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Chapter 3 The Chemical Basis of Life, II:Organic Molecules - Coggle…
Chapter 3
The Chemical Basis of Life, II:Organic Molecules
The carbon atom
4 electrons in outer shell
makes up to four bonds
usually single or double
bonds can be polar or non-polar
polar bonds are water soluble
C-O
C=O
non-polar bonds not very soluble
exp. Hydrocarbons
C-H
C-C
Polarity refers to physical properties like
melting points
boiling points
solubility
Organic and inorganic molecules
organic contain carbon
Fats
Nucleic acids
Sugars
Enzymes
Proteins
Hydrocarbon fuels
inorganic does not contain carbon
Acids
Bases
Salts
Metals
Functional groups
Groups of atoms with special chemical features
exhibits the same properties in all molecules in which it occurs
examples
-OH
-COOH
-CO
-NH2
Isomers
Two molecules with an identical molecular formula but different structures and characteristics
Types
Structural isomers
different bonding relationships
Stereoisomers
Cis-trans isomers
Enantiomers
spatial positioning differs
Organic Molecules
and Macromolecules
Formation
dehydration (condensation)
forming polymers from monomers
H2O is produced
catalyzed by enzymes
Hydrolysis
breaking down polymers to monomers
requires water
catalyzed by enzymes
Carbohydrates
Cn(H2O)n
Most C are linked to H or OH.
Monosaccharides
Simplest sugars
Most common are 5 or 6 carbons
Pentoses
Deoxyribose (C5H10O4)
Ribose (C5H10O5)
Hexose
Glucose (C6H12O6)
Glucose isomers
Structural isomers
Glucose and galactose
Stereoisomers
α- and β-glucose
D- and L-glucose
Disaccharides
two monosaccharides
sucrose
maltose
lactose
Glycosidic
bond
Polysaccharides
Many monosaccharides
Examples
Energy storage
starch
Moderately branched
glycogen
Highly branched
Structural
cellulose
Unbranched
chitin
glycosaminoglycans
Lipids
nonpolar
very insoluble in water
40% of the organic matter in the average human body
Fats (triglycerides)
Formed by bonding glycerol to 3 fatty acids
Joined by dehydration; broken dowm by hydrolysis
Fatty acids
Saturated
solid
Unsaturated
liquid
important for energy storage
structural
cushioning
insulation
Phospholipids
Formed from glycerol, two fatty acids and a phosphate group
amphipathic
Fatty acid tail: nonpolar / hydrophobic
Phosphate head: polar / hydrophilic
Steroids
Fout rings of carbon
insoluble in water
ex: Cholesterol
Tiny differences in structure can lead to profoundly different, specific biological properties
Estrogen vs. testosterone
Proteins
Amino acids
Building blocks
20 different amino acids
Common structure with variable sidechain that determines structure and function
Polypeptide formation
dehydration
hydrolysis
peptide bond
Primary structure
Amino acid sequence
encoded by genes
Secondary Structure
α helices and β pleated sheets
Random coiled regions
happens when protein folds
Five factors
Hydrogen bonds
Ionic bonds
Hydrophobic effects
Van der Waals forces
Disulfide bridges
Protein-protein interactions
Use first four factors
Tertiary structure
complex 3D shape
Quaternary structure
Made up of two or more polypeptides
Nucleic Acids
genetic information
Two classes
DNA
double helix
Thymine
Deoxyribose
RNA
single strand
Uracil
Ribose
Monomer is a nucleotide
phosphate group
five-carbon sugar
base
linked by sugar-phosphate backbone