BCH5413 EXAM 1 STUDYGUIDE

Six principal elements - ANSWER carbon, hydrogen, oxygen, nitrogen, phosphorous, and sulfur. These make up 92% of the dry weight of cells Organic molecules can form three complex shapes - ANSWER straight structures, branched chains, or rings Hydrocarbons - ANSWER carbon- and hydrogen-containing compounds that are hydrophobic Metabolism - ANSWER The sum of all biochemical reactions. Functions of metabolism are: 1. Acquisition and utilization of energy. 2. Synthesis of biomolecules. 3. Growth and development 4. Removal of metabolic waste and other toxic substances. nucleophilic substitution reaction - ANSWER an atom with an unshared pair of electrons displaces a leaving group A: + B-X A-B + X: where A: is the nucleophile and X: is the leaving group An important type is a hydrolysis reaction Redox Reactions - ANSWER Redox reactions involve the transfer of electrons. Oxidation: a loss of electrons Reduction: a gain of electrons Oxidizing agent: the electron acceptor Reducing agent: the electron donor The two reactions are reciprocal and occur simultaneously. biochemistry redox reactions - ANSWER Oxidation occurs when a molecule loses two hydrogens and/or gains an oxygen. Reduction occurs when a molecule gains two hydrogens and/or loses an oxygen Energy - ANSWER the capacity to do work . The more reduced the molecule, the more energy it contains Anabolic (biosynthetic) pathways: - ANSWER large complex molecules are synthesized from smaller molecules Requires energy Catabolic pathways: - ANSWER large complex molecules are degraded into simpler products Stores energy: a portion of the energy produced drives anabolic reactions Provides energy and materials for anabolic processes Systems Biology - ANSWER Emergence -Interaction of parts can lead to new properties Robustness -Many biological systems remain stable despite perturbations Modularity -Complex systems are composed of modules Eukaryotic Cells - ANSWER Have nucleus Water - ANSWER dissolves hydrophilic molecules and many ionic compounds. Hydrophobic molecules are pushed out of solution by water. They typically form clusters to minimize contact with water. Biological membranes - ANSWER are flexible structures (usually lipid bilayers) that provide a selective physical barrier, preventing contents from leaking out and other molecules from getting in Prokaryotes - ANSWER Lack nucleus -Two groups a. Bacteria b. Archaea Three shapes of bacteria - ANSWER Rodlike (bacilli) Spheroidal (cocci) Coiled (spirilla) Gram-positive - ANSWER A peptidoglycan rigid cell wall maintains shape and classifies the bacteria Gram-negative - ANSWER A peptidoglycan rigid cell wall AND an outer lipid bilayer classifies the bacteria Nucleoid - ANSWER circular DNA molecule or chromosome. Plasmids - ANSWER small circular DNA molecules separate from the chromosome. Pili - ANSWER fine hair-like structures that allow for attachment to food sources and host tissues. Smooth Endoplasmic Reticulum - ANSWER -Lipid synthesis -Biotransformation: water-insoluble organic molelcules are prepared for excretion Rough Endoplasmic Reticulum - ANSWER The rough endoplasmic reticulum is involved in the production of membrane proteins and proteins for cell export. a type of cell that is found in multi-cellular organisms, possesses a nucleus as well as other organelles and has linear DNA. - ANSWER _Eukaryokic___ a biological cofactor that acts as an oxidizing agent in REDOX reactions. - ANSWER NAD+_____ the major class of biomolecules that are not biopolymers (long chain of a common building block) and are largely hydrocarbon in content. - ANSWER Fats (or Lipids)____ refers to molecules that posses few if any electronegative atoms and therefore do not dissolve readily in water. - ANSWER Hydrophobic the non-covalent force of attraction that gives rise to water's high specific heat and heat of vaporization. - ANSWER H-bonds a solution that has a higher solute concentration than a cell it surrounds, thus causing the cell to shrink in a process called crenation. - ANSWER Hypertonic Site of lipid synthesis and biotransformation (preparation of water-insoluble organic molecules for excretion) - ANSWER Smooth Endo. Reticulum Involved in the packaging and distribution of cell products to both internal and external cell compartments, often includes transport using vesicles. - ANSWER Golgi Apparatus A network of proteinaceous fibers and filaments that provide for the maintenence of cell a supporting network that guides the movement of organelles. - ANSWER _Cytoskeleton Separates the eukaryotic cell from its external environment, composed of lipids and proteins, and has a role in intercellular communication. - ANSWER _Plasma Membrane An intricately folded membrane system that is responsible for several chloroplast metabolic functions. - ANSWER Thylakoid _____ Contains the cells hereditary information, DNA, and exerts a profound influence on cellular activities, it is surrounded by an envelope of two membranes fused at pores where molecules and ions enter and leave - ANSWER _Nucleus_________ a. What are the two required components of a buffer system? - ANSWER HA - a weak acid or A- - a weak base Must have a A-- its conjugate base HA - its conjugate acid common anion a. Using a chemical equation, show how a strong base (OH-) is neutralized when added to a buffer: - ANSWER HA + OH- H2O + A-