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What is a Lipid?
- -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
What is lipid "saturation"?
- Refers to the degree of the way carbon atoms in a fatty acid are linked to hydrogen atoms
- 2 Types-saturated and unsaturated
What is the structure of an unsaturated fatty acid?
- 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.
What is the structure of a saturated fatty acid?
- The structure is linear and has no Double bonds
- This allows the fatty acids to be more compact within the structure.
What are the 3 types of important Lipids are found in cells?
Steroids, Fats and Phospholipids
Desribe the characteristics of Steriods.
- 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
Why is Cholesterol is an extremely important steroid in mammals?
they are integral compenents of mammalian cell membranes
What does the steroid hormone do?
It functions as a signaling molecules
Describe the characteristics of Fats.
- composed of 3 fatty acid monomers linked together via "a glycerol molecule"-aka Triglyceridessynthesized thru a series of dehydration reactions.
- -carboxylic acid groups of fatty acids+ hydroxyl groups of glycerol= Ester linkages(special covelant bonds)
What is the overall function of Fats in animals and plants?
They function as Storage molecules
Define the characteristics of Phospholipids
- 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.
What is the structure of Amphipathic molecules?
- 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
What are the functions of Carbohydrates?
- -Serve as building blocks in the synthesis of other molecules.
- -Indicate Cell Identity
- -Store Chemical energy
- -Provide cells w/fibrous structrual materials
What "Can't" Carbohydrates do?
They lack "the structural and chemcial complexity of molecules" that are able to catalyze chemcial reactions.
How do Carbohydrates function as Cell Identifiers?
- 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
What is a glycoprotein and what does it function as?
Glycoproteins are key identification badges that function in cell-cell recognition and cell-cell signalin
What is the function of glycolipids?
- Glycolipids help cells identify
- - subcellular spaces, form tissues
- -regulate the overall fluidity (flexibility) of their membranes
"Outside" cell locations
"internal" cell locations
How do Carbohydrates function as Energy Storagers?
Energy is locked into the covalent bonds of carbohydrates> allows carbohydrates to participate in exergonic chemical reactionsd=ATP
What are Exergonic chemical reactions?
- 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.
What form do Carbohydrates is stored in plants?
- 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
What form of Carbohydrates is stored in animals?
- Animals store sugars as Glycogen.
- -highly branched.
- -made of many Alpha-glucose joined by alpha-1, 4-glycosidic linkages. =forms distinct helical structures
How does branching occur in glycogen and starch?
- 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
How do Carbohydrates function as Structural Materials?
- 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
What are the 3 Structural Materials?
Cellulose, Chitin, and Peptidoglycan.
What is Cellulose?
- It is a polymer of Beta-gluecose monomers, linked by Beta-1, 4-glycosidic linkages.
- -Found in Plant cell walls.
What is Chitin?
- Its a polymer of N-acetylglucosamine monomers, linked by Beta-1, 4-glycosidic linkages.
- -found in Funal cell walls and insect/crustacean exoskeletons.
What is Pepitdoglycan?
- 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.
What are Carbohydrates?
- They're "Hydrated Hydrocarbons" composed of primarily carbon, hydrogen, & oxygen atoms.
- -repeating chains of hydrated carbons=monosaccharides (simple sugars). Which are building blocks of carbohydrates.
What are Monosaccharides?
- 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
What are the classifciatons for the Number of Carbon Atoms in a Monosaccharide?
- 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.
What are the different classifications of The location of the carbonyl group in Monosacchrides?
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.
What is the signifigance of the Spatial arrangement of Monosaccharide atoms?
- 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
Monosaccharides: Linear vs. Ring
- 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
What are Polysaccharides?
- They're polymeric carbohydrate.
- -formed thru Condensation reactions b/w the hydroxyl groups on seperate monosaccharides.
- -Condensation reaction=special covelant bonds called Glycosidic linkages.
What is a Glycosidic Linkage?
- 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.