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Chapter 3 (Chemical bases of life ) - Coggle Diagram
Chapter 3 (Chemical bases of life )
Organic molecules
They contain carbon
Carbon has 4 electrons on its outer shell. (Needs 4 more electrons to fill the shell)
It can make up to 4 bonds (single or double)(polar or nonpolar)
They are abundant in living oraganisms
Macromoleculeis a large, complex organic molecule.
Functional groups
Groups of atoms with special chemical features that are functionally important.
Each type of functional group exhibits the same properties in all molecules in which it occurs.
Formation of macromolecules and organic molecules
Condensation or dehydration
Link’s monomers to form polymers
A molecule of water is removed each time a new monomer is added, thus a dehydration reaction
The process repeats to form long polymers
A polymer can consist of thousands of polymers.
Dehydration is catalyzed by enzymes.
Hydrolysis
Polymers broken down into monomers
A molecule of water is added back each time a monomer is released.
The process repeats to break down long polymer
Hydrolysis is catalyzed by enzymes
Isomers
Two molecules with an identical molecular formula but different structures and characteristics.
Structural isomers
Contain the same atoms but in different bonding relationships.
Steroisomers
Cis-transvisomers
Positioning around double bound
Enantiomers
Mirror image molecules
Types of organic molecules
Carbohydrates
Composed of C,H and O atoms.
(Cn(H2O)n)
most of the carbon atoms in carbohydrate are linked to a hydrogen atom and a hydroxyl group.
Monosaccharides
-Simplest sugars.
-most common are 5 or 6 carbons.
-pentoses(5C)
Ribose(C5H10O4)
deoxyribose(C5H10O4)
-Hexose
glucose (C6H12O4)
Ways to depict structure
Ring
Linear
Diasaccharides
-Composed of 2 monosaccharides.
-joined by dehydration (glycosidic bond)
-broken down by hydrolysis.
-EXAMPLE:
1)sucrose 2)maltose
3)lactose
Polysaccharides
-Many monosaccharides linked together to form long polymers.
-examples:
1)energy storage: starch(plant), glycogen
(animals).
2)structural: cellulose(plant)
chitin(insects).
Starch is moderately branched.
Glycogen is highly branched
Cellulose is unbranched
Lipids
-Composed of C,H and some O. -lipids are nonpolar and non soluble in water.
Includes
Fats
-Also know as triglycerides.
-formed by glycerol and 3 fatty acids.
-joined by dehydration;
broken apart by hydrolysis
Fatty acids
Saturated
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Unsaturated
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Fats are important for:
1) energy storage: the hydrolysis of triglycerides releases the fatty acids from the glycerol. And these products can be matablized to provide energy.
2) structural: providing cushions that support organs and insulation under the skin that helps.
Phospholipds
-formed by one glycerol and two fatty acids and a phosphate group.
-phospholipids are amphipathic molecules.
phosphate head: polar.
fatty acid tail: nonpolar.
Sterioids
-Four interconnected rings of carbon atoms form the skeleton of all steroids.
-usually insoluble in water.
-EXAMPLE: cholesterol.
Tiny differences in structure can lead to profoundly different, specific biological properties.(estrogen vs testosterone)
Waxes
Proteins
Composed of C,H,O,N and small amount of sulfur.
-Building blocks are (amino acids)-20 different amino acids -common structure with variable side chain that determines structure and function.
Amino acid structure:
1)amino group.
2)carboxyl group. 3)side chain
Polypeptide formation.
-amino acids joined by dehydration reaction.
(carboxy+amino forms peptide bond)
-Polymers of Amino acids know as polypeptides.
-proteins may be formed from 1 or several polypeptides.
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Primary structure
The linear sequence of amino acids is the primary structure.
Encoded directly by genes
Secondary structure
Certain sequence of amino acids form hydrogen bonds that cause the region to fold into spiral (alpha helix) or sheet (beta pleated sheet)
Chemical and physical interactions cause protein folding.
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-Random coiled regions -not a alpha or beta -specific shape and important to function
Tertiary structure
Secondary structures and random coiled regions fold into a 3-dimensional shape
-Folding gives protein complex 3D shape.-this is the final level of a structure for a single polypeptide chain
Quaternary structure
Two or more polypeptides may bond to each other to form structure protein.
-Made up of two or more polypeptides
-individual polypeptide chains are protein subunits.
-proteins can be formed from several copies of the same polypeptide.
-or may be multimetic (composed from different polypeptides)
Five factors that promote protein folding and stability
Hydrogen bonds
Ionic bonds and other polar interactions.
Hydrophobic effects
Van der waals forces
Disulfied bridge
Nucleic acids
Responsible for the storage, expression and transmission of genetic information.
2 CLASSES:
Deoxyribonucleic acid(DNA)
Stores genetic information encoded in the sequence of nucleotide monomers.
-monomer is nucleotide.
-made up of phosphate group , a five carbon sugar (either ribose or deoxyribose) and a single or double ring of carbon and nitrogen atoms known as base.
-nucleotides are linked into polymer by a sugar phosphate backbone.
Ribonucleic acid(RNA)
Decodes DNA into instructions for linking together a specific sequence of amino acids to form polypeptide chains