Bio Exam 1 Study Guide Essay

Submitted By SmartyOwais1
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KEY NOTES CHAP 7 * The first view of cells: Robert Hooke’s drawing from 1665 (30X microscope) * Cells are dynamic. 1. Thousands of chemical reactions occur each second within cells 2. molecules constantly enter and exit across the plasma membrane 3. cell products are shipped along protein fibers 4. elements of the cell’s internal skeleton grow and shrink. * Electron micrograph(higher resolution than Light microscope) * fact that it was easily stained with early dyes, giving a colorful appearance (chromo = color; Soma = body; colorful body) * Flagellum move 60 cell lengths per min * Cell mitochondria received their name because they looked like threads in early microscopes * Ribosome (made up of rna and proteins) are in cytosol and ER * Eukaryotic Cells (Eu = ; karyo = ) typically 5-100 µm in size * Prokaryotes are 10 times smaller eukaryotic cells in diameter and 1000 times smaller in volume * Compartmentalization of eukaryotic cells - advantages: Separation of incompatible reactions Efficiency of chemical reactions is increased * Euchromatin: loosely packed sections of chromosomes * Heterochromatin: densely packed sections of chromosomes * Lumen is the inside of any sac-like structure * G apparatus Cis (“this”)side faces nucleus; Trans (“across”) side faces towards plasma membrane * Catalase - Enzyme in peroxisomes a Protein made up of 4 subunits (proteins made up of amino acids) * Catalase can convert 10^6 molecules of H202 to H20 per second! (H202 is also known as peroxide) * Lysosome= Interior is acidic - pH ~ 5.0; enzymes optimized to work at acidic pH * Vacuoles take up to 80% of space * Mitochondria and make their own ribosomes * Nuclear membrane has nuclear pores while cell membrane has everything… * * Kinesin- A motor protein that Carries vesicles Along microtubular Tracks From greek, “ ” (kinetics, cinema) Bind ATP, use Energy to move In one direction Down Microtubule track Tail region binds Cargo (vesicle), Head region grips microtubule

Central dogma: DNA codes for mRNA which codes proteins
Transcription - production of mRNA
Translation - synthesis of protein from mRNA
Autoradigraphy - radioactive tagging Chapter 3 key points * Hemoglobin is a protein - 4 subunits of globin; each globin has 1 heme group, which binds oxygen. Your body has LOTS of these proteins - 250 million per red blood cell; there are about 5 million red blood cells per milliliter; you have about 5 liters of blood in you … that’s a lot of hemoglobin … and every RBC is replaced every 120 days … A change in a single amino acid can Change properties dramatically (sickle cell anemia) (altering a glutamate to a valine) * In cells, most proteins are enzymes that function as catalysts…Chemical reactions occur much faster when they are catalyzed by enzymes. During enzyme catalysis, the reactants bind to an enzyme’s active site in a way that allows the reaction to proceed efficiently. * Proteins formed by peptide bonds between amino acids. Carboxl group of 1 amino acid interacts with the amino end of another – THIS IS A CONDENSATION RXN AKA DEHYDRATION REACTION H20 Is FORMED ..POLYMER IN H20 OUT * Enormous diversity of potential proteins…20^n possible