10/20/14 Objective: What are the properties of Lipids? Take out your HW Chapter 5: The Molecules of...
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Transcript of 10/20/14 Objective: What are the properties of Lipids? Take out your HW Chapter 5: The Molecules of...
10/20/14
Objective: What are the properties of Lipids?
Take out your HW
Chapter 5: The Molecules of Life
Do Now: What can happen to sugar if not used for energy?
Lipids
• lipids: class of compounds that are hydrophobic (water-fearing) and nonpolar– Made of glycerol and
fatty acid– Part of cell membrane– store energy
Fatsfats(triglyceride):) made of glycerol attached to 3 fatty
acids(long hydrocarbon chains)– Solid or liquid– cushion organs and provide body with insulation
• saturated fats: all fatty acid chains contain the maximum possible number of hydrogen atoms– All single bonds– Animal fats (solid at room temp)
• unsaturated: less than max. number of H atoms
- Double- bonds– Most plant and fish oils
(liquid at room temp)
Steroids
steroids: carbon skeleton forms 4 fused rings
• Examples: Cholesterol, Sex hormones
Cholesterol
• cholesterol: essential molecule found in cell membranes– Help maintain membrane
structure
Phospholipids
• Major part of cell membrane
5.4 Proteins
• protein: a polymer constructed from monomers called amino acids.– Ex: Enzymes, hormones,
cell receptors, immune defense
Protein Structure
• amino acid: monomer of proteins
• Polypeptide: chain of amino acids that make up a protein– Made by dehydration synthesis
Shape• Polypeptides fold into
specific shapes • Shape of protein
determines how it will function
Enzymes
• enzymes: proteins that act as organic catalysts– Lowers activation energy
• pH and temp can affect function
How Enzymes Work
• substrate - a specific reactant acted upon by an enzyme
• active site - where enzymes binds to substrate
Substrates are the reactants. Lactose is the substrate, lactase is the enzyme.
Denaturation
• Denaturation: A change in pH, temperature, causes the protein to unravel and lose shape, therefore function
Enzyme Function
Describe what is occurring in the picture:
Enzyme Function
Nucleic Acids• DNA: dexoyribose
nucleic acid• RNA: ribose nucleic
acid• Nucleotides:
monomers of DNA/RNA