BY 124 1st Edition Lecture 5 Outline of Last Lecture Chapter 35 I II III IV V VI VII Plant Tissue Systems Plant Growth Types of Plant Life Cycles Primary Growth Types of Primary Growth Secondary Growth Leaf Anatomy Chapter 36 I II III IV V Overview of Resource Acquisition and Transport in Vascular Plants Solute Transport Water Transport and Movement Transmembrane Routes Transport from Root Hairs to Xylem Outline of Current Lecture Chapter 36 I Transpirational Pull Cohesion Adhesion Mechanism II Mechanisms of Stomatal Opening and Closing III Movement Through Phloem IV Sieve Tubes Chapter 37 I II III IV V Essential Elements in Plants Cation Exchange Soil Bacteria and Nitrogen Plants That Have Relationships With Another Organism Nutritional Adaptations in Plants These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Current Lecture Chapter 36 cont I II III How does water get to top of tree once in xylem and phloem a Used to think it was root pressure i Only possible for small plants ii Hydathodes allows for guttation or the formation of droplets in margins of veins Figure 36 11 b Answer for trees Transpritational Pull Cohesion Adhesion Mechanism allows for water to move up trees Figure 36 13 1 Cohesion attracted to each other H bonds 2 Adhesion anything charged is attracted to anything else charged water and walls of plant ii Water column must be continuous You can t put it back together once it is completely broken 1 If slightly damaged cells can merge with others to make a new path Mechanisms of Stomatal Opening and Closing Figure 36 15 a Chloroplast in stomata Figure 36 14 b If plenty of water stomata will open i The stomata know this because guard cells are full of water and can lose water c If not a lot of water stomata close because guard cells become flaccid d Ways that things move through stomata i Deals with potassium ion in stomata 1 Chlorine ion follows potassium charge ii Relates to proton pumps and ATP e If not enough carbon dioxide stomata will close i Why Because carbon dioxide is needed for photosynthesis f Plants have a circadian rhythm i Normal rhythm is to open stomata every 12 hrs g Allowing water to leave through stomata not only pulls water up xylem but allows for evaporative cooling to keep plant from overheating Ways Things Move Through Phloem Figure 36 17 a Movement of sugar from leaves mesophyll through everything until it gets to sieve tubes phloem i Diffusion ii If you have active transport then you can get more out of it 1 Takes ATP energy to use proton pump a Sucrose is neutral so cannot use gradients IV Sieve Tubes i Sink is where sugar sucrose ends up a Make sugar in leaves by photosynthesis b Proton pumps load sugar into phloem c Water moves in form xylem by concentration gradient and causes sugar from source leaf to fall move down phloem to roots i Stored in sink cells d Water down at bottom of plant follows new concentration gradient and moves back into xylem to be drawn up to start cycle again Chapter 37 Soil and Plant Nutrition Remember that plants are photoautotrophs make own food by photosynthesis I II III Essential Elements in Plants Table 37 1 a nutrients come in as ions because they will be cofactors for enzymes b Macronutrients stuff you need a lot of i Nitrogen cannot be taken up from the atmosphere through atmospheric nitrogen 1 Need nitrate NO3 or ammonium NH4 ii Magnesium every molecule of chlorophyll needs it c Micronutrients i Iron cytochromes Cation Exchange Figure 37 3 a Plants use cation exchange to absorb nutrients from soil and water i Two protons H move out and one Calcium ion Ca2 moves in from soil because it is attracted to negative charge of root hair ii Excess nutrients stored in vacuole and xylem Soil Bacteria and Nitrogen Figure 37 10 a Nitrogen fixing bacteria nitrogen and turn it into NH3 i Or ammonifying bacteria take organic material humus and turn it into NH3 b Takes H from soil and turns NH3 into NH4 i Can go straight into plant at this point but sometimes it continues with following steps c Can take NH4 and use nitrifying bacteria to make NO3 nitrate i Denitrifying bacteria turns NO3 back to N2 atmospheric N d Rhizobium nitrogen fixing bacteria IV V i Cyanobacteria will also fix nitrogen ii Soybean plants will take bacteria into roots symbiotic 1 When soybeans uptake these bacteria cells become bacteroids Plants That Have Relationships With Another Organism a Mycorrhizae fungus root i Fungus are heterotrophs so take sugar from other plants ii Fungus good at breaking down stuff 1 Wood 2 Get phosphorous for plants a Water too iii Fungus has growth factors that help plant roots grow as their roots grow iv Protection Nutritional Adaptations in Plants Figure 37 15 a Epiphytes upon a plant ex Staghorn Fern i Don t take anything Just there because it needs the support b Photosynthetic parasites ex Mistletoe i Can survive on its own but takes from the tree because it is lazy c Nonphotosynthetic parasite ex Dodder d Nonphotosynthetic parasite of mycorrhizae ex Indian Pipe