Topic 3 Complete Notes (PDF)

Topic 3a Specialized and Organized.notebook May 22, 2014 Do Now Problems: 1. Draw the Lewis structure for carbon tetraflouride. 2. What are the three parts of the modern cell theory? Topic 3a ­ Specialized and Organized Cel...

Topic 3a Specialized and Organized.notebook May 22, 2014 Do Now Problems: 1. Draw the Lewis structure for carbon tetraflouride. 2. What are the three parts of the modern cell theory? Topic 3a ­ Specialized and Organized Cells make up all life on Earth. Today, we broaden our examination of cells by looking at a group of organisms: the plants Plants are multi­cellular organisms that form the basis of all energy requirements of all organisms on Earth 1 Topic 3a Specialized and Organized.notebook May 22, 2014 Cellular Organization All multi­cellular organisms are made up of several cells. Most multi­cellular organisms have specialized cells that are designed for specific functions The organization of cells is as follows: o The basic unit of an organism is a cell o Cells of similar design and function that are grouped together for a common purpose make up tissue o Groups of tissue that work towards a common function make up an organ. o A group of organs working together to complete a more general common function make up an organ system o Several organ systems working together make up the organism 2 Topic 3a Specialized and Organized.notebook May 22, 2014 There are different organs of plants: leaf, stem, roots. Plants have many functions in order to survive. o Take in water, create glucose, transport water and minerals, etc. NOT all cells perform ALL functions, specialized cells perform specific tasks All specialized cells work together to help the whole plant survive Main job of the organs: a) leaves: make food through photosynthesis (and gas exchange) 3 Topic 3a Specialized and Organized.notebook May 22, 2014 b) stem: transport water and nutrients throughout the plant c) roots: uptake of water and nutrients 4 Topic 3a Specialized and Organized.notebook May 22, 2014 Cell specialization in the leaves Contain several types of specialized cells that function in photosynthesis. o This occurs in the chloroplasts of the cells. o Chlorophyll in the chloroplasts traps light energy from the sun and in a reaction with water (from the soil) and carbon dioxide (from the air) creates glucose; the plant and animals source of energy, and oxygen gas. Reaction: 6CO2(g) + 6H2O(l) + light à C6H12O6(s) + 6O2(g) 5 Topic 3a Specialized and Organized.notebook May 22, 2014 Cellular respiration is the opposing reaction that occurs in a plant and animal cells mitochondria to convert glucose into usable energy (ATP). The structure and arrangement of cells in the leaf are determined by the task they must perform. Different types of leaf cells have different structures and arrangements Worksheet ­ show function/structure of each leaf cell. 6 Topic 3a Specialized and Organized.notebook May 22, 2014 Cell, Tissue, Organ, System Advantages to being multicellular are: o larger size o variety of specialized cells o ability to thrive in a range of environments. However, the cell must be very organized. Level of Cell Tissues Organs Organ Systems Organization Similar cells Multiple tissues can be cluster arranged in combination Organs and tissues Most basic together to form organs eg) root, perform and share a Description unit of form tissues stem. Different tissues complex function eg) organization share same work together to enable digestive system, function and organs to perform a vascular system structure specific function 7 Topic 3a Specialized and Organized.notebook May 22, 2014 Read pg 318 ­ 324 CYU Q #1­5 Do Now Problems: 1. Balance the reaction below and classify the type of reaction: C5H12 + O2 ­> CO2 + H2O 2. Name two important aspect of the structure of epidermal leaf cells and explain why they are important. 8 Topic 3a Specialized and Organized.notebook May 22, 2014 Leaf Cells Stomata 9 Topic 3a Specialized and Organized.notebook May 22, 2014 Vascular Bundle Phloem and Xylem 10 Topic 3a Specialized and Organized.notebook May 22, 2014 Text Section 9.2 Gas Exchange in Plants As humans, we breathe and our body uses the gases in the air and distributes them throughout our body via our blood. Plants do not have this lung/blood system ­ how do they exchange gases? The stomata allow gases to diffuse in and out of the leaf Inside the leaf there are spaces between cells and the gases move through these spaces CO2, O2, H2O move by passive transport between plant cells and surroundings. Figure 9.5 page 325. Lenticels allow for gas exchange as well and are found on stems. 11 Topic 3a Specialized and Organized.notebook May 22, 2014 To break down glucose into energy plants must consume some O2 and produce CO2 and H2O through cellular respiration During photosynthesis, plants consume CO2 and H2O and release O2 Photosynthesis consumes way more CO2 and H2O than is produced in cellular respiration Most important gas exchange organ is the leaf air diffuses through stomata into leaf circulates in spaces between spongy and palisade tissue cells CO2 diffuses into cells down the concentration gradient CO2 used in chloroplasts during photosynthesis O2 produced leaves chloroplast cells into air spaces O2 then diffuses through stomata and out of leaf 12 Topic 3a Specialized and Organized.notebook May 22, 2014 Gas Exchange is tied to Water Loss When stomata are open to allow gas exchange, water is also lost from the leaf. This evaporation of water from the leaf's stomata is called transpiration. Guard cells help prevent the dehydration of the plant. Guard cells control the stomata Stomata open: CO2, O2, H2O exchange ­ high photosynthesis, high transpiration Stomata closed: gas/water exchange low ­ low photosynthesis, low transpiration The opening and closing of the stomata is determined by the amount of water in the guard cells. 1. lots of water in leaf causes water to flow into guard cells 2. water in guard cells cause them to swell and stomata opens 3. gas exchange commences and some water is lost through transpiration 4. as water is lost, it leaves the guard cells. Deflated guard cells cause the stomata to close. 13 Topic 3a Specialized and Organized.notebook May 22, 2014 More Explanation from Page 329 Recall ­ water moves into and out of cells via osmosis As water moves into the guard cells, the water pressure inside the cells increases and causes the cells to swell. This high water pressure is called turgor pressure. Turgor pressure pushes the elastic cell membrane against the rigid cell wall. The swollen guard cell changes shape => this action causes opening of the stomata Water vapour then passes out of the leaf through transpiration. Transpiration causes water to be lost from the plant cells. As the amount of water in the guard cells decreases, the cells deflate and change shape again => this action causes closing of the stomata Most plants have stomata open during day and closed during night. Plants in very dry, hot climates stomata will close during the day and open at night (gather CO2 and store it until day time) Stomata can help decrease H2O loss, but a plant can still dry out if its water source is depleted. 14 Topic 3a Specialized and Organized.notebook May 22, 2014 Read pg 325 ­ 330 CYU Q # 1­4 Text Section 9.3 ­ Water Transport in Plants with in individual cells, water is transported by osmosis in an entire plant, water must be transported over much larger distances. 15 Topic 3a Specialized and Organized.notebook May 22, 2014 Plant vascular system Xylem ­ transports water from roots to leaves. Phloem ­ transports sugar from leaves to rest of plant. Water up take in roots Minerals enter root through facilitated diffusion or active transport. Water enters root hairs through osmosis, diffuses through root to xylem (root hairs increase surface area for maximum water and mineral absorption) Water and minerals gather at the root xylem = xylem sap This xylem sap is then carried upwards towards the leaves. 16 Topic 3a Specialized and Organized.notebook May 22, 2014 Sugar transport in phloem water from roots and CO2 from the air prepare leaf for photosynthesis the sugars produced by the palisade tissue cells and spongy tissue cells provide the whole plant with energy. Sugars, minerals and other nutrients are pumped into the phloem through active transport As the sugar concentration increases within the phloem cells, water follows the sugar by osmosis (sugar solution is hypertonic in comparison to the surrounding cells) This phloem sap then flows down the concentration gradient down the phloem and into neighbouring cells. Companion Cells ­ page 332 ‐ Without companion cells phloem would not be able to carry sap very well as the cells would be clogged up with all sorts of organelles. ‐ They are essentially personal assistants for the phloem cells. 17 Topic 3a Specialized and Organized.notebook May 22, 2014 Please Read pages 331 ­ 340 and answer CYU questions 3 ­ 7 on page 340 Do Now: 1. Balance and classify each reaction: ___NaCl + ___ Fe2O3 ­­> ___Na2O + ___FeCl3 ___ H2 + ___ O2 ­­> ___H2O 2. Explain why companion cells are important to the function of the phloem in plants. 18 Topic 3a Specialized and Organized.notebook May 22, 2014 Text Section 9.4 Plant Control Systems http://www.youtube.com/watch?v=ktIGVtKdgwo Multicellular organisms respond to environmental factors called stimuli by moving Plants also have systems in place to allow them to respond to the changes in the environment (not as obvious as other organisms). These responses are called tropisms. 19 Topic 3a Specialized and Organized.notebook May 22, 2014 1. Phototropism Light is very important stimulus to plants (for photosynthesis) Plants will grow towards a light source to maximize photosynthesis. How? By cells growing at different rates. If one side of the plant grows elongated (lengthened) cells, the stem will curve. (cells closer to the sun will not elongate, cells further from the sun elongate) The tip of the plant will send signals to the stem to control rate of cell growth Chemical that stimulates elongation of cells (Auxin) 2. Gravitropism Response to gravity Stems grow against gravity (negative gravitropism) Roots grow towards gravity (positive gravitropism) Plants do it to meet their needs i. Roots that grow down are more likely to find soil, water, and minerals ii. Stems that grow up get the light required for photosynthesis also involves the action of auxin to help curve the stem or root in the right direction. In roots, auxin inhibits growth of cells In stems, auxin stimulates growth of cells. 20 Topic 3a Specialized and Organized.notebook May 22, 2014 Nastic Response Touch sensitive plants (Venus Fly Trap, Mimosa) rely on pressure and a complex series of cell membrane actions to move. http://www.youtube.com/watch?v=BLTcVNyOhUc Complete CYU questions 1 ­ 8 on page 348. 21 Topic 3a Specialized and Organized.notebook May 22, 2014 22