PHSL 410B Lecture 6: Exam 3 Study Guide
Exam 3 Study Guide
Lipids
▪ Water insoluble molecules that function in:
o Structural components
o Energy storage
o Vitamins
o Barriers
o Chemical signals
Fatty acid
▪ Keeps the OH until pka: 4.5-5
Carbohydrates: hydrates of carbon; empirical formula is (CH2O) n
▪ Monosaccharides: single (CH2O) n
▪ Oligosaccharides: 2-20 (CH2O) n
▪ Polysaccharides: + 20 (CH2O) n
▪ Homoglycans: polysaccharides with the same sugar
▪ Heteroglycans: polysaccharides with different sugars
▪ 6 Functions of carbohydrates:
o Energy for cell, energy storage, structural elements for plants and animals, metabolic intermediates,
framework for nucleic acids/nucleotides, modification groups for proteins and lipids.
▪ Carbohydrates can be aldoses and ketoses
o Configuration: breaking carbon bonds (these are fisher projections)
▪ Chiral carbons pass through a plane polarized light in which they will be optically active. Then
they can be L configuration or D configuration, called a stereoisomer.
▪ D in carbs is natural configurations.
• The OH groups will be on the right, these are chiral
o Conformation: not breaking but rotating carbon bonds
▪ Hexose conformations can be boat or chair
▪ Pentose conformations can be C2 endo or C3 endo
▪ Haworth projections: can be alpha (OH points down) or beta (OH points up).
▪ Anomeric carbon: most oxidized carbon of a cyclized monosaccharide
Metabolism
▪ Metabolism: this is the entire network of biochemical reactions that occur in living cells
▪ Metabolites: the substrates, reaction intermediates and products in a metabolic pathway
▪ Catabolism: the breakdown of macromolecules that contain energy
o Energy is conserved in the process, to molecules like NADH oxidation reactions.
o Coupling is important because the electrons allow for the generation of ATP. If there are no electrons,
bond energy is lost, ATP cannot be made and cells would be depleted of energy.
▪ Anabolism: building of macromolecules
o Energy consumed in the process, reduction reactions.
o NADH can build molecules in anabolic rxns
What are the characteristics of metabolic pathways?
▪ They are sequences of reactions – linear pathways, circular pathways and spiral pathways
a. Linear may use intermediates from other pathways or branch to make new products
i. Glycolysis and O.P.
b. Circular allow for product to become the initial substrate
i. Other substrates are used from other pathways and some intermediates made leave the cycle as
products.
ii. TCA and Urea
c. Spiral pathways: the same enzyme can make an enlarged/elongated product
i. Lipid and Nucleic Acid Metabolism
▪ Metabolic pathways have specific steps that are produced under moderate conditions with low substrate
concentrations, specific enzyme, production of energy at specific steps.
▪ Metabolic pathways are regulated
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Document Summary
Lipids: water insoluble molecules that function in, structural components, energy storage, vitamins. Fatty acid: keeps the oh until pka: 4. 5-5. If there are no electrons, bond energy is lost, atp cannot be made and cells would be depleted of energy: anabolism: building of macromolecules, energy consumed in the process, reduction reactions, nadh can build molecules in anabolic rxns. Localizing the pathway sometimes occurs in a specific cell structure or cell type to allow for compartmentalization. Atp: product of catabolic reaction, energy source for anabolic reaction, hydrolysis will release energy and the energy is contained in the phosphoanhydride bonds, what three factors of atp and hydrolysis product drive the reaction, 1. Resonance stabilization adp/pi have more resonance more stable: 2. Normally at ph 7 the charges repel because they are so close together and are bound by positive mg2+: 3. Hydration more water can bind to adp and pi which increases entropy. This occurs upon inserting in a polar solvent.
