Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
BIOLOGY___NOTES_Chapters 8 and 9-Photosynthesis and Cellular Respiration PHOTOSYNTHESIS-Chapter 8 I. Energy = ability to do work A. Autotrophs and Heterotrophs – Originally most all energy comes from ________ • Plants and some other organisms use the sun’s energy to produce____________. • ________________make their own food. • _________________obtain energy from food they consumer • Some obtain energy as decomposers B. Chemical Energy and ATP • When electrons in bonds are shifted from higher to lower energy levels,_______________is released as heat and light • ___________________is one of the principal chemical compounds used to store and release energy The 3 Phosphate groups are the key to ATP’s ability to store and release energy 1 • 1)_______________________is a compound that looks a lot like ATP,except it has 2 phosphate groups and this difference is the key to storing energy.When a cell has energy available it can store small amounts by adding a phosphate to ADP,making ATP (think of ATP like a fully charged battery) • 2)Releasing Energy---Energy stored in ATP is released by breaking the bond between the 2nd and 3rd phosphates,releasing energy as needed.This can power such things as _______________across the membrane of the cell,protein synthesis and muscle contraction ---ATP is exceptionally useful as the _____________________________. C.Using Biochemical Energy– For active transport---________________________________________________ ______________________that pumps Na+ out of cell and K+ into the cell.ATP keeps the pump working and keep ions balanced – ATP powers synthesis of proteins,__________________ and responses to _______________________________________ – . Cells only have a small amount of ATP,to last seconds…..not good for long term storage(1 molecule glucose stores 90 x the chemical energy of ATP).Cells can regenerate ATP from ADP as needed by the energy in foods like glucose II.PHOTOSYNTHESI-AN OVERVIEW – Plants use the energy of sunlight to convert water and CO2 into sugars and starches,as well as O2 a.Investigating PHOTOSYNTHESIS – Centuries ago the simple question was did the increase in tree’s mass come from soil,water or air? – 1) Van Helmont’s Experiment2 – 1600’s-Belgian physician did an experiment to see if the soil caused plants to grow,by trying to grow w/o soil….he concluded most of the gain in mass was from water…..this accounts for ½ the products of photosynthesis. 2)Preistly’s Experiment – Candle w/jar over it-concluded that air enabled it to burn – He put a sprig of a plant under the jar and waited a few days,…The candle could burn briefly under the jar…So he concluded the plant ________________________ 3)Jan Ingenhoutz • showed the plant produced oxygen only if exposed to light » In conclusion to all 3 experiments,it is concluded that plants exposed to CO2 and light and water,produce O2 and carb’s B. The Photosynthesis Equation light • 6 CO2 + 6 H2O--- C6H12O6 + O2 Plants use the sugars to produce complex carb’s such as _______ 3 C.Light and Pigments • • Photosynthesis also requires light and Chlorophyll (found in Chloroplasts) White light is a mixture of different wavelengths of light---seen as ____________________ • Plants gather the sun’s energy with light absorbing molecules called_____________________. • The principal plant pigment is__________________.-chlorophyll a and b • Chlorophyll absorbs light well in the blue-violet and red regions,but not well in the _______________region,which is reflected by leaves • Contain red and orange pigments like _________________,that absorb light in other regions • When chlorophyll absorbs light,much of the energy is transferred directly to electrons in Chlorophyll ,raising _________________________-which make photosynthesis work!!! 4 Chapter 8 Photosynthesis Notes III. The Reactions of Photosynthesis A. Inside a Chloroplast Photosynthesis takes place in the ______________________________. The chloroplasts contain saclike membranes called _______________________________ which are arranged in stacks known as ________________ Proteins in the Thylakoids membrane organize chlorophyll and other pigments into clusters known as _____________________________These are the light –collecting units of the chloroplast Light dependent reaction happens in __________________________________________________________. 5 Light-independent (Calvin-cycle) reaction happens in _______________________________-region outside thylakoid membranes Figure 8-7 Photosynthesis: An Overview Section 8-3 Light CO2 Chloroplast Chloroplast NADP+ ADP + P LightDependent Reactions Calvin Cycle ATP NADPH O2 Sugars Go to Section: B. Electron Carriers When sunlight excites electrons in chlorophyll ,the electrons gain a great deal of energy…..They require a carrier--_____________________________________________________________________ _____________________________________________________________________ ________________by electron transport chain _________nicotinamide adenine dinucleotide phosphate-accepts 2 high energy electrons along w/ a H+,converting it into _________.This is one way some of the energy of sunlight is trapped in chemical form ____________________________________________________-then becomes an electron carrier C. Light –Dependent Reactions Require light Light is used to produce ATP and NADPH 6 Figure 8-10 Light-Dependent Reactions Section 8-3 Photosystem II Hydrogen Ion Movement Chloroplast ATP synthase Inner Thylakoid Space Thylakoid Membrane Stroma Electron Transport Chain Photosystem I ATP Formation Go to Section: 1. Photosynthesis begins when pigments in photosystem II absorb light.Energy is absorbed by high energy electrons and passed on to electron transport chain.new electrons come from the water,and O2 is released into air 2. High –energy electrons move from electron transport chain from photosystem II to photosystem I.Energy from electrons is used by molecules in electron transport chain to transport H+ ions from stroma into the inner thylakoid space. 3. Pigments in _______________________________ use energy from light to regenerate electrons.NADP+ picks up high energy electrons,along w/ H+ ions,at outer surface of thylakoid membrane…+ H+ ion=NADPH 4. As electrons pass from chlorophyll to NADP+,more________________are pumped along the membrane….Eventually ,the inside of the membrane fills w/ H+ ions……outside of membrane is _______________________charged…The difference in charges produces energy for ATP….This is why H+ ions are so important. 5. H+ ions cannot cross membrane directly…..But, the membrane contains a protein called __________________________ that goes across the membrane and allows H+ ions to pass through it.As H+ passes through, ATP synthase,the protein rotates,binding w/ ADP and a phosphate group to make_________________ So….. light-dependent part makes high energy electrons and also ATP. 7 D. The Calvin Cycle o The ATP and NADPH from light-dependent part are not stable enough to store energy for more than a few moments….these are used in _____________________________to make high energy compounds that can last a long time----it makes ________________. o o o Does not require light so is called _________________________________ Figure 8-11 Calvin Cycle Section 8-3 CO2 Enters the Cycle Energy Input ChloropIast 5-Carbon Molecules Regenerated 6-Carbon Sugar Produced Sugars and other compounds Go to Section: 1) 6 CO2 molecules enter from the atmosphere .They combine w/ 6 ___________________________________.The result is 12 3-C molecules. 2) 12 3-C molecules convert to higher energy forms….The energy for this comes from ATP and ________________________________________. 3) 2 3-C molecules removed from cycle…these are used to produce__________________________________________________ ___________________________needed for plant metabolism and growth. 4) Remaining 10 3-C are converted back into 6 5-C molecules.They combine w/ 6 new CO2 molecules to begin cycle again. 2 sets of photosynthetic reactions work together-lightdependent traps energy of sunlight in ____________form and light –independent reactions(Calvin Cycle) use that chemical 8 energy to produce stable,high energy sugars from CO2 and water….also O2 is produced. E. Factors affecting Photosynthesis Water supply Temperature---affects enzymes Light intensity----it does reach a maximum-or optimal level of light,depending on plant type--eg.conifers only photosynthesize on __________________________. Chapter 9-Cellular Respiration/Notes I.Chemical Pathways ➪ Food serves as a source of raw materials for molecular synthesis and energy A. Chemical Energy and Food ➪ 1 g glucose when burned in the presence of O2 releases 3811 calories of heat energy. ➪ A _______________is the amount of energy needed to raise the temperature of 1 g water 1 degree C. ➪ The calorie used on food labels is a kilocalorie,or 1000 calories ➪ Cells don’t “burn” glucose.Instead,they gradually release the energy from glucose and other food compounds. ➪ Begins w/ __________________________-a pathway that releases a small amount of energy.If O2 is present,it turns to 2 other pathways that release a lot of energy and if O2 is not present,glycolysis is followed by another pathway. 9 Chemical Pathways Section 9-1 Glucose Glycolysis Krebs cycle Fermentation (without oxygen) Electron transport Alcohol or lactic acid Go to Section: ➪ Final steps of cellular respiration takes place in the _________________ B. Overview of Cellular Respiaration ➪ In the presence of O2,Glycolysis is followed by the Krebs cycle and the electron transport chain ➪ Glycolysis,electron transport chain and Kreb’s cycle make up_________________________________-the process that releases energy by breaking down glucose and other food in the presence of O2 ➪ Glycolysis equation______________________________________________________ ➪ Requires O2 ,food and gives off CO2 ,water and energy ➪ The cell has to find a way trap these little bits of energy to make ATP. 10 Figure 9–2 Respiration: An Overview Section 9-1 Mitochondrion Electrons carried in NADH Pyruvic acid Glucose Glycolysis Krebs Cycle Electrons carried in NADH and FADH2 Electron Transport Chain Mitochondrion Cytoplasm Go to Section: C. Glycolysis= process in which one molecule of glucose is broken in ½ ,producing 2 molecules of __________________________,a 3-C compound Figure 9–3 Glycolysis Section 9-1 Glucose 2 Pyruvic acid To the electron transport chain Go to Section: 1. ATP Production ➪ 2 molecules of _____ used @ beginning/4 molecules ATP are produced @ end-net gain of 2 molecules 2. NADH Production ➪ 4 high energy molecules are removed and passed onto electron carrier _____________-nictotinamide adenine dinucleotide-these accept a pair of high energy electrons making ________________ and it passes electrons onto next molecule.Energy is passed from glucose to other pathways. 11 ➪ Process is fast so ATP is produced –a lot in a short amount of time. ➪ Does not require O2 ➪ A problem:when a lot of ATP is made from glycolysis-NAD+ fills w/electrons and w/o NAD+,glycolysis stops D. Fermentation ➪ Follows glycolysis if O2 is not present ➪ _________________________releases energy from food molecules by making ATP in the Absence of O2. ➪ Cells convert NADH to NAD+ by passing electrons to _____________acid.This coverts NADH back to carrier NAD+,allowing glycolysis to continue ➪ Called__________________because it does not require O2. 1) Alcoholic Fermentation ➪ Used by______________________________________ ➪ Ethyl alcohol and CO2 are made as waste Pyruvic acid + NADH-- alcohol + CO2 + NAD+ ➪ Causes bread dough to rise due to _____ 2) Lactic Acid Fermentation ➪ Fermentation that uses pyruvic acid produced to convert to lactic acid ➪ Regenerates NAD+ so glycolysis can continue ➪ Pyruvic acid + NADH-- lactic acid + NAD+ ➪ Produced in muscles during rapid exercise when the body cannot supply enough ___ to the tissues.(for ATP production) ➪ Causes a painful burning sensation ➪ Unicellular organisms also produce lactic acid as a waste during fermentation…..eg .prokaryotes in yogurt production,buttermilk,sauerkraut… 12 Figure 9–4 Lactic Acid Fermentation Section 9-1 Glucose Pyruvic acid Lactic acid Go to Section: • • • – – – – – – – II. The Kreb’s Cycle and Electron Transport At the end of Glycolysis,90 % of chemical energy available in glucose is still unused,locked in high energy electrons of ____________________ O2 becomes a powerful electron acceptor Called ______________because these pathways require O2 A. The Kreb’s Cycle – During the Kreb’s Cycle,pyruvic acid is broken down into ______ in a series of energy-extracting steps Because ________________is the 1st compound formed,it is also called ___________________. – 1) Begins when pyruvic acid produced by glycolysis enters the _________________. – 1 C-atom pyruvic acid becomes part of CO2 and gets released into the air. – 2) Citric acid is broken down into a 4-C molecule,more CO2 is released,and _________________are transferred to energy carriers For each turn of the cycle,a molecule similar to ADP is converted into a molecule similar to ATP. Electron carrier NAD+ changes to ____________ Electron carrier FAD(flavine adenine dinucleotide) changes to _________________ What happens to each of the Kreb’s Cycle Products? CO2 released is the source of all CO2 you exhale __________produced directly can be used for cellular activities 13 – • • • • • • In the presence of O2,high-energy electrons from electron carriers are used to make large amounts of ATP Kreb’s Cycle B.Electron transport • Kreb’s Cycle produces high-energy electrons passed to NADH and FADH2 These electrons are passed from the electron carriers to _______________________,which uses high energy electrons from Kreb’s cycle to convert ADP into ATP 1)High energy electrons are passed from NADH and FADH2 are passed along electron transport chain In eukaryotes,the chain is composed of carrier proteins in the inner membrane of the mitochondrion. In prokaryotes,the same chain is in the ____________________ At the end of the chain,an enzyme combines these electrons w/H+ ions and O2 to form __________ O2,then ,serves as the final electron acceptor of the electron transport chain,getting rid of wastes(low energy electrons and H+ ions.) 2) Every time 2 high energy electrons transport down the transport chain,their energy is used to transport H+ across the membrane…..H+ ions build up in the intermembrane space making it positive…. and the other side is negative. 14 • 3) How does the cell use the charge difference?....The inner membranes of mitochondria contain protein spheres called ATP synthase….As H+ ions escape into the proteins,the enzyme rotates,adding phosphate to low energy ADP to make _____. On the average,each pair of high energy electrons moves down the chain,providing enough energy to make 3 ATP from 3 ADP. Section 9-2 Figure 9–7 Electron Transport Chain Electron Transport Hydrogen Ion Movement Channel Mitochondrion Intermembrane Space ATP synthase Inner Membrane Matrix ATP Production Go to Section: C) THE TOTALS: – – – Glycolysis makes 2 ATP for each glucose molecule w/o O2,that’s all the energy extracted w/ O2,the Kreb’s Cycle and the transport chain make 34 more ATP(36 molecules total,counting glycolsis)----18 x as much – These 36 molecules of ATP are 38% the total energy in glucose…actually efficient – The other 62 % is released as _______________---one reason why you feel warmer after exercise D)ENERGY AND EXERCISE • Glycolysis covers a few seconds of a runners run • Next –lactic acid fermentation produces ATP w/o O2 present 15 • • At end of race,runner breathes extra to use O2 to help rid body of lactic acid • For long term energy(eg. Cross-country running),cellular respiration releases a continual supply of ATP • Muscles store _____________ that help out w/ about 20 min. of activity After that,stored fats are broken down E. Comparing Photosynthesis & Cellular Respiration – __________________deposits energy by making glucose – ____________________withdraws energy by breaking down glucose – Photosynthesis removes CO2 from atmosphere and cellular respiration puts it back. – Photosynthesis releases ____ into atmosphere and Cellular Respiration uses it to release energy from food. – Cellular Respiration happens in eukaryotes and some prokaryotes and________________________only happens in plants ,algae and some bacteria. 16