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Introduction to Cell Physiology. Slides by John R. Waters, Anatomy and Physiology at Penn State available at: www.bio.psu.edu/Courses/Fall2002/Biol141-Everything/powerpoint/All_the_intro_concepts_SummerB/. What is physiology?.
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Introduction to Cell Physiology Slides by John R. Waters, Anatomy and Physiology at Penn State available at: www.bio.psu.edu/Courses/Fall2002/Biol141-Everything/powerpoint/All_the_intro_concepts_SummerB/
What is physiology? • The branch of biology dealing with the functions and activities of living organisms and their parts. • The study of bodily function that primarily employs the methods of experimental science.
Biological Organization (pg.17)A hierarchy of structural complexity • The organism,
Biological Organization (pg.17)A hierarchy of structural complexity • The organism is composed of organ systems
Biological Organization (pg.17) A hierarchy of structural complexity • The organism is composed of organ systems organs systems are composed of organs,
Biological Organization (pg.17) A hierarchy of structural complexity • The organism is composed of organ systems organs systems are composed of organs, organs are composed of tissues,
Biological Organization (pg.17) A hierarchy of structural complexity • The organism is composed of organ systems organs systems are composed of organs, organs are composed of tissues, tissues are composed of cells,
Biological Organization (pg.17) A hierarchy of structural complexity • The organism is composed of organ systems organs systems are composed of organs, organs are composed of tissues, tissues are composed of cells, cells are composed partially of organelles,
Biological Organization (pg.17) A hierarchy of structural complexity • The organism is composed of organ systems organs systems are composed of organs, organs are composed of tissues, tissues are composed of cells, cells are composed partially of organelles, organelles are composed of molecules,
Biological Organization (pg.17) A hierarchy of structural complexity • The organism is composed of organ systems organs systems are composed of organs, organs are composed of tissues, tissues are composed of cells, cells are composed partially of organelles, organelles are composed of molecules, molecules are composed of atoms,
Biological Organization (pg.17) A hierarchy of structural complexity • The organism is composed of organ systems organs systems are composed of organs, organs are composed of tissues, tissues are composed of cells, cells are composed partially of organelles, organelles are composed of molecules, molecules are composed of atoms, and atoms are composed of subatomic particles
Chemical Bonds (58-60) • Atoms can be bound together to form molecules • 2 H+ + O--H2O (water) • Na+ + Cl- NaCl (sodium chloride) • 6 C + 12 H+ + 6 O-- C6H12O6 (carbohydrate)
Chemical Bonds (58-60) - O H H + • The atoms that form molecules are bound together by chemical bonds • covalent bond • electrons shared between atoms • single (C-C) • double (C=C) • non-polar (C-C) • polar (O-H) • water • ionic bond • oppositely charged ions are attracted to one another • NaCl • hydrogen bond • weak bond between a slightly positive hydrogen and a slightly negative oxygen or nitrogen
Chemical Bonds - hydrogen bonds (58-60) - O H H + • hydrogen bond • weak bond between a slightly positive hydrogen and a slightly negative oxygen or nitrogen
Molecules and chemical reactions (66, 68) • Chemical bonds between molecules can be formed or broken during chemical reactions • Metabolism is all of the chemical reactions occurring in your body • catabolism (breaking down a molecule) • energy released during chemical reaction • EX. carbohydrates are broken down to release energy • anabolism (synthesizing or building a molecule) • energy required for chemical rxn • EX. energy is used to build proteins or make ATP.
Molecules and chemical reactions – ATP (96-97) • ATP (adenosine triphosphate) is a molecule synthesized by organisms to store energy in a readily usable form. • The energy is stored in the chemical bonds of ATP molecules as chemical potential energy • ADP + P + energy -> ATP • This energy can be used by cells whenever they need to do work. • ATP -> ADP + P + energy
Life requires about 25 chemical elements • 96% of living matter is made up of • C • O • N • H • the other 4% is mostly P, S, Ca, and K • plus some trace elements like Fe and I
Most macromolecules are polymers (80) • Monomers are basic subunits used to build polymers(smaller molecules) (larger molecules) • We will focus today on two polymers • lipids • proteins
Lipids are mostly hydrophobic molecules with diverse functions (85-87) • Fats
Lipids are mostly hydrophobic molecules with diverse functions (85-87) • Phospholipids
Lipids are mostly hydrophobic molecules with diverse functions (85-87) • Phospholipids form stable structures in water
Proteins (87-92) H H H O H O N C C N C C H OH H OH R1 R2 • Proteins are the molecular tools for most cellular functions • A protein is a polymer of amino acids connected in a specific sequence
Proteins (87-92) H H H O H O + N C C N C C H OH H OH R1 R2 H O H H H O N C C N C C + HOH H OH R1 R2 • Proteins are the molecular tools for most cellular functions • A polypeptide is a polymer of amino acids connected in a specific sequence
Proteins (87-92) • Proteins are the molecular tools for most cellular functions • A polypeptide is a polymer of amino acids connected in a specific sequence • 20 different amino acids (aa) • Each aa has a differentR group
Proteins (87-92) • Proteins are the molecular tools for most cellular functions • A polypeptide is a polymer of amino acids connected in a specific sequence • 20 different amino acids (aa) • Each aa has a differentR group • Polar (+ or - charge) • hydrophilic
Proteins (87-92) • Proteins are the molecular tools for most cellular functions • A polypeptide is a polymer of amino acids connected in a specific sequence • 20 different amino acids (aa) • Each aa has a differentR group • Polar (+ or - charge) • hydrophilic • Non-polar (no charge) • hydrophobic • hydrogen, ionic, covalent bondsbetween R groups are also possible
Proteins (87-92) • A protein’s function depends on its specific conformation • primary structure • secondary structure • tertiary structure • quaternary structure • Proteins are the molecular tools for most cellular functions • A polypeptide is a polymer of amino acids connected in a specific sequence
Remember…. A molecule’s biological function is related to its shape
Biochemical Example of Feedback Control Glycolysis: a metabolic pathway Negative Feedback Input (Glucose) Output (ATP) … … X X X X 0 1 i n perturbation X_i : metabolites (small molecules derived from glucose) : chemical reactions (each catalyzed by an enzyme)
Enzyme-Catalysed Reactions http://www.uyseg.org/catalysis/principles/images/enzyme_substrate.gif
http://www.eccentrix.com/members/chempics/Slike/Enzyme/2Competitive_inhibition.jpghttp://www.eccentrix.com/members/chempics/Slike/Enzyme/2Competitive_inhibition.jpg
Allosteric Regulation http://courses.washington.edu/conj/protein/allosteric.gif
A Regulated Enzyme: Phosphofructokinase (PFK) Reactants: Effector: Product:
How can biochemicals regulate enzyme activity?By inducing conformational changes
A DNA strand is a polymer with an information-rich sequence of nucleotides
DNA (deoxyribonucleic acid) Chain composed of bases: A, C, G, T http://genetics.gsk.com/graphics/dna-big.gif
Some segments of DNA code for proteins Other segments of DNA code for RNAs (e.g. tRNAs or rRNAs.) http://www.designeduniverse.com/articles/Nobel_Prize/trna.jpg
Still other segments of DNA are regulatory regions. Repression Activation http://www.emc.maricopa.edu/faculty/farabee/BIOBK/repressor_1.gif
Basic structure of a cell (104-108) • plasma membrane • cytoplasm • organelles • vesicles • mitochondria • nucleus • many others • proteins • structural • enzymes
Basic structure of a cell - plasma membrane (108-112) • lipid bilayer • membrane proteins • gates/pores • pumps • receptors • Plasma membranes will let some things pass, but not others • They are semipermeable
Carrier mediated transport (128-131) ATP • Requires membrane proteins • Two types of carrier mediated transport • facilitated diffusion • proteins channels just act as doors • just diffusion • no energy required • active transport • substances moveagainst theirconcentration gradient • move from an areaof low concentration... • to an area of high concentration • Requires ENERGY