Biology181

• -carbon conatining biological molecule.
• -composed of building blocks called fatty acids
• -non polar & hydrophobic
• -contains mostly carbon & hydrogen atoms
• -has even #of carbon atoms
• -sythesized by joining 2carbon acetyl groups

• Refers to the degree of the way carbon atoms in a fatty acid are linked to hydrogen atoms
• 2 Types-saturated and unsaturated

• They possess 1+ double covalent bonds between two or more carbon atoms.
• D-bonds produce "kinks"> that prevent rotation and limit the flexibility of the hydrocarbon chain.

• The structure is linear and has no Double bonds
• This allows the fatty acids to be more compact within the structure.

Steroids, Fats and Phospholipids

• Unique family of lipids.
• -distinguished by its 4-ring structure.
• -synthesized by cyclizing a special triterpenoid hydrocarbon known as squalene.
• exs. Hormone steroid and cholesterol
• -signaling

they are integral compenents of mammalian cell membranes

It functions as a signaling molecules

• composed of 3 fatty acid monomers linked together via "a glycerol molecule"-aka Triglycerides
• synthesized thru a series of dehydration reactions.
• -carboxylic acid groups of fatty acids+ hydroxyl groups of glycerol= Ester linkages(special covelant bonds)

They function as Storage molecules

• Consist of a glycerol that is linked to a phosphate group (PO43-) &either 2chains of isoprene or 2fatty acid
• -Form Membranes!
• -synthesized same way as fats
• -Theyre Amphipathic molecules: conatin both hydrophobic and hydrophilic regions.

• They contain both a hydrophilic and hydrophobic region.
• - “head” region contains polar covalent bonds and atoms that carry charges.
• -“tail” region corresponds to the nonpolar hydrocarbon chains of the fatty acids.
• *when placed in a solution. The heads interact w/water wher the tails do not>results in membranes

• -Serve as building blocks in the synthesis of other molecules.
• -Indicate Cell Identity
• -Store Chemical energy
• -Provide cells w/fibrous structrual materials

They lack "the structural and chemcial complexity of molecules" that are able to catalyze chemcial reactions.

• Although "polysaccharides" are unable to store info, they do display info on the outer surfaces of cells.
• -presented in 2forms: glycoproteins and glycolipids.
• Which are sugars that have been joined to proteins and lipids, by strong covalent bonds

Glycoproteins are key identification badges that function in cell-cell recognition and cell-cell signalin

• Glycolipids help cells identify
• - subcellular spaces, form tissues
• -regulate the overall fluidity (flexibility) of their membranes

"Outside" cell locations

"internal" cell locations

Energy is locked into the covalent bonds of carbohydrates> allows carbohydrates to participate in exergonic chemical reactionsd=ATP

• It is a "energy-releasing" chemical reaction that yeilds ATP.
• (CH2O)n + O2 + ADP + Pi  CO2 + H2O + ATP
• The energy cycle is completed when organisms use ATP to drive endergonic (energy-requiring) reactions and perform cell work.

• Plants store carbohydrates as Starch.
• -can be unbranched (amylose) or branched (amylopectin)
• - made by many Alpha-glucose joined by alpha-1, 4-glycosidic linkages. =forms distinct helical structures

• Animals store sugars as Glycogen.
• -highly branched.
• -made of many Alpha-glucose joined by alpha-1, 4-glycosidic linkages. =forms distinct helical structures

• Occurs when glycosidic linkages fomr b/w carbon-1 of a glucose monomer on one strand & carbon-6 of a glucose monomer of another strand.
• -The enzyme "amylase" &phosphorylase catalyze the hydrolysis of alpha-glycosidic linkages in glycogen& starch> released subunits can b used4ATP productn

• Structural carbohydrates possess Beta-1. 4-glycosidic linkages.
• -difficult to hydrolyze-very few enzymes have actives sites that accomadate their Geometry or have Reactive groups necessary.
• -They form Long Strands w/bonds b/w adjacent strands. >orgnaized into fibers or layered in sheets.=yeilds cell's&organisms great strength& elasticity

Cellulose, Chitin, and Peptidoglycan.

• It is a polymer of Beta-gluecose monomers, linked by Beta-1, 4-glycosidic linkages.
• -Found in Plant cell walls.

• Its a polymer of N-acetylglucosamine monomers, linked by Beta-1, 4-glycosidic linkages.
• -found in Funal cell walls and insect/crustacean exoskeletons.

Structural Material.

• Its made up of 2types of monosaccharides, linked by Beta-1, 4-glycosidic linkages.
• -Each monomer is Cross-linked to a chain of Amino Acids, and peptide bonds link the Amino acid chains of adjacent strands.
• -It is a component of bacterial cell walls.

• They're "Hydrated Hydrocarbons" composed of primarily carbon, hydrogen, & oxygen atoms.
• (CH2O)n
• -repeating chains of hydrated carbons=monosaccharides (simple sugars). Which are building blocks of carbohydrates.

• The structures of Simple sugars differ in several key ways-helps define sugar building blocks.
• -# of carbon atoms
• -Location of carbonyl group
• -Spatial arrangement of their atoms

• 1. Triose sugars-3 carbon atoms
• 2. Pentose sugars-5 carbon atoms
• 3. Hexose sugars-6 carbon atoms

Monosaccharides are the building blocks of carbohydrates.

1. Aldose sugars-have a carbonyl group at the end of the monsaccharide. = a highly reactive aldehyde form.

2. Ketose sugars-have a carbonyl group in the middle of the monosaccharid= forms a reactive ketone.

• Grouping of atoms and defines type of sugar.
• 1. Most of the carbon atoms in simple sugars are chiral centers – the same groups of atoms can be linked to these carbons in different orientations.
• 2.The arrangement of the hydroxyl groups at each chiral carbon atom defines the type of simple sugar

• Glucose (&many other hexoses) form 6-membered rings called "hemiacetals"
• -through being dissolved in h2o at pH7 or in solid form.
• -The Cyclization process produces 2diff. forms (anomers) of glucose

• They're polymeric carbohydrate.
• -formed thru Condensation reactions b/w the hydroxyl groups on seperate monosaccharides.
• -Condensation reaction=special covelant bonds called Glycosidic linkages.

• Occurs thru condensation reaction b/w the 2hydroxyl groups on seperate monosaccharides.
• -The monomers (monosacchrides) joined by glycosidic linkages can be identical or diff.
• -The glycosidic linkages can form b/w ANY 2hydroxyl groups.>location&geometry of these bonds varies Widely.