• Hormonal proteins• Receptor proteins• Contractile and motor proteins• Defensive proteins
Enzymatic Proteins
• Catalyst• Rate of reactions• Energy changes• “Match maker”• Shape• Active site• Activation energy
Structural Proteins
• Confer shape • Capsid proteins• Cytoskeletal proteins
Storage Proteins
• Albumin• Amino acid storage• Egg white
Transport Proteins
Receptor protein
• Hormones• Viruses• Cell communication
Contractile Proteins
Defense Proteins
• Antibodies
Protein Structure
• Four levels of organization
• Primary
• Secondary
• Tertiary
• Quaternary
• See pages 82-83 in text
Primary and Secondary
Tertiary and Quaternary
Denaturation
• Unfolding• Break H bonds• Heat• pH changes
Protein Folding
• Hydrophilic interactions
• H bonding • S-S bridges• Chaparonins
Amino Acid Sequence
• Ultimately determined by the DNA base sequence
• Dictates final folding and shape
Nucleic Acids
• Polymers of nucleotides
• DNA• RNA
Nucleotides
• 5 carbon sugar– Ribose– Deoxyribose
• Nitrogenous base– Adenine– Guanine– Cytosine– Thymine– Uracil
• Phosphate- 1, 2, or 3
Nitrogenous base
• Letters in genetic code
• Purines– Adenine– Guanine
• Pyrimidines– Thymine– Cytosine– Uracil
Structure of Nucleic acids
• Sugar/ Phosphate back bone- similar to paper
• N base as “letter” written on the backbone
• Anti-parallel alignment if double stranded
Functions of Nucleic Acids
• Information molecules• DNA
– Hereditary information– Recipe book– Each recipe is one
gene– Each gene encodes
one protein
• RNA– Working copy of one
gene or recipe
DNA
• Hereditary function– DNA replication
• Master recipe book– Transcription
RNA
• Working copy of a gene
• Transcription– Make RNA
• Translation– Make protein