Important Things from Chapter 1Prokaryotic:o Evolved before Eukaryotico Do not have nucleuso Genetic material resides in cytoplasmo Lack membrane bound organelleso Bacteria and Archaea Eukaryotico True membrane enclosed nucleuso Largero Contain a variety of other organellesBacteria & Archaeao Unicellularo Auto (Self Feeding) or Heterotrophic (Other Feeding)Fungi – Multicellular, HeterotrophicPlantae – Multicellular, AutotrophicAnimalia – Multicellular, Heterotrophic“Protists” – Uni & Multicellular, Auto or Heterotrophic1. What are the 7 characteristics that all organisms share?Composed of cells, maintain homeostasis, respond to stimuli, use and convert materials and energy, grow, reproduce, and evolve2. What are the characteristics of life that viruses lack? Name those that they have.They don’t grow, aren’t made of cells, don’t require nucleus. Reproduce and evolve.3. What are the 3 domains of life? How are they different/similar? (Single-celled and/or multicellular organisms, heterotrophs, autotrophs, prokaryotic, eukaryotic) Bacteria – single celled, archaea – single cell, and eukarya – multicellular.4. How are prokaryotic cells and eukaryotic cells different. What cell structures do they both have?Pro has no nucleus and is smaller, Euk has nucleus and is larger.5. Species names are made up of what part(s)? Also, put all categories in order from domain to specific epithet.6. What are the levels of life from atoms to the biosphere?7. What is the purpose of the scientific method? What are the parts of the scientific method? What are variables?8. How are hypotheses different from theories?Chapter 2 Atoms, Molecules and Life Part 1What Are Atoms? How Do Atoms Interact to Form Molecules? Why is Water So Important to Life? Atoms are the fundamental structural units of matter and are composed of three types of particlesIn the nucleus, there are positively charged protons and uncharged neutrons.In orbit around the nucleus are negatively charged particles called electrons.Atoms are electrically neutral because their number of protons and electrons is equal - The ____________________________ in the nucleus of an atom atomic mass of an element is the total mass of its protons, neutrons, and electronsAtomic ModelsElementsAn element is a substance that cannot be broken down by ordinary chemical reactions. Have unique chemical and physical propertiesAt room temperature they can be gasses (ex: hydrogen), liquids (ex: mercury), or solids (ex: lead)There are 92 types of naturally occurring elementsThe atomic number (number of ??) is the defining value for an elementAll atoms of an element have the same atomic numberFor example, carbon has six ??, nitrogen has sevenDiamonds and graphite are both pure carbon, but the arrangements differThese elements compose about 96% of human body weight oxygen, carbon, hydrogen, and nitrogenThese are known as the “building blocks” of life on earthIsotopesAtoms of an element may vary in the number of neutrons they have in the nucleusVariant forms are called isotopesSome isotopes are radioactive (meaning that they spontaneously break apart, forming different atoms and releasing energy) and are used in research – not radioactive: carbon 12 & 13Radioactivity in research: positron emission tomography (PET) scan. Subject is given the sugar glucose with a radioactive isotope of fluorine attached, tumor cells use large amounts of glucose so radioactivity is highest there.Author Animation: Atomic StructureHydrogen isotopes: DeutrtiumElectron shellsElectrons are found in electron shells around the atoms nucleusThe first shell, or energy level, holds two electronsSubsequent shells holds up to eightWhile the nucleus provides stability, the electrons interact with other atoms (for example, to form chemical bonds)Chemical bonds are the force of attraction between atoms that holds them together within a moleculeElectron shell – restricted 3D spaces within which electrons orbit the atomic nucleus– Fig 2.2Life depends on electrons capturing and releasing energy-Electron shells correspond to energy levelsWhen energy excites an atom, it causes an electron to jump from a lower to a higher energy shellLater, the electron falls back into its original shell, releasing the energy (see fig. 2.3)Electrons can absorb and release energy. Electricity flows though filament causing heat. Heat bumps electrons into higher energy electron shells. As electrons fall back to their original shells they release energy as lightMolecules consist of two or more atoms, from the same or different elements, that are held together by interactions among their outermost electron shellsA substance made of atoms of different elements is a compoundReactions between atoms depend upon the configuration of electrons in the outermost electron shellAtoms interact when there are vacancies in the outermost electron shellsReactions that fill or empty outer electron shells, produce stable chemical bonds (coming up!)If the outermost shell is completely empty or full, atoms will not react with other atoms (considered inert)Example: Neon, eight electrons in its outermost shell- is fullBUT, atoms will react with other atoms if the outermost shell is partially full (considered reactive)Example: Oxygen, six electrons in its outermost shell, can hold two more electronsReactive atoms gain stability through electron interactions (chemical reactions)1. Electrons can be lost___ from outermost shell2. Electrons can be gained__ (added to outermost shell)3. Electrons can be shared__ with another atom when both atoms have full outermost shells1 Hydrogen atom and 2 oxygen atoms = waterHydrogen and oxygen atoms gain stability by interacting with each otherSingle electrons from each of two hydrogen molecules fill the outer shell of an oxygen atomFree radicals form when reactions cause molecules to have atoms with unpaired electrons in their outer shellsHighly reactive free radicals can damage cellsFree radicals steal or donate electrons, destroying other moleculesCell death can occur and lead to heart disease and Alzheimer’s from free radical attackCause of free radicals: sun, x-rays, cigarette smoke, and cellular processes that require oxygenAntioxidants: vitamin C, A, E, lycopene, beat-carotene, luteinChemical bonds hold atoms together in moleculesA chemical reaction is a process by which new chemical bonds are formed or existing bonds are broken, converting one substance into
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