BIOLOGY 151 1st EditionExam # 1 Study Guide Lectures: 1 – 14Lecture 1 - 1/21Species, Evolution, and Cells:- species - a group of physically similar organisms (that can interbreed in nature if they are sexually reproductive). - taxonomy - put species into groups.-hierarchical system developed by Carl Linnaeus (1700s)Are species stable?:- assumption of species stability, but...- changed during 1800s by:-geology: Earth not 5,000 years old, modern estimate = 4.6 billion years-fossil record: -old species have vanished-current species missing from old fossils-new species appearing in new habitats?-new species on new islands?-new finch species on the Galapagos Island-new species on new volcanic island?-old species on mainland?Does new life have to come from old life or spontaneous generation?:- life could arise from non-living substances?- common sense for most of human history- discovered in 1668 for maggots by Redi, 1700s for other multicellular organisms-uncovered = maggots-covered = no maggots- new species evolved from old speciesWhat about cells?:- invention of microscope- Robert Hooke (1655) called hollowLecture 2 - 1/23What about cells?:- invention of microscope- Robert Hooke (1655) called hollow pores in cork "cells" (like little rooms)- van Leeuwenhoek in 1600s found single-celled organisms which he called "animalcules"- one lens microscopeThe Cell Theory (Mid 1800s):- "Every animal appears as a sum of vital units (cells), each of which bears in itself the complete characteristics of life."- "omnis cellula e cellula" - Modern version - 1. All living organisms are made of cells (and the products of other cells). 2. All cells are produced by other cells.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Louis Pasteur (1860s)- boil broth (soup) - no cells- wait: cells appear (and it stinks)- seal the top: Needham (1745, sterile broth still generated life) vs. Spallanzani (no it didn't)- no spontaneous generation, or life needs air?- Pasteur's experiment (1862)- all cells come from other cells (part 2 of the cell theory)-cells divide to produce new cellsWhy would species evolve?:- Darwin, Wallace and the theory of natural selection:1. There is variation of traits within the population of individuals that make up a species. 2. Those traits are heritable. 3. Certain traits allow better survival of individuals. Is the theory of natural selection correct?:- Why is there variation in traits?- Why are traits "heritable" and how heritable are they?- How do cells work and reproduce?- Where did cells come from?Cells are mostly water:1. Many chemicals dissolve in water.- Dissolved molecules can diffuse between parts of a cell - diffusion.- Covalent bonds are formed by sharing electrons between 2 atoms.- Want to fill outer valence shell.- Electronegativity - how much an atom attracts electrons.- Polar covalent bond - unequal electron sharing gives parts of molecules partial electric change - O and N like electrons more than H or C- H and C like electrons equallyIons and Ionic Bonds:- When atoms completely gain or lose electrons, they form ions-electrons not shared- ionic bond: attraction between plus and minus charge- polar molecules (and ions) can be attracted by hydrogen bonds-electrical attraction between positively and negatively charged ends-1/20th strength of a covalent bond- ions and polar molecules dissolve in water due to hydrogen bonding- water can ionize -H20 breaks into H+ and OH-pH = -log10[H+]-acids and bases (low vs. high pH)Water Properties:- water binds to charged or polarized molecules and surfaces - "adhesion" of water to hydrophilic molecules- water binds to water = "cohesion"- solid water (ice) molecules are packed less densely than liquid water molecules - ice floats in water- water requires higher heat input to increase temp. than many other substances - high specific heat- greater spacing between water molecules in ice- hydrogen bonding between moleculesLecture 3 - 1/26What is in the water in living cells?:- ions (including water ions), minerals - similar to sea water- carbon-containing compounds = organic molecules- covalent bonds are formed by sharing electrons between 2 atoms - atoms want to share enough electrons to fill their outer valence shell- innermost shell: full = 2- outermost shell: full = 8- organic molecules can make long chains with carbon-carbon bonds (single bonds or double bonds)Carbon-containing organic molecules:- structure (and movement)- reacts to make other molecules- energy storage in bonds, electrons- control of chemical reactionsStructural question: will an organic molecule dissolve in water?:- oxygen or nitrogen will polarize bonds = hydrophilic (likes water)- hydrocarbon chains (with just carbon and hydrogen) are nonpolar = hydrophobic (scared of water)Hydrophobic interactions:- water likes water, pushes hydrophobic molecules (or parts of molecules) awayChemical bonds:- strong: covalent bonds (sharing electrons)- weak:-hydrogen bonds (electrical attraction between polarized molecules)-van der Waals interactions-hydrophobic "bonds" - hydrophobic molecules "hide" together, away from waterExamples of chemical reactions:- the breakdown of sugar- the synthesis of sugar- First Law of Thermodynamics - the total energy of an isolated system is constant; energy can be transformed from one form to another, but cannot be created or destroyed.- Second Law of Thermodynamics - there is an increase in the sum of the entropies (disorder) of the participating systems. Molecules contain potential energy in bonds, electrons:- kinetic energy = energy of motion- potential energy = the stored ability to cause motion-break bond = released potential energy becomes kinetic molecular motion = heat, or can be used to makeanother chemical bond.What makes a reaction "spontaneous" (favored)?:- depends on temp., the release of energy from bonds, changes in entropy = changes in Gibb's Free Energy (delta G)- spontaneous reactions release free energy (-delta G) = exergonic- non-spontaneous reactions absorb free energy (+delta G) = endergonic- Energy of activation is lowered through the use of an enzyme- required to form an "active" intermediate in the reaction- not stored - used, then released by the reaction- catalyst - compound that lowers activation energy needed for reaction-allows intermediate action to allow at lower temp. Enzymes - biological catalysts