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This 3 page Class Notes was uploaded by Brenna Eisenberg on Monday October 3, 2016. The Class Notes belongs to 327 at Syracuse University taught by erdman in Fall 2016. Since its upload, it has received 4 views. For similar materials see Cell Biology in Biology at Syracuse University.
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What is Karma?
Karma is the currency of StudySoup.
Date Created: 10/03/16
Lecture 2&3 Thursday, September 8, 201610:47 AM Lecture 2 continued: • Chemically unfavorable reactions- condensation reactions, water is liberated 9/8/2016 11:17 AM - Screen Clipping • Constraints for living systems- chemistry and physics • Natural order towards disorder or entropy • Creating order requires energy, often coupled with activated carrier • 3 properties of sugars- ○ Ring formation, lots of hydroxyls and protons. Very soluble in water. ○ Isomers- differ only in spatial arrangement, same chemical formula different structural formula. Treated differently in the cell. ○ Polymer backbone can be branched. Forms selective barrier, allows water and charged polar molecules to pass well. Protective. • Fatty acids are amphipathic ○ Charged polar heads, hydrophilic ○ Tails are saturated carbons, not very polar. Hydrophobic. ○ Sterols are lipids that are important for the lipid membrane and producing steroid hormones Lipids also form micelles ○ ○ Majorly formed by phospholipids • Proteins: ○ Amino acids formed through series of condensation reactions, contain a peptide bond. ○ Contains an amino end and a carboxyl end ○ Proteins only exist as L-form isomers ○ 20 amino acids, can exist as both D and L isomers. ○ Svedburg determined the polymeric nature of proteins by ultracentrifugation. Sedimented as a band ○ Amino acids are linked by peptide bonds. ○ General types of amino acids: Acidic, basic, uncharged polar, nonpolar. Acidic and basic can make ionic bonds and interact strongly with water Uncharged polar often sites of modifications Hydrophobics important towards creating globular protein structures. hydrophobic Peptide bond Uncharged polar acidic Cell Biology Page 1 acidic Basic 9/8/2016 11:49 AM - Screen Clipping • Basic side chains- Positive charge. Ex-NH3 • Acidic side chains- negative charge. Ex: O- • Uncharged polar- OH group or NH2 group • Nonpolar side chains- No hydroxyl, sometimes rings, lots of methyl groups, generally hydrophobic ○ Cysteine- can make disulfide bonds. Can form between 2 cysteine side chains • Nucleic acids: ○ Pyrimidines and purines pair ○ G to C triple bonds ○ A to T double bonds ○ Nucleotides are hydrophilic. Phosphate and hydroxyl groups ○ Also carry energy (ATP, GTP), combine with other groups to form coenzymes(coenzyme A), used as signaling molecules. Lecture 3: • Generate order, liberate heat in the process • Catabolism creates useful forms of energy, heat, and building blocks for synthesis • Anabolism uses building blocks and energy to build molecules • The origin of energy is photosynthesis 9/8/2016 12:02 PM - Screen Clipping • Cells obtain energy through the oxidation of organic molecules • When ∆G is less than 0, the disorder of the universe increases. Can occur spontaneously. Energetically favorable. • Unfavorable reactions are coupled with other reactions • Equilibrium constant K: products/ reactants ○ At equilibrium, rates of forward and reverse reactions are equal • Unfavorable energy changes occur through: ○ Coupled reactions ○ The sum of ∆G must be negative for a reaction to occur Cell Biology Page 2 Cell Biology Page 3