Download Unit 3: Chemistry of Life

Unit 3: Chemistry of Life
Mr. Nagel
Meade High School
IB Syllabus Statements
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3.2.1
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3.2.2
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Explain how a DNA double helix is formed using complementary base pairing and hydrogen bonds.
3.3.5
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Outline how DNA nucleotides are linked together by covalent bonds into a single strand.
3.3.4
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State the names of the four bases in DNA.
3.3.3
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Outline DNA nucleotide structure in terms of sugar (deoxyribose), base and phosphate.
3.3.2
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Compare the use of carbohydrates and lipids in energy storage.
3.3.1
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State three functions of lipids.
3.2.7
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Outline the role of condensation and hydrolysis in the relationships between monosaccharides, disaccharides and
polysaccharides; between fatty acids, glycerol and triglycerides; and between amino acids and polypeptides.
3.2.6
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State one function of glucose, lactose and glycogen in animals, and of fructose, sucrose and cellulose in plants.
3.2.5
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List three examples each of monosaccharides, disaccharides and polysaccharides.
3.2.4
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Identify amino acids, glucose, ribose and fatty acids from diagrams showing their structure.
3.2.3
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Distinguish between organic and inorganic compounds.
Draw and label a simple diagram of the molecular structure of DNA.
http://click4biology.info/c4b/3/chem3.htm
Carbohydrates
• CnH2nOn (1:2:1 ratio)
• Structure
– Rings  Chains
– α-linkages and β-linkages
– Isomers (same formula, different arrangement)
• Glucose (cell energy), Galactose (milk), Fructose (fruit)
• All are isomers of C6H12O6
• Mono, Di, and Poly
– Di
• Lactose (Glucose + Galactose)
• Sucrose (Fructose + Glucose)
• Maltose (Glucose + Glucose)
– Poly
• Glycogen (Animal sugar storage chain)
– α -1,4 Glucose (more branching)
• Starch (Plant sugar storage chain)
– α -1,4 Glucose (less branching)
• Cellulose (Plant cell wall)
– β-1,4 Glucose
Carbohydrates
Lipids
• Non-polar Hydrocarbon chains
– Lots of C’s and H’s, few O’s
– Three functions
• Store energy, Cell membranes, Vitamins/Hormones
– Fats, waxes, sterols, fat-soluble vitamins
• Hydrophobic
• Monomer (most): Fatty Acid
– hydrophilic head (carboxyl end), hydrophobic tail (hydrocarbon)
>Saturated – means all Carbons have 2 hydrogen atoms bonded to it.
>Unsaturated – means that some Carbons have double bonds (less H atoms)
• Three types
Triglycerides
composed of three molecules of fatty acids and joined to one molecule of glycerol
Solid at room temp  fats; Liquid at room temp  oils
Waxes
composed of long fatty acid chain joined to a long alcohol chain
waterproofing (plant leaves)
Steroids
composed of four carbon rings
ex: hormones, nerve tissue, and plant poisons
Lipids
Amino Acids
• Peptide Bond – covalent bond between the
amino (NH2) group of one amino acid and the
carboxylic group (COOH) of another
>Dipeptide – two amino acids bonded together
>Polypeptide – 3+ amino acids bonded together
• Enzymes – proteins that act as catalysts in
intermediary metabolism that are essential for
functioning of cell
• Substrate – reactant in a chemical reaction that
is catalyzed by the enzyme
Amino
Acids
Protein Structure
• Primary
– Individual Amino Acid ‘Spelling’
• Secondary
– Local geography (H bonds)
• Alpha helices
• Beta pleated sheets
• Tertiary
– Large geography (protein shape)
• Hydrophobic regions
• Disulfide bridges
• Ionic bonds
• Quaternary
– Macrostructure (multiple units to make uber protein)
Nucleic Acids
• Monomer: Nucleotide
• Three components
• Phosphate group
• 5-carbon Sugar
• Pentose
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Ribose
Deoxyribose
• Nitrogenous Base
• Two Flavors
• DNA
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Genetic Information
• RNA
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Protein manufacturing
Organic molecules
• Carbon backbone
with one or more
additional elements
– Rings, branched, unbranched,
double bonds, triple bonds
• Monomers  Polymers
(macromolecules)
• Hydrolysis
• Condensation R(x)s
Gizmo!
• Time to explore how monomers are assembled
and disassembled
– Enroll in class
• We already did this the first week of school, but you may forget
your login or may have transferred/switched classes
– A2: FNRN6JKZTK
– B1: ZKWLDCNKSL
– Play around. There are THREE tabs to explore.
– Answer the assessment questions (you get one try!)
• Mini-Lab grade! (5 points)