Chapter 1: Biochemistry and the Organization of Cells – Flashcards
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the reactions of biomolecules can be described by what?
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organic chemistry
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what is a functional group and what does it show?
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it's an atom or a group of atoms that show characteristic physical and chemical properties
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is it easy to synthesize or hydrolyze ATP?
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it's easy to hydrolyze it, but hard to synthesize it
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has the temperature been increasing or decreasing since the "big bang"?
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decreasing
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what elements were probably present at the beginning of the universe?
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H, He, and Li
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how were the other elements formed?
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thermonuclear reactions in stars, explosions of stars, the action of cosmic rays outside the stars
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Gases present in the atmosphere of the early earth?
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NH3, H2S, CO, CO2, CH4, N2, H2, and H2O
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experiments have demonstrated that what important biomolecules could have arisen under abiotic (nonliving) conditions from reactions of these simple compounds [where]?
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important biomolecs such as proteins and nucleic acids could have arisen under reactions from these simple compounds in the earth's oceans and on the surface of clay particles
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living cells include what very large molecules? these large molecules are classified as WHAT, made from WHAT? living cells also can include
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proteins, nucleic acids, polysaccharides, and lipids they are polymers, derived from monomers they can also include very small molecs, such as ions, metals, metabolites, amino acids
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proteins are polymers of?
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amino acids (monomers)
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nucleic acids are polymers of?
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nucelotides
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polysaccharides are polymers of?
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monosaccharides
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lipids are polymers of?
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glycerol and 3 fatty acids
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what is an enzyme? the effectiveness of an enzyme depends on what?
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an enzyme is a class of proteins that displays CATALYTIC ACTIVITY. the catalytic effectiveness of a given enzyme depends on its amino acid sequence
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what is the genetic code? the theories of the origin of life consider what?
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the relationship between the nucleotide sequence in nucleic acids and the amino acid sequence in proteins they consider how such a coding system might have arisen
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catalytic activity is associated with what? coding is associated with what?
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catalytic activity is associated with proteins, while coding is associated with nucleic acids
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certain types of RNA have what and are able to do what?
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certain types of RNA have catalytic activity and are capable of coding their own REPLICATION
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what is considered by scientists to have been the original coding material? where does it still serve this function?
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RNA, in some viruses
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what was a pivotal point in the origin of life?
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the appearance of a form of RNA that was capable of coding for its own replication
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the "original" RNA did what 2 things? how did this evolve?
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it encoded for and catalyzed its own replication in time, the system evolved to encode for the synthesis of protein catalysts
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what happened to RNA's role once DNA became the primary genetic materiaL?
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RNA took on an intermediary role in the synthesis of proteins
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key point in the development of livig cells?
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formation of membranes separating cells from environment
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one theory of the origin of life focusing on proteins, shows what aggregating to produce what?
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proteinoids aggregating to form microspheres (whatever this means?)
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what is the double-origin theory?
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the development of a coding system and the devlopment of catalysis came about separately; the two later combined to produce life
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what happens with replication without compartmentalizaiton by cell membrane? with compartmentalization?
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self-replicating RNA molecs, wher1 can direct protein syntehsize. the protein catalyzes reactions for ALL RNA with compartmentalization, the protein made by the cell's RNA is retained for use in the cell. the RNA can be selected on the basis of its use as a more effective catalyst
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assisted replication and reproduction (cold versus hot side of the pond)
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on the cold side, single RNA strands acted as templates on which nucleotides formed base pairs, making double strands on the hot side, heat woul dbreak the double strands apart, membranes could slowly grow, until the protocells divided into "daughter" protocells and repeated the cycle
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describe the journey of the first protocell to DNA-based cells like bacteria
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sac of water and Rna that requires external stimulus to reproduce--> next, ribozymes arise and help speed up reproductino and strengthen the protocell mebrane. protocells are now able to reproduce on their own--> next, other ribozymes catalyze metabolism and allow protocells to tap into nutrients from the environment
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general characteristics of prokaryotes, INCLUDES what groups?? single/multi celled?
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single-celled organisms "before the nucleus" that include bacteria and cyanobacteria
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general characteristics of eukaryotes? can include what examples? single/multi celled?
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"true nucleus". contain a well-defined nucelus surrounded by a nuclear membrane. single cells, such as yeast or Paramecium, or multicellular such as animals and plants
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nucleus: proks v. euks?
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no definite nucleus in proks; DNA present, but not separate from rest of cell present in euks
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cell membrane (plasma membrane): proks v. euks?
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present in both
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mitochondria: proks v. euks? (what do proks have instead?)
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proks: none; enzymes for oxidation reactions located on plasma mebrane euks: present
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endoplasmic reticulum: proks v. euks?
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proks: none Euks: present
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ribosomes: proks v. euks?
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present in both, but ribosomes techincally aren't an organelle
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chloroplasts: proks. v. euks?
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proks: none; photosynthesis (if present) is localized in chromatophores euks: present in green plants
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nucleus function?
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location of main genome; site of most DNA and RNA synthesis
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mitochondrion function?: what types of reactions occur here? does it have its own DNA?
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site of energy-yielding oxidation reactions; has its own DNA
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chloroplast function?: what species utilize this? does it have its own DNA?
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site of photosynthesis in green plants and algae; has its own DNA
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endoplasmic reticulum function? and what exactly is it made up of?
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continuous membrane throughout the cell: rough part studded with ribosomes (the site of protein syntehsis)
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golgi apparatus function? what's it made of?
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series of flattened membranes; involved in secretion of proteins from cells and in reactions that link sugars to other cellular components
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lysosomes functions?: what do they contain? what are they enclosed in?
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membrane-enclosed sacs containing hydrolytic enzymes
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peroxisomes functions?
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sacs that contain enzymes involve din the metabolism of hydrogen peroxide
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cell membrane function?: what does it contain within it? what holds organelles in place?
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separates the cell contents from the outside world; contents include organelles (held in place by the cytoskeleton) and the cytosol?
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cell wall function?
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rigid exterior layer of plant cells
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what is the central vacuole and where is it found?
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membrane-enclosed sac (plant cells)
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our classification system provides classification for eukaryotes that are.. what are the 5 kingdoms?
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neither plants nor animals kingdoms: Monera, Protista, Fungi, Plantae, and Animalia
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five kingdoms in order of increasing complexity? what types of organisms are found here?
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monera: prokaryotes protista: mainly unicellular eukaryotes fungi, plants, and animals: multicellular eukaryotes
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all cells require what to function?
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energy
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what is the ultimate source of energy for all life on earth? give examples of who uses this energy
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light from the sun photosynthetic organisms use light energy to drive the energy-requiring synthesis of carbohydrates non-photosynthetic organims consume these carbs for energy sources
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what does it mean if the free change in energy is negative?
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free energy decreases, and the reaction is spontaneous
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what does it mean if the free change in energy is positive?
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the reaction will not occur as written unless energy is supplied from an external source (the free energy increases)
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what is thermodynamics
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a branch of science that answers questions about processes that are energetically favorable
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what type of exchange happens in an open system (an example of an open system)? closed system? isolated system?
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open system: both energy and matter exchange. ex) a living organism (or a cell) closed system: only energy exchange isolated system: no exchange at all
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is a spontaneous reaction fast?
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not necessarily
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deltaG < 0 means what?
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spontaneous, exergonic reaction-->energy is released
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deltaG=0 means what?
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equilibrium
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deltaG>0 means what?
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nonspontaneous endergonic reaction. energy is required
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deltaG = what? (equation)
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DeltaG=DeltaH-TdeltaS where deltaH is enthalpy(heat) of a reaction at constant pressure deltaS is the change in entropy deltaG is the change in free energy T is temperature (in Kelvin)
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what happens if Hproducts>Hreactants? what happens if Hproducts<Hreactants?
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Hproducts>Hreactants, deltaH>0, endothermic reaction (heat flows into the system from the surroundings) Hproducts<Hreactants, delta H<0; exothermic reaction (heat flows from system to the surroundings)
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what does deltaH reflect on?
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the number and kinds of bonds
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deltaS is a measure of what?
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the amount of molecular disorder or randomness in a system
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what happens if Sproducts>Sreactants? what happens if Sproducts<Sreactants?
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Sproducts>Sreactants, deltaS>0; system has become more random Sproducts<Sreactants, deltaS<0, system has become less random
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do these suggested problems:
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1, 2, 6, 10, 11, 32, 33, 35-44, 49, 50
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