Cell Bio Exam Notes (AutoRecovered) (1).docx - Section 1...

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Section 1 DNA: Antiparallel, double helical strands of A, C, T, G bases held by H bonds - Deoxyribose sugar (A&T forms 2 bonds); A/G are Purines C/T are Pyrimidines (1) mRNA : Intermediates encoding the protein; each amino acid = 3 nucleotides (codon) -codons are translated into protein by ribosomes tRNA : intermediate that matches mRNA codon to its corresponding amino acid rRNA : structural RNA molecule that binds ribosomes along with ribosomal protein 1 ST Law of TD : Spontaneous reactions reduce enthalpy and increase entropy of system 2 nd Law of TD : Conversion of PE>Work always comes w/ transformation to heat and +∆S Entropy : Randomness/disorder of a system ((+∆S = spontaneous) Enthalpy : Energy content of chemical bonds (+∆H = nonspontaneous) Gibbs Free Energy : Energy available to do work ((+∆G = nonspontaneous); ∆G= ∆H - T∆S Catabolism : Highly exergonic/spontaneous reactions; +∆S and -∆H; breakdown of sugars/lipids Anabolism : Highly endergonic/non-spontaneous reactions: -∆S and +∆H; protein synthesis Prokaryotic Cell Eukaryotic Cell Lacks a nucleus enclosing the DNA Lacks membrane-bound organelles Bacteria and archaea Membrane-bound nucleus present Contains membrane-bound organelles LUCA : Last organism that was common ancestor to Prokaryotes, Eukaryotes, and Archaebacteria - 3.5 billion years ago; had lipid-synthesizing enzymes for membranes, complex enzymes and pathways Ribosome : Enzymes responsible for translation Nucleus : Part of nucleus responsible for RNA splicing Centrioles : Controls formation of microtubules Cytoskeleton : Protein filaments that give shape/strength/movement to cells Plasma membrane: Defines cell w/ semi permeable membrane that separates inside from out Nucleus : Double lipid bilayer that encloses/protects DNA ER : Biosynthesis of lipids/proteins Golgi Apparatus : Processing of lipids/proteins and sorting to different parts of the cell Peroxisomes : Redox reactions and synthesis/breakdown of some lipids Endosomes : Results from endocytosis of material from plasma membrane; involved in sorting material Lysosomes : Degradation of membrane and proteins Mitochondria : Oxidation of energy molecules to make ATP (Via oxidative phosphorylation/respiration) Chloroplasts : Found in plats/algae – which uses light to make sugars from CO 2 + H 2 O Nucleus Evolution : From in-folding of plasma membrane of ancient prokaryotic cell to protect DNA Eukaryotic Origin: 1. Primordial pre-eukaryotic cells may have been predatorial (ate cells via phagocytosis)’ 2. Cytoskeletal filaments drive the required change in cell shape 3. Nuclear enclosure allows protection from DNA entanglement/damage
Mitochondria/Chloroplasts : Double bilayer, own genome, ribosomes, and tRNA Mitochondria Evolution : 1. Ancestral anaerobic predator cell engulfed an aerobic bacterium 2. Large cell protected/provided food, small cell oxidized food to produce ATP (symbiotic) 3. Symbiotic relationship became permanent via loss of redundant genes Chloroplast Evolution: 1. Mitochondria-containing Eukaryotic cells engulfed cyanobacteria 2.

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