Learning Objectives 2 PDF

Learning objectives 2 Chapter 5: 1. Apply examples of cellular work and items that are not cellular work  What is cellular work o Active transport of ions across membranes o The beating of cilia or flagella to move a cell o The contraction of a muscle to walk or...

Learning objectives 2 Chapter 5: 1. Apply examples of cellular work and items that are not cellular work  What is cellular work o Active transport of ions across membranes o The beating of cilia or flagella to move a cell o The contraction of a muscle to walk or run o The manufacture of polymers from monomers o The metabolic generation of heat to stay warm o The flash of a firefly  What is NOT cellular work o Di usion of solutes in/ out of cells o The evaporation of water o The formation of hydrogen bonds o The spontaneous formation of a lipid bilayer or the folding of a protein into higher levels of structure 2. Describe and apply knowledge about the fluid mosaic bilayer lipid membrane  Membranes are composed of a bilayer of phospholipids in the fluid state  Double bond in fatty acids prevents packing  Head-groups towards surface; fatty acids inwards  Integral proteins are embedded in the membrane; peripheral proteins are loosely attached  Proteins and lipids move freely about in the membrane 3. Apply di usion, osmosis, and the factors that a ect each  Di usion- the spontaneous net movement of a substance from a region where it has a high concentration to a region where it has a low concentration OR the tendency of particles to spread out evenly in an available space o Passive o Due to random kinetic motion of molecules o Occurs down a concentration gradient o One molecule moves independently of another o Continues till equilibrium is achieved o E ected by temperature, area of di usion, molecular size, resistance of di usion medium, and distance for di usion medium  Osmosis- di usion of water across a selectively permeable membrane from a region of low solute concentration to a region of high solute concentration o E ected by osmotic pressure, concentration gradient, water potential, surface area, and temperature 4. Describe and apply three types of tonicities in both animal and plant cells  Hypotonic- solute concentration outside the cell is less than the inside of the cell; water enters the cell o In animal cells, the cell is lysed and will burst  o In plant cells, it is turgid (normal)  Isotonic- solute and water concentration inside and outside of a cell are equal; no net water movement o Is normal in animal cells o Is flaccid in plant cells  Hypertonic- solute concentration outside the cell is greater than inside the cell; water leaves the cell o Animal cells are crenated (shriveled) o Plant cells are plasmolyzed (shriveled) 5. Compare and apply active transport, exocytosis, and endocytosis  Active transport- the energy dependent transport of a substance across a biological membrane o Involves the hydrolysis of ATP and specific transport proteins o Results in transport and accumulation against a concentration gradient o Includes endocytosis and exocytosis  Exocytosis- the process by which the contents of intra-cellular vesicles are released to the outside of a cell by fusion with the plasma membrane  Endocytosis- the process by which extracellular materials are taken into the cell via the infolding of the plasma membrane and the formation of vesicles  Similarities- o Both involve vesicles and the plasma membrane o Both are essential for maintaining cellular functions and homeostasis  Di erences- o Endocytosis brings materials into the cell and is used for nutrients reuptake, immune responses, and receptor-mediated processes o Exocytosis- expels materials out of the cell and is used for secretion of hormones, neurotransmitters, and waste removal 6. Apply examples of cellular work, all definitions, theories, and laws  Cellular work- o Active transport of ions o The movement of cilia or flagella o Contraction of muscles o The manufacture of polymers from monomers o The metabolic generation of heat to stay warm o The flash of a firefly  Energy transformations- living systems function by transforming one form of energy into another  Thermodynamics- the study of energy transformations that occur in a specific collection of matter  Law of thermodynamics- rules to help explain energy transformations and flow o 1st law of thermodynamics- the total amount of energy in the universe is constant  Energy can be transformed from one form to another, but it cannot be created or destroyed o 2 law of thermodynamics- no energy transformation process is 100% e icient nd  o 3rd law of thermodynamics- the entropy of a system approaches a constant value as the temperature approaches absolute zero 7. Apply examples of potential and kinetic energy, entropy  Kinetic energy- the energy of motion o Solar / radiant energy o Heat energy o Motion energy o Sound energy  Potential energy- stored energy o Chemical energy o Nuclear energy o Electrical energy o Gravitational energy  Entropy- the measure of the randomness or disorder of a system o When ice melts into water, the structured arrangement of water molecules in the ice becomes more disordered in the liquid state, increasing entropy 8. Apply examples of exergonic, endergonic reactions and metabolism  Exergonic- (exothermic reactions) gives o energy o Products have less energy than reactants o Catabolism- breaks down molecules o Cellular respiration  Endergonic- (endothermic reactions) consumes or requires energy o Products have more energy than reactants o Anabolism- builds up molecules o Photosynthesis  Metabolism- the sum total of an organism’s reactions including both energy-releasing and energy-storing processes 9. Apply examples of ATP dependent work and the ATP cycle  ATP dependent work- ATP powers nearly all forms of cellular work by coupling exergonic and endergonic reactions. There are reactions that require ATP to operate o Chemical work- phosphorylation of reactants o Transport work- active transport o Mechanical work- muscle contraction  ATP cycle- the energy currency of the cell o Catabolic processes include the breakdown of glycogen, cellular respiration o Anabolic processes include protein synthesis, DNA replication o ATP hydrolysis is exergonic o ATP synthesis is endergonic 10. Apply examples of enzymes and their energy reactions, substrates, and products  Enzymes are… o Biological catalysts o Not consumed in the reaction o Normally proteins, sometimes RNA molecules o Very specific- can catalyze one specific reaction  oReversible- can carry out a reaction in the forward or reverse direction; brings reactions to equilibrium o Active site- the part of the enzyme where the substrate binds, and the catalytic reaction occurs o Induced fit- when a substrate enters the active site, the enzyme undergoes a slight change in shape  Enzymes in energy reactions will lower the amount of activation energy required to start the reaction  Substrate- the specific reactant that an enzyme acts on during a chemical reaction  The catalytic cycle o Enzyme available with empty active site o Substrate binds to enzyme with induced fit o Substrate is converted to products o Products are released Chapter 6: 1. Apply/ analyze definition of cellular respiration- equation of photosynthesis  Cellular respiration- the breakdown of sugars and other food molecules to carbon dioxide and water in the presence of oxygen in order to generate ATP (C6H12O6 + 6O2 -> 6CO2 +6H20)  Equation for photosynthesis- 6C02 + 6H20 -> C6H12O6 +6O2 2. Apply / analyze how plants provide energy for life  All life requires energy, and the sun is the ultimate source of energy for most ecosystems  Photosynthesis in chloroplasts convert solar energy, CO2, and H2O into chemical energy of sugars 3. Apply / analyze how cellular respiration banks energy in ATP molecules  Cellular respiration- the chemical reactions of living cells that convert the chemical energy of food molecules into ATP. In the process, O2 is consumed, and CO2 is released  Cellular respiration is exergonic; some energy is captured in the synthesis of ATP  Produces up to 32 ATP from each glucose molecule (about 34% e icient) 4. Apply / analyze how cells tap energy from electrons “falling” from organic fuels to O2  Oxidation of fuel molecules- electrons are removed from organic fuel molecules in a process called oxidation o These electrons are transferred ro a molecule called NAD+, reducing it to NADH  Electron transport chain- NADH carries the electrons to the ETC, a series of protein complexes located in the inner mitochondrial membrane o As electrons move from one carrier to another in the chain, they fall to lower energy levels, releasing energy at each step  Final electron acceptor- the electrons eventually combine with oxygen and hydrogen ions to form water  ATP production- the energy released during the electron transfer is used to pump protons across the mitochondrial membrane, creating a proton gradient  o The gradient drives the synthesis of ATP from ADP and inorganic phosphate through a process called oxidative phosphorylation 5. Apply/ analyze a ReDox reaction. Explain both. What is NADH and why is it used?  Oxidation reaction- a reaction where a substance loses electrons  Reduction reaction- a reaction where a substance gain electrons  Redox reactions always occur in pairs; there cannot be an oxidation reaction unless it is accompanied by a reduction reaction  redox reactions are normally carried out by dehydrogenase enzymes  NADH- (nicotinamide adenine dinucleotide) a water-soluble electron carrier that carries (accepts or donates) 2 electrons and 1 H+ ion o Used as an electron carrier, transfers electrons to the ETC, and facilitates energy release for ATP molecules 6. Apply the 3 main stages of cellular respiration  Glycolysis o Starts the process of cellular respiration o Occurs in the cytoplasm. Does not require oxygen o Oxidizes and cleaves a C6 glucose into two C3 pyruvates o Provides electrons in the forms of NADH to the third stage o Makes a little ATP via substrate level phosphorylation  Pyruvate oxidation and the citric acid / Kreb’s cycle o Occurs in the mitochondrial matrix o Oxidizes C3 pyruvates to C2 acetyl-CoA o Oxidizes C2 acetyl-CoA’s to CO2 o Provides electrons in the forms of NADH and FADH2 to 3rd stage  Respiratory electron transport and oxidative phosphorylation o Occurs in the cristae membranes of the mitochondria o Converts high energy electrons (in NADH and FADH2) to low energy electrons (In H2O) o Creates an energetic proton (H+ ion) gradient o Uses energy of proton gradient to make a lot of ATP via oxidative phosphorylation 7. Apply the detailed process of glycolysis  Involves… o The oxidation of glucose to 2 three carbon pyruvate molecules o The reduction of NAD+ to NADH o The synthesis of ATP via substrate level phosphorylation  Involves 9 steps or reactions o Steps 1-4 = the energy investment phase  Two ATP are used to energize glucose  Glucose split into two high energy molecules that can be used to synthesize more ATP o Steps 5-9 = the energy payo phase  Two NADH are produced per original glucose  Four ATP are produced per original glucose 8. Apply pyruvate oxidation and the Kreb’s cycle  Pyruvate oxidation to acetyl CoA is carried out by a complex of enzymes called the pyruvate dehydrogenase complex  The 8 steps of the Kreb’s cycle are a series of redox, dehydration, hydrolysis, and decarboxylation reactions that produce two carbon dioxide molecules, one GTP / ATP and reduced forms of NADH and FADH2 9. Apply the overview of the electron transport chain  High energy electrons from glucose are shuttled to the ETC via NADH  High energy electrons are gradually converted to low energy electrons via a series of redox reactions  Energy is conserved in the synthesis of ATP 10. Apply definition and terminology; net products of ALL cellular respiration 11. Apply / describe oxidative phosphorylation produces ATP  Oxidative phosphorylation- the chemi-osmotic synthesis of ATP that is coupled to the redox reactions of the mitochondrial respiratory electron transport chain during the oxidation of reduced nucleotides and the reduction of oxygen from water  Orientation- all the action occurs in the membranes bordering the intermembrane space of and cristae channels  There are four protein complexes of electron carriers embedded in the inner membranes, plus two mobile electron carriers  As electrons flow through the complexes, H+ ions are transported from the mitochondrial matrix, across the intermembrane space  The concentration of H+ ions in the intermembrane space becomes very high and the pH becomes very low  The high concentration of H+ ions represents electrochemical potential energy  The rotor of the ATP synthase acts like a “water wheel” that collapses the H+ ion gradient by forcing the return of H+ ions from the cristae channel to the matrix through the ATP synthase  The rotational energy of the rotor causes the ATP synthase active sites to synthesize ATP from ADP + Pi  Net of 36 ATP 12. Describe / apply e ects of poisons on oxidative phosphorylation  Rotenone, cyanide, CO- blocks electron transport  DNP (diet pills)- collapse the proton gradient  Oligomycin (antibiotic)- inhibits ATP synthase 13. Apply e ects of brown fat in adults  Brown fat- fat that is rich in brownish cytochrome-containing mitochondria  Active in cellular respiration  Electron transport in brown fat is naturally uncoupled with thermogenin  Specialized for heat generation  BF is correlated with lean / trim adults; absence is associated with overweight / obese adults  Activation of BF formation may be way to reduce obesity 14. Apply fermentation compare yeast to humans   In yeast, fermentation only occurs under anaerobic conditions. Oxygen must be excluded from the fermentation system or else aerobic respiration will occur w/ o alcohol production  Fermentation… o Involves only glycolysis o Yields 2 ATP / glucose o Reduces NAD+ to NADH o Recycles NADH o Ethanol or lactic acid 15. Apply history of glycolysis and cellular respiration  Cellular respiration o All stages did not always exist o Ancient earth had no oxygen o Glycolysis was the only pathway for energy production o Photosynthetic O2 production started about 2.7 billion years ago o Heterotroph endo-symbiosis- 2 billion years ago o Autotroph endo-symbiosis- 1.5 billion years ago  Glycolysis o Universally present in all organisms o Is a completely “soluble” pathway 16. Apply process- body uses organic molecules from food for cellular respiration  Carbohydrates, fats, proteins  Fats are more reduced than carbs and proteins, yield twice as much energy as proteins and carbohydrates  Approximate energy yield per gram of food fuel is o Carb- 4.2 kcal o Fats- 9.5 kcal o Proteins- 4.1 kcal  The most useful part of a nucleic acid would be the ribose, that would feed into the pentose-p pathway, and eventually be converted into glucose-6p which could enter glycolysis Chapter 7 1. Describe / apply photosynthesis fuels the trophic levels of the biosphere  Photosynthesis- the process whereby plants convert light energy and carbon dioxide into the chemical energy of sugars  Chemoautotrophs use energy sources such as hydrogen sulfide, elemental sulfur, ferrous, iron, molecular hydrogen, and ammonia (mainly bacteria and archaea)  Autotrophs- “self feeders”  Photoautotrophs- organisms that make their own food via photosynthesis  Chemoautotrophs- prokaryotic self-feeders that make their own food using inorganic chemicals as their source of energy  Heterotrophs- other feeders; feed on plants, animals, or decompose organic matter as a source of food  Herbivores and carnivores  Saprotrophs- specifically consume non-living matter 2. Apply leaf anatomy, trace redox reactions photosynthesis  Leaves are the main photosynthetic organs of plants  Stems can be modified to perform photosynthesis  Carbon dioxide becomes reduced to C6H12O6  Water oxidizes to oxygen 3. Apply the two chemical stages of photosynthesis  Stage 1- with sunlight irradiation moving into the chloroplast hitting the photosystems, water coming into the light reactions in the thylakoids, and oxygen gas is produced o Light energy is absorbed by chlorophyll o Water molecules are split o Electrons are transferred o A transmembrane H+ gradient is created o ATP is synthesized  Stage 2- adding on to the light reactions, are the dark reactions in the Calvin cycle, located in the stroma of the chloroplast o CO2 is fixed and reduced; sugars are synthesized o ATP and NADPH are consumed 4. Apply photosynthetic pigments light reactions and absorption  Electromagnetic radiation- main form of energy emitted by the sun o Travels in waves of di erent lengths and units of energy called photons  A continuous spectrum of wavelengths exist  Only a small portion of the spectrum is visible  Chlorophyll b has a aldehyde group in ring 2  Carotenoids are often referred to as accessory pigments that help photosynthesis in two ways o Extending the useful range of light into blues o Antioxidant to protect the chloroplast from reactive oxygen species 5. Apply how photosystems capture and absorb light and transfer energy  Photosystem- a collection of light harvesting complexes comprised of pigment molecules bound to proteins, all embedded in the thylakoid membrane  Light absorption raises an electron to a higher energy orbital  Return to ground state releases light energy 6. Apply and describe photosystems II and I with electron transport chain  A light harvesting pigment molecule absorbs a photon of light and becomes energized. Energized condition is gradually transferred to the reaction center  The energized electron is captured by the primary receptor  A water molecule is split into electrons, H+ ions and O2; electrons released replace those lost by the reaction centers  Energized electrons from the primary acceptor of PSII are transferred to PSI to replace those lost by reaction centers; in the process, a proton gradient is created   Pigment molecules of PSII absorb photos and become energized as for PSI, and resonance energy transfer occurs. Energized electrons are captured by primary acceptor of PSI  Energized electrons of PSI are transferred to NADP+ via a short term electron transport chain 7. Apply and describe the light reactions in the thylakoid membranes and photophosphorylation and poisons a ecting this process  A light harvesting pigment molecule absorbs a photon of light and becomes energized. Energized condition is gradually transferred to the reaction center  The energized electron is captured by the primary receptor  A water molecule is split into electrons, H+ ions and O2; electrons released replace those lost by the reaction centers  Energized electrons from the primary acceptor of PSII are transferred to PSI to replace those lost by reaction centers; in the process, a proton gradient is created  Pigment molecules of PSII absorb photos and become energized as for PSI, and resonance energy transfer occurs. Energized electrons are captured by primary acceptor of PSI  Energized electrons of PSI are transferred to NADP+ via a short term electron transport chain  Herbicides work by blocking PS electron transport 8. Apply and describe the dark reactions in the Calvin cycle creating sugars  Carbon fixation  Carbon reduction  Synthesis and release of 1 G3P  Regeneration of RuBP “sugar” product in chloroplast is a triose  Trioses are exported and used to synthesize hexoses 9. Apply and describe the summary reactions for photosynthesis  Light reactions o 6H20 + 9ADP+Pi +6NADP+ -> 12H+ + 12e- +3O2  Dark reactions o 3CO2 + 9ATP + 6NADPH -> C3H6O3 + 3H20 + 9ADP+Pi + 6NADPH+ 10. Apply and describe the problem with rubisco in C3 plants  Sometimes rubisco reacts with oxygen instead of CO2 o Occurs in the light o Consumes oxygen o Releases carbon dioxide o Uses ATP o Does not produce sugar o Depends on amounts of CO2 vs. O2 o Is a major ine iciency in PS 11. Apply and describe factors that a ect CO2 availability  Normal C3 photosynthesis can quickly deplete CO2 in the air  Water stress causes stomatal closure, reducing both the entry of CO2 into and the escape of O2 out of the leaves 12. Apply and describe carbon fixation in C4 and CAM photosynthesis  C4 o Discovered in tropical plants like sugar cane o First intermediate as a C4 acid o C4 plans have a distinct leaf anatomy o C4 plants have a very high photosynthetic e iciency  CAM o Crassulacean Acid Metabolism o Discovered in the Crassulaceae plant family o Adapted to live in hot dry environments o CAM plants have a very high water use e iciency 13. Apply and describe leaf anatomy details and importance, examples of C4 photosynthesis  CO2 is pumped from mesophyll cells to bundle sheath cells  CO2 levels in bundle sheath become much higher than oxygen  Bundle sheath Rubisco only fixes CO2  C4 plants have no photorespiration  C4 plants grow faster than C3 plants  Plants can partially close stomata and still obtain su icient CO2  Especially important in hot environments  Sugar cane 14. Apply and describe details, importance, and examples of CAM photosynthesis and plants  CO2 is fixed at night by PEP carboxylase  A C4 acid is stored in the vacuole until the next day  Next day, stomates close; malate is retrieved and decarboxylated to release CO2  Released CO2 is used by the Calvin cycle  Plants use and lose much less water  Cacti and aloe vera 15. Apply and describe summary of C3, C4, and CAM climate / environment adaptations and characteristics  C3 plants o Temperate climates (moderate sunlight, rain, temperature) o PS opt. = 15-20 C o Moderate water use e iciency o Moderate productivity  C4 o Tropical climates (high sunlight, temperature, rain) o PS opt- 30-47 C o High water use e iciency o Very high productivity  CAM o Desert climates (very hot, dry, and bright) o PS opt- 30-35 C o Extremely high water use e iciency o Very low productivity