Biology 1 exam 2

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Jharp1981
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Biology 1 exam 2
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2010-03-28 22:34:20
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Bio2 Exam 2 Limas
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membranes, metabolism, cellular resp, photosynth, cell cycle
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  1. An adenine-containing nucleoside triphosphate that releases free energy
    when its phosphate bonds are hydrolyzed. This energy is used to drive
    endergonic reactions in cells.
    ATP
  2. The movement of a substance across a cell membrane, with an expenditure
    of energy, against its concentration or electrochemical gradient;
    mediated by specific transport proteins.
    Active Transport
  3. Having both a hydrophilic region and a hydrophobic region.
    Amphipathic
  4. An adenine-containing nucleoside triphosphate that releases free energy
    when its phosphate bonds are hydrolyzed. This energy is used to drive
    endergonic reactions in cells.
    Aquaporin
  5. Membranes have been chemically analyzed and found to be made of?
    Made of Proteins and Lipids
  6. Effects of Cholesterol on membranes fluidity at warm temperatures, (such as 37 C)
    restrains movement of phospholipids at warm temps
  7. Effects of Cholesterol on membranes fluidity at COOL temperatures
    maintains membrane fluidity by preventing tight packing
  8. Integral proteins that span the membrane
    transmembrane proteins
  9. They hydrophobic regions of an integral protein consist of one or more stretches of
    nonpolar amino acids, often coild into alpha helices
  10. Six major functions of membrane proteins?
    • Transport
    • Enzymatic activity
    • Signal transduction
    • Cell-cell recognition
    • Intercellular joining
    • Attachment to the cytoskeleton and extra cellular matrix (ECM)
  11. cells recognize eachother by _______,often carbohydrates, on the plasma membrane.
    binding to to surface molecules
  12. The asymmetrical distribution of proteins, lipids, and associated carbohydrates in the plasma membrane is determined when__________.
    the membrane is built by the ER (synthesis of proteins lipids and carbs (glycoproteins) and Golgi apparatus (glycolipids formation from modifiying carbs)
  13. The permeability of the LIpid Bilayer involves ________, such as hydrocarbons, which can dissolve in the lipid bilayer and pass through the membrane rapidly, and _________, such as sugars, that do not cross the membrane easily.
    Hydrophobic (nonpolar) molecules AND Polar molecules
  14. Transport Proteins allow passage of _______ substances across the membrane and are______for the substance it moves.
    • hydrophillic substances
    • specific
  15. 2 types of transport proteins and function
    • aquaporins--facilitate the passage of water only
    • carrier proteins--bind to molecules and change shape to shuttle across membrane
  16. diffusion of a substance across a membrane with no energy investment
    (down the concentration gradient)
    ie diffusion, facilitated diffusion, osmosis
    Passive transport
  17. The control of water balance in cells without walls
    osmoregulation
  18. Channel proteins include
    • Aquaporins, facilitated diffusion of water
    • ion channels, open and close in response to a stimulus (gated channels)
  19. The kidney disease Cystinuria is caused by
    malfunctions in specific transport systems
  20. Sodium Potassium Pump steps of Na and K
    • 1. Na+ binds to pump, affinity for Na high
    • 2. Phosphorylation of protein by ATP
    • 3. Protein shape change, Na expelled, Affinity for Na low
    • 4. Affinity high for K, which binds and triggers release of phosphate inside cell
    • 5. loss of phosphate restores proteins shape, affinity Low for K
    • 6. K released, affinity high for Na again

    3 Na+ out for every 2 K+ in
  21. the major electrogenic pump for ANIMAL cells
    sodium-potassium pump
  22. Main electrogenic pump of PLANTS, fungi, and bacteria
    proton pump
  23. moves substances against conconetrations gradiant, requires energy ATP, performed by specific protens embedded in membranes, allows cells to maintain concentration gradients that differ from their surroundings
    active transport
  24. Large molecules such as polysaccs and proteins cross the membrane in bulk via ________, which requires________.
    vesicles AND energy
  25. Three types of endocytosis
    • Phagocytosis--engulfs a particle in a vacuole, lysosome digests particle
    • pinocytosis- molecules gulped into tiny vesicles
    • receptor-mediated endocystosis- binding of ligands to receptors triggers viscle formation
    • (ligands are any molecules that bind to a receptor site of another molecule)
  26. a miniature chemical factory where thousands o reactions occur. It also extracts energy and applies energy to perform work.
    living cell
  27. where some organisms convert energy to light
    bioluminescence
  28. the totality of an organisms's chemical reactions and an emergent property of life that arises from interactions between molecules within the cell
    metabolism
  29. begins with a specific molecule and ends with a product and each step is catalyzed by a specific enzyme
    metabolic pathway
  30. pathway that releases energy by breaking down complex molecules into simpler compounds ie hydrolysis, cellular respiration (exergonic)
    catabolic pathways
  31. this pathway consumes energy to build complex molectules from simpler ones
    ie the synthesis of protein from amino acids, dehydration (endergonic reaction-stores energy)
    Anabolic pathways
  32. the capacity to cause change, it exists in various from some of which can peform work; can also be converted from one form to another
    energy
  33. energy associated with motion
    kinetic energy
  34. kinetic energy associated with random movements of atoms or molecules
    heat (thermal energy)
  35. energy that matter possesses because of its location or structure
    potential energy
  36. potential energy available for release in a chemical reaction
    chemical energy
  37. the study of energy transformations
    thermodynamics
  38. As related to thermodynamics, organisms are _______ where energy and matter can be transferred between the system and its surroundings.
    open systems
  39. first law of thermodynamics
    • also called the "principle of conservation of energy"
    • Energy can be transferred and transformed, but it can neither be created or destroyed
  40. Second law of thermodynamics states
    Every energy transfer or transformation increases the entropy (disorder) of the universe
  41. During every energy transfer or transformation, some energy is unusable, an is often lost as
    heat
  42. Living cells unavoidably convert organized froms of energy to
    heat
  43. occurs without energy input; they can happen quickly or slowly
    spontanious processes
  44. For a process to occur without energy input, it must increase the
    entropy of the universe
  45. Less ordered materials are made into ordered structures by
    cells
  46. Organisms also replace ordered froms of ______ and _______ with less ordered forms.
    matter and energy
  47. Energy flows into an ecosystem in the form of _____ and exits in the form of _______.
    light ; heat
  48. The evolution of more complex organsims does not violate the ____ of thermodynamics.
    second law
  49. Entropy (disorder) may _____ in an organism, but the universe's total entropy ______ .
    decrease ; increases
  50. A living system's energy that can do work when temperature and pressure are uniform, as in a living cell
    free energy
  51. Free energy change =
    • Change in total energy (^H) MINUS Temperature in Kelvin (T) TIMES change in entropy (^S)
    • (^G) = (^H) - (T)(^S)
  52. Only processes with a ______ are spontaneous.
    negative change in free energy (-^G)
  53. a measure of a system's instability, its tendency to change to a more stable state
    Free energy
  54. During a _______, free energy increases and the stability of a system increases
    Spontaneous change
  55. a state of maximum stability is called
    Equilibrium
  56. Work can only be peformed by a spontaneous process when it is
    moving towards equilibrium
  57. Relating to free energy and metabolism, what proceeds with a net release of free energy and is spontaneous?
    exergonic reaction
  58. Relating to free energy and metabolism, what absorbs free energy from its surroundings and is NOT spontaneous?
    Endergonic reaction
  59. this powers cellular work by coupling exeronic reactions to endergonic reactions
    ATP
  60. a cell does three main kinds of work
    Chemical, Transport, and Mechanical
  61. cells manage energy resources by ________, or the use of an exergonic proces to drive an endergonic one.
    energy coupling
  62. Most energy coupling in cells is mediated by
    ATP
  63. ATP is the cells enegy shuttle and composed of
    a ribose (a sugar), adenine (nitrogenous base), and three phosphate groups
  64. The bonds between the phosphate groups of ATP's tail can be broken by
    hydrolysis
  65. Energy is released from ATP when the______________. This release of energy comes from the _____ change to a state of lower free energy, not from the phosphate bonds themsevles.
    terminal bond is broken; chemical change
  66. Three types of cellular work (mechanical, transport, and chemical) are powered by
    the hydrolysis of ATP
  67. In the cell, the energy from the exergonic reaction of ATP hydrolysis can be used to drive an
    endergonic reaction
  68. coupled reactions are
    exergonic
  69. ATP drives endergonic reactions by _________ , transferring a phosphate group to som other molecule, such as a reactant, which makes that recipient molecule phosphorylated.
    Phosphorylation
  70. ATP is a renewable resource that is regenerated by addition of a ______group to ________________.
    phosphate group; ADP
  71. The energy to phosphorylate ADP comes from ___________in the cell.
    Catabolic reactions
  72. temporarily stored in ATP and drives most cellular work
    chemical potential energy
  73. a chemical agent that speeds up a reaction WITHOUT being consumed by the reaction
    catalyst
  74. a catalytic protein
    enzyme
  75. Hydrolysis of sucrose by the enzyme sucrase is an example of
    an enzyme-catalyzed reaction
  76. The initial energy needed to start a chemical reaction is called the
    free energy of activation or activation energy (EA), which is often supplied in the form of HEAT from the surroundings
  77. Enzymes catalyze reactions by
    lowering the EA barrier
  78. Enzymes do not affect the________________; instead, they hasten reactions that would occur eventually
    change in free energy (^G)
  79. The reactant that an enzyme acts on is called
    the enzymes SUBSTRATE
  80. The enzyme binds to its substrate, forming an
    enzyme-substrate complex
  81. the region on the enzyme where the substrate binds
    active site
  82. _______ of a substrate brings chemical groups of the active site into positions that enhance their ability to catalyze the reaction.
    Induced fit
  83. The active site can lower an EA barrier by
    1
    2
    3
    4
    • Covalently bonding to the substrate
    • Orienting substrates correctly
    • Providing a favorable microenvironment
    • Straining substrate bonds
  84. non protein enzyme helpers that may be inorganic (such as a metal in ionic form) or organic
    Cofactors (these conenzymes include vitamins)
  85. bind to the active site of an enzyme, competing with the substrate
    competititve inhibitors
  86. bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective
    Noncompetitive inhibitors
  87. examples of enzyme inhibitors
    toxins, poisons, pesticides, and antibiotics
  88. this may either inhibit or stimulate an enzymes activity; it occurs when a regulatory molecule binds to a protein at one site and affects the protein's function at another site.
    allosteric regulation
  89. in allosteric activation and inhibition the binding of an activator stabilizes the________ form of the enzyme, while the binding of an inhibitor stabilizes the_______form of the enzyme.
    • active from
    • inactive form
  90. a form of allosteric regulation that can amplify enzyme activity; binding by a substrate to one active site stabilizes favorable conformational changes at all other subunits.
    Cooperativity
  91. Allosteric regulators are attractive drug candidates for enzyme regulation. Inhibition of _______ enzymes called caspases my help management of inappropriate inflammatory responses.
    proteolytic enzymes
  92. In__________,the end product of a metabolic pathway SHUTS DOWN the pathway
    feedback inhibition (most pathways)
  93. prevents a cell from wasting chemical resources by synhesizing more product that is needed
    feedback inhibition (most pathways)
  94. Some enzymes act as structural components of ________. In eukaryotic cells, some enzymes reside in specific organelles; ie, enzymes for_________ are located in mitochondria.
    • membranes
    • cellular respiration
  95. partial degradation of sugars that ocurs without O2
    fermentation
  96. Consumes organic molecules and O2 and yelds ATP
    Aerobic respiration
  97. consumes compouds other than 02
    anaerobic respiration
  98. includes both aerobic and anaerobic respiration but is often used to refer to aerobic respiration
    Cellular respiration
  99. cellular respiration equation
    C6H12O6 + 6 O2----->6 CO2 + 6 H20 + energy (~38 ATP and heat)
  100. The transfer of _____ during chemical reactions releases energy stored in organic molecules
    electrons
  101. chemical reactions that transfer electrons between reactants are called
    oxidation-reduction reactions, or redox reactions
  102. when a substance loses electrons it becomes
    oxidized as in the process of oxidation
  103. when a substance gains electrons it becomes
    • reduced as in the process of reduction (the amount of positive charge is reduced)
  104. The electron donor is called the
    reducing agent
  105. the electron acceptor is called
    the oxidizing agent
  106. What is reduced and what is oxidized during cellular respiration? What does reduced and oxidized mean?
    The glucose (C6H12O6) is oxidized (gains charge by losing electrons) and the oxygen (O2) is reduced loses charge by gaining electrons)
  107. This coenzyme and electron acceptor functions as an oxidizing agent during cellular respiration
    NAD+
  108. represents stored energy that is tapped to synthesize ATP, also passes the electrons to the electron transport chain.
    NADH (reduced form of NAD+)
  109. passes electrons in a series of steps instead of one explosive reaction
    electron transport chain
  110. pulls electrons down the electron transport chain in an energy yielding tumble and the energy yielded is used to regenerate ATP
    O2
  111. summarize the 3 stages of cellular respiration
    • 1. Glycolysis--breaks down glucose into two molecules of pyruvate (occurs in cyctosol)
    • 2. Citric Acid cycle--completes the break down of glucose in mitochondrial matrix of eukaryotes
    • 3. Oxidative phosphorylation--accounts for most of the ATP synthesis ~90% (powered by redox reactions)
  112. A smaller amount of ATP (~10%) is formed in glycolysis and the citric acid cycle by a mechanism called
    substrate-level phosphorylation
  113. Energy investment phase "Priming Phases" of glycolysis 5 steps
    Regulatory step 1

    end of 5 steps end up with two different molecules

    1.Glucose enters the cell, phosphorylated by hexokinase (stored in muscles while glucokinase stored in liver) Results in the use of 1 ATP hydrolzyed to ADP making glucose-6-phosphate


    • 2.
    • 3. 1 ATP hydrolyzed to ADP= 2 Total ATP's invested!!!
    • 4.
    • 5. At the end result is DHAP gets converted to 2 Glyceral 3 phosphates (GAP) 2 three carbon molecules!! which gets thrown into the next phase "PAY OFF" phase.

  114. 1 molecule of NADH gets converted into
    3 molecules ATP
  115. 1 FADH2 gets converted into
    2 molecules ATP
  116. Energy Payoff phase (energy liberation stage) step 6-10
    • 6. 2 NAD+ --> 2 NADH (2*3= 6 ATP)
    • 7. 2 ADP----> 2 ATP
    • 8.
    • 9.
    • 10. 2 ADP---> 2 ATP AND PYRUVATE KINASE >>>2 PYRUVATE
  117. Before the Citric acid cycle can begin, Pyruvate must be converted to acetyle CoA, which links the cycle to Glycolysis. Three steps invovled are:
    • 1. Co2 is released
    • 2. Last 2 Carbon's oxidized, NAD+ to NADH (stored energy)
    • 3. Coenzyme A (CoA) ----> added to to 2 Carbon Pyruvate to create acetyle CoA--high potential energy ready for Citric Acid cycle
  118. Citric acid cycle (krebs) oxidizes organic fuel from pyruvate, generating:
    1 ATP, 3 NADH, and 1 FADH2 per turn (must go through twice to double since glycolysis produces 2 pyruvate)
  119. Citric (Kreb's) cycle
    8 steps
    How many ATP?
    1. 2 carbon acetyl group of acetyl CoA joins the cycle by combining with oxaloacetate (4 carbon molecule), forming a Citrate (6 carbon)

    • 3.NADH
    • Loss of CO2 Isocitrate is oxidized, reducing NAD+ to
    • 4. NADH,
    • Loss of CO2
    • 5. 1 ATP produced from succinyl CoA converting to succinate
    • 6. FADH2 produced
    • 8. NADH and regeneration of oxaloacetate

    • 24 ATP produced
    • + 8 ATP Glycolysis
  120. Following the glycolysis and the citric acid cycle, ____ and ______ account for most of the energy extracted from food.
    NADH and FADH2
  121. These two electron carriers donate electrons to the electron transport chain, which powers ATP synthesis via oxidative phosphorylation
    NADH and FADH2
  122. the electron transport chain is in the
    cristae of the mitochondrion
  123. Most of the____ ____ ___ components are proteins, which exist in multi protein complexes. Some of the electrons are passed through a number of proteins including________(each with an iron atom) to O2
    • Electron Transport chain
    • Cytochromes
  124. Electrons drop in free energy as they go down the chain and are finally passed to O2, forming__1___. Electrons are transferred from__2__or__3____ to the electron transport chain. The electron transport chain DOES NOT generate___4_.
    • 1. H2O
    • 2. NADH
    • 3. FADH2
    • 4. ATP
  125. function is to break the large free-energy drop from food to O2 into smaller steps that release energy in manageable amounts.
    electron transport chain
  126. _________ in the electron transport chain causes proteins to pump H+ (protons) from the mitochondrial matrix to the intermembrane space. H+ (protons) then move back across the membrane passing through channels in_______, which uses the exergonic flow of H+ to drive phosphorylation of _ _ _.
    • electron transfer
    • ATP synthase
  127. the use of energy in a H+ gradient to drive cellular work
    Chemiosmosis
  128. The H+ (proton) gradient is referred to as a________, emphasizing its capacity to do work.
    proton-motive force
  129. The energy-coupling mechanism that couples the redox reactions of the electron transport chain to ATP synthesis
    chemiosmosis
  130. Oxidative Phosphorylation involves
    1.
    2.
    1. Electron Transport Chain--electron transport and pumping of protons (H+) which create an H+ gradient across the membrane.

    2. Chemiosmosis--ATP synthesis powered by the flow of H+ back across the membrane
  131. During cellular respiration, most energy flows in this sequence
    Glucose-->NADH-->Electron transport chain-->Proton motive force-->ATP
  132. About ____% of the energy in a glucose molecule is transferred to ATP during cellular respiration, making about___ATP
    • 40%
    • 38ATP
  133. Most cellular respiration requires____to produce ATP
    O2
  134. Glycolysis can produce ATP _____ or _______ ___ (in aerobic and anaerobic conditions)
    with or without O2
  135. In the absence of O2, __________ couples with fermentation or _________ ______ to produce ATP.
    • glycolysis
    • anaerobic respiration
  136. uses an electron transport chain wth an electron acceptor other than O2 ie sulfate
    anaerobic respiration
  137. uses phosphorylation instead of an electron transport chain to generate ATP
    Fermentation
  138. Fermentation consists of glycolysis plus reaction that regenerate_____, which can be reused by glycolysis.
    NAD+
  139. Two types of fermentation are
    • Alcohol fermentation---1. generate/release CO2
    • 2. pyruvate is converted to ethanol

    Lactic acid fermentation---pyruvate is reduced to NADH, forming lactate as an end product from pyruvate NO CO2 release
  140. Fermentation VS Aerobic Cellular Respiration
    • -Both use glycolysis to oxidize glucose etc to pyruvate
    • -Different Final electron acceptors: Fermentation uses organic molecules (like pyruvate or acetaldehyde)
    • Respiratin uses O2
    • -Cellular respiration produces 38 ATP per glucose, while Fermentation produces 2 ATP per glucose
  141. carry out fermentation or anaerobic respiration and cannot survive in the presence of O2
    Obligate Anaerobes
  142. Yeast and many bacteria can survive using either fermentation or cellular resiration because they are_____. ______ is a fork(decision is made) in the metabolic road that leads to two altenative catabolic routes.
    • facultative anaerobes
    • pyruvate
  143. Fatty acids are broken down by_______ to generate acetyle CoA > citric acid cycle > oxidative phosphorylation
    beta oxidation
  144. Sequence to produce ATP

    Proteins > 1 ( ) > 2 > 3 > 4 > 5
  145. Amino acids (deamination, NH3 biproduct) >
    • Amino goups >
    • Glycolysis or citric acid cycle >
    • Ox Phos >
    • ATP
  146. Sequence of fats to ATP
    1
    2 2
    3 3
    • Fats to (glyceral) and (fatty acids)
    • / /
    • Glycolysis------GA-3-P /
    • \ / /
    • \--------- Pruvate /
    • / /
    • acetyl CoA <----/
    • |
    • Citric Acid cycle > Oxidative Phosphorylation > ATP
  147. If ATP concentration begins to drop,__________; when there is plenty of ATP, _________.
    • respiration speeds up
    • respiration slows down (inhibition)
  148. AMP stimulates
    respiration to speed up
  149. During feedback inhibition, having enough citrate means you have enough ATP which means
    Inhibition of respiration
  150. Autotrophs sustain themsevles and dont' eat anything derived from other organsisms are called_______
    heterotrophs obtain their organic material from other organsms and are called _______
    Almost all plants are ________, using the enegy of sunlight to make organic molecules from _____ and _____.
    • producers
    • consumers
    • photoautotrophs
    • H20 and CO2
  151. Chloroplasts are structurally similar to and likely evolved from_____ ______. This is the site where ________occurs.
    • photosynthetic bacteria
    • photosynthesis
  152. CO2 enters and O2 exits the leaf through microscopic pores called
    stomata
  153. chloroplasts are found mainly in cells of the ______, the interior tissue of the leaf
    mesophyll
  154. The typical mesophyll has how many chloroplasts?
    30-40
  155. chlorophyll is in the____ of _____ (connected sacs in the chloroplast). They may be stacke in columns called?
    • membranes of thylakoids
    • grana
  156. Chloroplasts also contain_____, a dense fluid (inside inner membrane)
    Stroma
  157. Photosynthesis equation?
    6 CO2 + 6 H2O+ light energy---->C6H12O6 + 6 O2
  158. Chloroplasts split H2O into hydrogen and oxygen, incorporating the _____ of hydrogen into ______ _____.
    • electrons
    • sugar molecules
  159. Photosynthesis is a redox process in which ______ is oxidized and _____ is reduced.
    H2O is oxidized (loses electrons making it more charged) and CO2 is reduced (gaining electrons but losing charge)
  160. Two stages of Photosynthesis
    The light reactions (the photo part) and Calvin cycle (the synthesis part)
  161. The Light reactions in the ________, split _____, release___, reduce____ to _____ and then generate ____ from ____ by _________ or (___________).

    The Calvin cycle begins with _____, incorporating _____ into organic molecules.
    It happens in the________, where it forms______from ______, using ____ and _______.
    Light reactions

    • Thylakoids
    • Split H2O
    • Release 02
    • Reduce NADP+ to NADPH
    • Generate ATP from ADP by photophosphoylation (chemiosmosis)

    Calvin cycle

    • Begins wth CARBON FIXATION incorporating CO2 into organic molecules
    • Happens in the STROMA forms SUGAR from CO2 using ATP and NADPH
  162. Chloroplasts are solar-powered chemical factories that contain _____structures, which transform light energy into the chemcical energy of ____ and _____.
    • Thylakoid
    • ATP and NADPH
  163. Light is a form of ________energy, also called ________ radiation. This light travels in ____.
    • electromagnetic
    • rythmic waves
  164. Wavelength is the distance between. Wavelength determines the type of ______ ____.
    • crests of waves
    • electronmagnetic energy
  165. The________ _______ is the entire range of electromagnetic energy, or radiation.
    Electromagnetic spectrum
  166. Visible light consists of _________ (including those that drive photosynthesis) that produce colers we can see.
    Wavelengths
  167. Light asl behaves as though it consists of desgrete particles, called
    photons
  168. substances that absorb visible light.
    pigments
  169. Different _______ absorb different wavelengths. Wavelengths that are not absorbed are ____ or ______.
    • pigments
    • reflected or transmitted
  170. measures a pigments ability to absorb vairous wavelengths. Sends light through pigments and measures the fraction of light transmitted at each wavelength
    spectrophotometer
  171. a graph plotting a pigments light absorption versus wavelength
    absorption spectrum
  172. the absoption spectrum of chlorophyll a suggests that ____ and ____ light work best for photosynthesis
    violet-blue and red
  173. profiles the relative effectiveness of different wavelengths of radiation in driving a process
    action spectrum
  174. the main photosynthetic pigment
    chlorophyll a
  175. Accessory pigments, such as _____ broaden the spectrum used for photosynthesis
    Accessory pigments called _______ absorb excessive light that would damage chlorophyll
    • chlorophyll b
    • carotenoids (carotene)
  176. When a pigment absorbs light, it goes from a _______ to an_______, which is unstable
    ground to excited state
  177. When excited electrons fall back to the ground state, _______ are given off, an after glow called _______.
    • photons
    • fluorescence
  178. If illuminated, an isolated solution of chlorophyll will____, giving off ___ and ____.
    fluoresce, light and heat
  179. consists of a reaction-center complex ( a type of protein complex) surrounded by light harvesting complexes.
    Photosystem
  180. The light harvesting complexes which are ____ molecules bound to _____, funnel energy of photons to the reaction center
    pigment molecules bound to proteins
  181. A primary electron acceptor in the reaction center accepts an excited electron from __________This solar powered transfer of an electron from a _______ molecule to the primary electron acceptor is the first step of the light reactions.
    chlorophyll a
  182. two types of photosystems in the thylakoid membrane are
    • Photosystem II (PSII) functions first!
    • best at absorbing wavelengths of 680 nm

    and

    • Photosystem I (PSI) best at asborbing a wavelength of 700 nm
    • -The reaction center of chlorophyll 'a' of PSI is called P700
  183. During the light reactions, there are two possible routes for electron flow
    cyclic and linear
  184. Linear electron flow
    • Primary pathway
    • Involves both photosystems and produces ATP and NADPH using light energy
    • Releases O2
    • Electrons "fall" down an ETC from the primary electron acceptor of PSII to PSI releasing energy
  185. cyclic electron flow
    • uses only photosystem I
    • produces ATP but not NADPH
  186. Chloroplasts AND mitochondria generate_____ by chemiosmosis, but use different sources of energy.
    Chloroplasts transfrom light energy into the ____ energy of___, while the Mitochondria transfer _____energy from food to ____
    • ATP
    • CHEMICAL energy of ATP
    • CHEMICAL energy from food to ATP
  187. In chloroplasts, protons are pumped into the thylakoid space and drive ____ ___ as they diffuse back into the stroma
    atp synthesis
  188. ____ and ____ are produced on the side facing the stroma where the calvin cycle takes place.
    ATP and NADPH
  189. light reactions generate ___ and increase the potential energy of electrons by moving them from ____ to _____.
    • ATP
    • H2O to NADPH
  190. 3 phases to Calvin cycle
    how many turns?
    • 1. Carbon fixation (catalyzed by rubisco) regulatory step
    • 3 carbons come in
    • 2. Reduction- sugar formed (G3P)
    • 3. Regeneration of CO2 acceptor (RuBP)

    3 TURNS!!!
  191. Alternative mechanisms of carbon fixation in hot arid climates
    • stomata closes, conserving H2O
    • limiting photosynthesis
    • reducing access to CO2 causing O2 build up
    • (process called photorespiration) catch 22
  192. consumes O2, releases CO2 without producing ATP or sugar
    photorespiration
  193. An external signal where proteins released be certain cells stimulate other cells to divide
    growth factors
  194. stimulates the division of human fibroblast cells in culture
    platelet-derived growth factor (PDGF)
  195. an external signal in which crowded cells stop dividing
    density-dependent inhibition (contact inhibition)

    (cancer cells do not exhibit this)
  196. Most cells exhibit______ _________, in which they must be attached to a substratum in order to divide
    anchorage dependence

    (cancer do not exhibit this)
  197. angiogenesis
    formation of blood vessels
  198. A normal cell is converted to a cancerous cell by a process called
    transformation
  199. If abnormal cells remain at the orginal site, the lump is called a_________. When the ab cells invade surrounding tissues and metastasize forming secondary tumors they are called________.
    • benign tumor
    • malignant
  200. Tumor suppressor genes

    1
    2
    3
    protect or suppress cancer "tumors" off =cancer

    • 1. P53--most important
    • 2.BRCA1
    • 3.BRCA2
  201. 3 types of genes
    • 1. tumor suppressor genes- protect or suppress cancer
    • 2. proto-oncogenes "good genes" want turned on!
    • 3. oncogenes "bad genes" ON=CANCER! want off!

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