Graphing Tuesday Create a line graph with 2 y axes. These are fake numbers @ hunting in Summer Shade! Year# Hunters 2000150 2001200 2002125 2003100 2004300 2005350 2006355 Year# Deer 20008,000 20017,800 20023,000 20032,500 20043,000 20053,250 20064,500
Stem Cell Review 1. What is a stem cell? _____________ ________ 2. List the 2 types of stem cell: ______ ________ 3. Which stem cell is controversial? Why? 4. Where do they get adult stem cells from?
Review Potential vs. Kinetic Energy List 4 macromolecule types How are these made/destroyed? Functions of Each Macromolecule.
Metabolism The sum of all chemical reactions occurring in an organism. Catabolism- breaking down. EXERGONIC. Releases stored potential energy/heat. Anabolism- building up. ENDERGONIC. Absorbs energy/heat from environment. Anabolism and Catabolism are an example of ENERGY COUPLING…2 different processes united by common energy.
Energy (E) Kinetic- energy of movement, usually e- or protons in Biology. Potential- energy of position, usually in the chemical bonds of e-/p in Biology. Cell Respiration releases energy (KE), Photosynthesis allows capture of E from great E source (PE)
Thermodynamics Study of heat and its properties. First Law of Thermodynamics: energy cannot be created/destroyed just transformed/transferred. Second Law of Thermodynamics: every energy transfer increases entropy (disorder). Most organized at conception, as you move towards death you become more organized…evolution?
LE 8-3 Chemical energy Heat CO 2 First law of thermodynamicsSecond law of thermodynamics H2OH2O Sunlight is high quality E, Heat is low quality E
Gibbs “Free” Energy- ability to work (make ATP/GTP) Δ G = ΔH – TΔ S G- Gibbs “free” energy H – Enthalpy (Total usable energy in the system) T – Temperature in Kelvin (273 + C ⁰ ) S- Entropy (Disorder created by something being broken down) Δ – Change in a variable over time
Unstable (Capable of work)=LIVING vs. Stable (no work)=DEAD G = 0 A closed hydroelectric system G < 0
LE 8-6a Reactants Energy Products Progress of the reaction Amount of energy released ( G < 0) Final-initial E Free energy Exergonic reaction: energy released Catabolism if G is negative, e.g. cell respiration. There is free energy to do work
LE 8-6b Reactants Energy Products Progress of the reaction Amount of energy required ( G > 0) Free energy Endergonic reaction: energy required Anabolism if G is positive, then it cannot do work, energy is bound up (photosynthesis=endergonic)
Remember Not all energy can be used… Lots is lost to heat, some to waste (defacation)
Types of work performed by living cells NH 2 Glu P i P i P i P i NH 3 P P P ATP ADP Motor protein Mechanical work: ATP phosphorylates motor proteins Protein moved Membrane protein Solute Transport work: ATP phosphorylates transport proteins Solute transported Chemical work: ATP phosphorylates key reactants Reactants: Glutamic acid and ammonia Product (glutamine) made + + +
Enzyme Review Protein function is caused by structure…sequence of _ _ and how they are _. All major processes in cells involve proteins. Suffix of most proteins:_ Proteins are catalysts: speed up and control rate of reactions.
Enzyme Review Enzymes are not consumed in the reaction. Benefit? Enzymes used to be described as “lock and key” now they are said to be “induced fit” or “fits like a glove” H bonds responsible for induced fit
Enzymes Lower E A Energy of Activation is the energy required to get the molecules lined up and ready for a reaction to take place (metabolism). Because the molecules are sitting in the enzyme in position, it reduces all the time and energy of them “naturally” coming together. Enzymes also eliminate the need for heat to move the molecules faster…we won’t incinerate ourselves during metabolism
. Course of reaction without enzyme E A without enzyme G is unaffected by enzyme Progress of the reaction Free energy E A with enzyme is lower Course of reaction with enzyme Reactants Products
. Substrate Active site Enzyme Enzyme-substrate complex
Enzymatic Process Active Site- location of chemical reactions between enzyme and substrate. Enzyme Substrate Complex- caused by induced fit. Held together by H bonds, ionic bonds, and Van der Waals. The amino acid R groups perform the reaction.
. Enzyme-substrate complex Substrates Enzyme Products Substrates enter active site; enzyme changes shape so its active site embraces the substrates (induced fit). Substrates held in active site by weak interactions, such as hydrogen bonds and ionic bonds. Active site (and R groups of its amino acids) can lower E A and speed up a reaction by acting as a template for substrate orientation, stressing the substrates and stabilizing the transition state, providing a favorable microenvironment, participating directly in the catalytic reaction. Substrates are converted into products. Products are released. Active site is available for two new substrate molecules.
3 Factors that Affect Enzymes 1. Temperature 2. Salinity 3.pH *They all affect the 2*structure of proteins by altering the H bonds. If a protein unwinds it is said to be __ Type of protein that prevents misfolding_
Enzyme Inhibitors These will slow or stop the rate of reactions 1. Competitive Inhibitors- compete with substrate for active site, bind to active site, and SLOW reactions down. 2. Non-competitive Inhibitors- bind somewhere to the enzyme, change the active site completely, and STOP reactions. Inhibitors can be classified as reversible (Antabuse) or irreversible (Sarin-nerve gas)
. Substrate Active site Enzyme Competitive inhibitor Normal binding Competitive inhibition Noncompetitive inhibitor Noncompetitive inhibition A substrate can bind normally to the active site of an enzyme. A competitive inhibitor mimics the substrate, competing for the active site. A noncompetitive inhibitor binds to the enzyme away from the active site, altering the conformation of the enzyme so that its active site no longer functions.
Allosteric Enzymes “Allo” different, “stery” shape Enzymes that will change shape, thus being turned off or on. Inhibitor molecules turn the enzyme off Feedback Inhibition or Negative Feedback Loop-prevents wasting energy Activator molecules turn the enzyme on
Feedback Inhibition or Negative Feedback Active site available Initial substrate (threonine) Threonine in active site Enzyme 1 (threonine deaminase) Enzyme 2 Intermediate A Isoleucine used up by cell Feedback inhibition Active site of enzyme 1 can’t bind theonine pathway off Isoleucine binds to allosteric site Enzyme 3 Intermediate B Enzyme 4 Intermediate C Enzyme 5 Intermediate D End product (isoleucine)
Cooperativity One active site helps other active sites on the same molecule. RBC-4 part molecule, each part carries O. When Part 1 fills with O the next part does …and RBC deliveer O in the same way. This is an example of cell efficiency/specializatino, conservation of E, and regulation.
Proteins involved in constructing a red blood cell Quaternary Structure Chains Chains Hemoglobin Iron Heme Collagen Polypeptide chain Polypeptide chain
Bioenergetics Enzymes are needed in all efficient energy reactions. Two energy reactions we will focus on: Photosynthesis- anabolic, endergonic, +G Cell Respiration-catabolic, exergonic, -G
Remember Electrons are a source of E CHOs come from H 2 0 and CO 2 by plant’s chloroplast E in a molecule is directly related to # H present. Autotrophs = Heterotrophs =
Photosynthesis Chlorophyll- light absorbing protein pigment that reflects green light. Found in plants, algae, and blue-green bacteria. Chloroplast- organelle that contains grana (thylakoids) and stroma
Chloroplast Parts Thylakoids- contain chlorophyll. Site of Light reaction. Purpose is to make ATP & NADPH. Grana- stacks of thylakoids Stroma- watery area @ thylakoids. Site of light independent (Calvin Cycle). Purpose is to use ATP & NADPH to make glucose using CO 2
Photosynthesis chemical reaction (Remember… conservation of matter.) 6 CO2 + 6 H2O C6H12O6 + 6 O2 + Heat
Photosynthesis Take radiant energy and convert into chemical energy (ATP & NADPH) Take chemical energy (ATP & NADPH) and turn it into potential chemical energy (carbohydrate). Sugar creation is done by catabolism.
Sunlight High quality E Sunlight travels in waves. Each color has a wavelength Red light has the longest wavelengths Least energy of the white light Blue light has the shortest wavelengths Most energy of the white Units of light are called photons
Chloroplasts REFLECTING Green Light White light Refracting prism Chlorophyll solution Photoelectric tube Galvanometer The high transmittance (low absorption) reading indicates that chlorophyll absorbs very little green light. Green light Slit moves to pass light of selected wavelength 0 100
Chlorophyll ABSORBING Blue light to power photosynthesis White light Refracting prism Chlorophyll solution Photoelectric tube The low transmittance (high absorption) reading indicates that chlorophyll absorbs most blue light. Blue light Slit moves to pass light of selected wavelength 0 100
Chloroplasts absorbing the blue and the red light waves. The green is NOT being absorbed.
Light Absorption vs. Reflection Absorbed light = used light (red and blue0 Reflected light- unused light (green light) in plants
Chlorophyll Molecule (How many electrons are in Mg’s outer shell?) Hint: Look at the Periodic Table.
Absorbed Light Light is absorbed by pigments: Chlorophyll A-main one Chlorophyll B- help A Carotenoids- reflects orange, red, yellow, help A Photosystems- groups of pigments in the thylakoid membrane Photosystem I: makes ATP & NADPH Photosystem II: makes ATP
Synthesis Question (U2, D6) Question: The word “photosynthesis” means the “the process of using light to make”. What is made in the process is the organic macromolecule sugar (carbohydrate). In no more than three sentences, justify the meaning of photosynthesis by briefly telling what colors of light are involved in the process, what the light is converted into, and what are those molecules purpose. (5 Points)
1pt. Discussion of the red and blue colors of white light being absorbed by plants. 1pt. Discussion of converting the light energy into ATP and NADPH or chemical energy molecules 1pt. Discussion of ATP and NADPH (Chemical energy molecules) being used to make sugar. 1pt. Correct use of scientific terms. 1pt. Answer has no more than three sentences. (Following Directions.)
Remember Cells have a high SA:V ratio. Why? SA:V ratio also high for mitochondria and chloroplast. Valence electrons involved in bonding.
Light Dependent Reactions of Photosynthesis * Turns radiant energy into chemical energy __ & __. Takes place in the light, on thylakoid membrane. Uses photosystems either in a cyclic electron flow or a non-cyclic electron flow. There are 1000s of photosystems per each thylakoid. Benefit? SA:V?
Photosynthesis 1. Sunlight strikes the Photosystem II, 2 H2O enters Photosystem II. 2. O2 is released from PII as waste, and 2H+, 2 E- are left. 3. H+ is in the stroma, and the e- move using a carrier protein, Cytochrome C, down the primary electron transport chain.
4. Light also strikes Photosystem I causing it to lose electrons and move down another primary electron transport chain. 5. e-from PI, move towards enzyme, to NADP+ Reductase this enzyme reduces NADP+ into NADPH. Redox Reactions- 2 molecules exchanging e- 6. Redox reactions cause e- to move down ETC
7. As e- move down the ETC, they power proton pumps (H+) with their kinetic energy. 8. H+ actively pumped from stroma into the thylakoid which causes a change in pH, and the concentration gradient is established. (air in balloon) 9. This [gradient] is the potential energy that will make ATP using the enzyme ATP Synthetase Complex (complex=many proteins) through anabolic phosphorylation. (air leaving balloon)
The quantities are mind boggling. A hectare (e.g. a field 100 m by 100 m) of wheat can convert as much as 10,000 kg of carbon from carbon dioxide into the carbon of sugar in a year, giving a total yield of 25,000 kg of sugar per year. There is a total of 7000 x 10 9 tonnes of carbon dioxide in the atmosphere and photosynthesis fixes 100 x 10 9 tonnes per year. So 15% of the total carbon dioxide in the atmosphere moves into photosynthetic organisms each year.
H+ (protons) being pumped into the thylakoid to “build” potential energy. Photosynthesis Photosynthesis
Energy Coupling Using energy from the proton pump to make energy in the form of ATP. Active transport sets up [gradient], diffusion creates the ATP Making ATP in photosynthesis is called chemiosmosis.
Remember 1. Law of Conservation of Mass- Matter is neither created or destroyed…just transferred/ transformed. CHO are energy storage molecules for quick release. C is the backbone of the 4 biomolecules. Primary source of C is CO 2 from air.
Light Independent Reactions- Calvin Cycle Uses ATP and NADPH to perform carbon fixation (make sugar from CO 2 ). 1. CO 2 enters through the stomata, CO 2 diffuses through c.m. and membrane of chloroplast into the stroma. 2. 3CO 2 molecules will be added to RuBP- a five carbon molecule. 3. Immediately the 6C molecule breaks into 2 3C molecules (6 3C molecules total).
4. Use 6 ATP & 6 NADPH to bend each 3C sugars. (6 3C sugars). The bent 3C sugars are then 6 molecules of G3P.
5. 1G3P goes into making glucose, the other 5 G3Ps go back into the Calvin Cycle. 6. Using 3 ATP they are converted into 3 molecules of RuBP
Making Glucose One G3P per turn of the cycle. Takes 2 turns to make one glucose. Takes 9 ATP and 6NADPH per turn… 18 ATP and 12 NADPH per glucose. The glucose is used for food, and excessis stored in starch to be used in cell respiration or making cell walls.
Photorespiration Uses O 2 to fix carbon instead of CO 2. This is a last resort to stay alive, when the stomata are closed off to prevent H 2 0 loss. In C3 plants this will quickly lead to death. In C4 plants there is extra enzymes to grab CO2, and photosynthesis occurs in the inner leaf cells. These plants are adapted for hot weather…corn, cotton, summer flowers.
CAM Plants Crussulacean Acid Metabolism- utilize CO 2 stored as Crussulacean Acid because stomata only open at night. The C. acid is broken down in the day, and releases CO 2 for Calvin Cycle. Desert plants, succulents, bromeliads, etc. CAM Plants prevent transpiration.
Transpiration Transpiration dictates available energy… Deserts have lots of transpiration …minimal photosynthesis…minimal E. Rainforests have little transpiration…lots of photosynthesis…lots of E…bigger food webs.
Competition vs. Evolution Each plant type (C3, C4, CAM) have its own niche. A niche prevents competition thus conserving E. The more E conserved the more spent of reproducing, thus highly populating the area. Is this competition or evolution? Justify in 3 sentences.
Remember… Law of Conservation of Matter… Second Law of Thermodynamics- all E initiates from the sun (high quality), and ends up in entropy (low quality/disorder). Carbon skeletons for 4 biomolecules
Energy Flow and Matter Cycling Microorganisms and other detritivores Tertiary consumers Secondary consumers Detritus Primary consumers Sun Primary producers Heat Key Chemical cycling Energy flow
Carbon Cycle Cellular respiration Burning of fossil fuels and wood Carbon compounds in water Photosynthesis Primary consumers Higher-level consumers Detritus Decomposition CO 2 in atmosphere 1.All C starts in atm. 2.Photosynthesis fixes CO2 to sugar. 3.Sugars used by consumers in cell respiration and release CO2. 4.Fossil fuel burning also releases CO2 into atm.
Ecosystems All the interacting communities is a given area, also involves abiotic factors. Important Abiotic factors: Temp. Water Nutrient cycling Energy flow
Trophic Structure “troph=feed” These are feeding relationships. Second Law- with each level E is lost to entropy. All E eventually lost to heat. Matter also flows through the trophic levels, never created/ destroyed…think geochemical cycles
Energetic Hypothesis/ Pyramid of Numbers Energetics Hypothesis- there are short food chains because of the 10% rule. 90% of all energy consumed by the organisms is lost to heat/ maintenance before eaten by the next trophic level.
10% Rule Growth (new biomass) Cellular respiration Feces 100 J 33 J 67 J 200 J Plant material eaten by caterpillar
Primary Productivity Total amount of sunlight turned into chemical energy by photosynthesis. Global Energy Budget- amount of sunlight used for photosynthesis. Photosynthesis produces 170 billion tons of sugar annually. Using only 1% of solar energy.
Productivity of the Earth (Based on Chlorophyll Density) Red And Yellow areas have the highest productivity…so where are they located?
Net Primary Productivity Gross Primary Productivity- total E produced R- E used by autotrophs NPP usually = 10%. It is the E available to next trophic level. NPP = GPP - R