BSCI Exam 1 Study Guide Lecture 1 Introduction to the cell Chapter 1 8 CORE SIMILARITIES OF ALL CELLS 1 cells are highly complex and organized all cells plant animal and prokaryotic complex organization even in basic bacterial cells organized chemistry hierarchy of molecular organization Some structures we can see some we cannot 2 cells have a genetic program built based on info in genes hereditary genes construct proteins that make up cell info is the same for all cell types DNA is the universal language duplication by templated polymerization DNA info is copied as RNA so it can leave the nucleus DNA is the master copy RNA is easy to make Transcription from DNA to RNA RNA makes proteins to do stuff in the cell carry out activities DNA RNA protein proteins have tremendous diversity can catalyze reactions 3 cells can produce more copies of themselves cellular reproduction identical copies mitosis genetic change meiosis 4 cells are biochemical factories they are getting and making energy all the time cells need to have order and organization However the universe leans toward disorder So the cell needs energy to be ordered 5 cells can engage in mechanical activities can move things and provide structural support many proteins carry out cellular activities Ex motor proteins 6 cells respond to stimuli internal and external 7 cells have to regulate homeostasis and using feedback 8 cells are a point of evolution evolution begins at the cellular level Cell illustration with labeling Two major categories of existence eukaryotic prokaryotic large contains membrane bound nucleus small no membrane bound nucleus less detailed internal organization but it has organization that we cannot see optimized for rapid and efficient reproduction organotrophs phototrophs lithotrophs Cell size is constrained by S A ratio means cells must be relatively small to be able to get nutrients release waste etc Surface area needs to provide functionality for internal processes Membrane folding can allow cell to be a bit larger Tree of life Genetic change random positive negative and neutral effects all lead to evolutionary change new genes arise from existing change can happen rapidly or hardly at all effects of diversity innovation can occur many ways Gene families homologs orthologs diverge between separate organisms after speciation paralogs diverge in same environment organism before speciation Endosymbiosis caused cells to obtain inner membrane bound organelles Eukaryotic cells have nucleus and organelles hybrid genomes due to genetic info from organelles predator engulfed other cells led to symbiotic relationships some of which evolved into organelles in the cell Model eukaryotes well known easy to study sequenced genomes can do mutagenesis to see what happens developmental sequence is known ex yeast thale nematode fruitfly mouse Visualizing cells Lecture 2 BE ABLE TO IDENTIFY WHAT TYPE OF MICROSCOPE AN IMAGE IS USING AND WHAT TECHNIQUE WOULD BE BEST FOR DIFFERENT SITUATIONS Drawbacks of light microscopy resolution limits how well we can discern one thing from another and see how far apart they are mitochondria are the smallest things we can clearly see with light microscopy magnification versus resolution Light wavelengths two waves in or out of phase effects light level Cells are tiny bags of water with some other stuff animal cells are colorless and transparent techniques used to make them visible under light microscopy staining phase contrast DIC sectioning FRET TIRF vital microscopy Fluorescence microscopy losing some wavelengths of light Confocal microscopy Increasing resolution electron microscopy Flow cytometry cell sorting Lecture 3 Biological Molecules The Building Blocks of Cells Carbohydrates highly soluble in water energy source structural support ex cellulose binding surface condensation hydrolysis sugar linkages above plane in ring beta below plain in ring alpha 2 glucose molecules can be linked together in 11 different ways glycogen alpha 1 4 linkage animal carbs can have other branches starch is energy carbs for plants Lipids Amino acids hydrophobic membrane barriers and an energy source polar and nonpolar ends amphipathic triglyceride stores energy in animals stored in cytoplasm of cells building blocks of protein can be metabolized for energy side chains can result in varying chemical properties ionizing and pH some ionize easily at a neutral pH condensation reaction forms peptide bonds resulting in polymers polypeptide chains GLYCOSIDIC AND ESTER BONDS Nucleotides building blocks of nucleic acids short term energy can have some different side groups polar charged very water soluble polynucleotides made with condensation reaction results in polymers RNA DNA ATP ATP major short term energy carrier in the cell ATP synthesis and hydrolysis cycle Bacterial cell components Biological order occurs on various scales Cells and thermodynamics 1st energy is constant it cannot be created or destroyed energy transformations are not completely efficient some is always lost cell can no longer use it lost as heat 2nd overall in a closed system processes are driven in the direction of disorder energy is needed to generate order energetically favorable things occur spontaneously Do cells violate the 2nd law No they are not isolated systems can exchange energy and materials with environment Lecture 4 Plasma membrane and plant cell wall The plasma membrane a defining characteristic of all cells walls boundaries controls what can go in and out of cell proteins in membrane provides functionality Phospholipids and functionality amphiphilic most abundant lipid in plasma membrane saturated and unsaturated polar head group can be different Sterols and membranes important components of membranes has rigid ring structures that can stiffen parts of phospholipids main sterol in animals is cholesterol plants is phytosterols fungi is ergosterol cholesterol can be abundant in animal cells Self assembly of phospholipid membranes makes self into lipid membranes head likes water tails like other tails stable arrangement minimizes free energy making it more favorable makes sphere to avoid water Lipid membrane properties liposomes black membranes membrane forms across a hole can be used to study the motion of individual lipid molecules The fluid mosaic model has leaflets flip flopping microdomains microdomains in the plasma membrane Membrane asymmetry shows how there are the inner and outer leaflets are not always
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