Plant Physiology Quiz 2 Study Guide PDF

**Plant Physiology Quiz 2 Study Guide** **Chapter 3: The Plant Cell and the Cell Cycle** 1. Structure of prokaryotic cell differ from eukaryotic cell because prokaryotic cells are don't have nucleus (their DNA is not surrounded by a membranous envelope). They have nucleoid which conta...

**Plant Physiology Quiz 2 Study Guide** **Chapter 3: The Plant Cell and the Cell Cycle** 1. Structure of prokaryotic cell differ from eukaryotic cell because prokaryotic cells are don't have nucleus (their DNA is not surrounded by a membranous envelope). They have nucleoid which contains the DNA. But eukaryotic cell has nucleus. Archaea and bacteria have prokaryotic cells. Most prokaryotic cells have one chromosome. Prokaryotic cells lake specialized membrane bounded structures(organelles) that perform specific functions. In eukaryotic cells, the chromosomes are surrounded by an envelope, made up of two membranes, which separates them from the other cell contents. The DNA in eukaryotic cells is linear and tightly bound to special proteins known as histones, forming several chromosomes that are structured more complex than bacteria chromosomes. Eukaryotic cells go through cell division that perform different functions. - E. coli is an example of a prokaryote, and it has cell wall, a plasma membrane, and cytoplasm. The DNA is found in the nucleoid which is in the center of each cell but is not surrounded by a membrane. 2. Plastids are characteristic components of plant cells, and they are concerned with such processes as photosynthesis and storage. The principle types of plastids are: 1. Chloroplasts, chromoplasts, and leucoplasts. Each are surrounded by envelope of two membranes. - Chloroplasts are the sites of photosynthesis, it contains chlorophylls and carotenoid pigments. The chlorophyll pigments are responsible for the green color of these plastids. The carotenoids are yellow and orange pigments that, in green leaves, are masked by the more numerous chlorophyll pigments. Chloroplasts are found in plants and green algae. - Chromoplasts are also pigmented plastids. Of variable shape, chromoplasts lack chlorophyll but synthesize and retain carotenoid pigments, which are often responsible for the yellow, orange, or red colors of may flowers, aging leaves, some fruits, and some roots, such as carrots. - Leucoplasts lack pigments and an elaborate system of inner membranes. Some leucoplasts, known as amyloplasts, synthesize starch, whereas others are thought to be capable of forming a variety of substances, including oils and proteins. 3. The endoplasmic reticulum is the initial source of membranes. Transition vesicles from the endoplasmic reticulum transport new membrane material to the Golgi apparatus, and secretory vesicles derived from the trans-Golgi network contribute to the plasma membrane. The trans-Golgi network also supplies vesicles that fuse with the tonoplast and thus contribute to formation of the vacuoles. The endoplasmic reticulum, Golgi apparatus, and trans-Golgi network, therefore, may be considered a functional unit in which the Golgi bodies serve as the main vehicles for the transformation of endoplasmic-reticulum-like membranes into plasma-membranelike and tonoplast-like membranes. 4. The cytoskeleton of the cell is a dynamic three-dimensional network of protein filaments (microtubules and actin) that extends throughout the cytosol and is intimately involved in many processes. These processes include: 1. Cell division, 2. Growth, 3. Differentiation, 4. Movement of organelles from one location to another within the cell. 5. Primary wall are the first wall layers to form. It contains primary pit-fields. Found in actively dividing and actively metabolizing cells. Secondary wall are formed in some cells after the primary wall is laid down. Located interior to the primary wall. Contains pits. Found in cells with strengthening and/or waterwall is laid down. Located interior to conducting functions. Is rigid and thus imparts added strength. End of chapter questions: 1. Cell theory is the theory that everything alive has cell membrane. The significance of this theory for biology is that in order for us to study life we need to know what is the basic unit oflife, which is the cell. 2. Three features of plant cells that distinguish them from animal cells are: 1. Plant cell walls are made of cellulose 2. Plant cells have chloroplasts( where photosynthesis happens) 3. Have larger Vacuoles. 3. Plastids and mitochondria are said to be "semi-autonomous" organelles because both have their own DNA, ribosomes, and can make their own proteins. 4. Vacuoles are important storage compartments for primary metabolites, such as sugars and chlorophyll. Vacuoles are also involved in the breakdown of macromolecules and the recycling of their components within the cell. 5. The phenomenon of autumn leaf coloration happens because the leaves lose the ability to synthesize chlorophyll due to the shortened sunlight and drop of temperature which makes the colors of the leaf go from green to yellow/ orange. 6. Rough ER is complex, three-dimensional membrane system that spreads throughout the entire cytosol. Cells that store proteins have abundant rough ER, which consists of flattened sacs, or cisternae, with numerous polysomes on their outer surface. Whereas the cells that produce and release lipids have smooth ER, which lacks ribosomes and is largely tubular in form. 7. Microtubules are thin, cylindrical structures of 24 nanometers in diameter and varying lengths, they are composed of subunits of the protein tubulin. They cause cell division, the growth of the cell wall, and the movement of flagella. Actin filaments composed of actin protein. Has filaments of 5 to 7 nanometers in diameter. The main function of Actin filaments is cytoplasmic steaming. **Chapter 4: The Movement of substances into and out of Cells** 1. Water potential is the potential energy of water. Water moves from a region of higher water potential to one of lower water potential. The concept of water potential is useful because it allows plant physiologists to predict how water will move in the plant under various conditions. 2. Diffusion is the dispersion of substances by the movement of their ions or molecules, which tends to equalize their concentrations throughout a system. Osmosis is the movement of water molecules across a selectively permeable membrane. Substances that move by diffusion are: water, oxygen, carbon dioxide, and other small, simple molecules move freely across the plasma membrane via diffusion. Nonpolar molecules like oxygen and carbon dioxide, which are soluble in lipids, move easily through the lipid bilayer. Small, uncharged polar molecules can also diffuse through temporary openings created by the movement of membrane lipids. **Osmosis:** Water is the primary substance that moves via osmosis across a selectively permeable membrane2. The presence of a solute decreases the water potential, which creates a gradient that drives the movement of water during osmosis2. The solute itself does not move across the membrane in osmosis. 3. The basic structure of cellular membranes consists of a **lipid bilayer** in which **globular proteins** are embedded1. Many of these proteins extend across the bilayer and protrude on either side. 4. **Transport proteins** are proteins that facilitate the movement of substances across cellular membranes1. These proteins are crucial for the life of plant cells because they allow the passage of polar substances and other molecules that cannot freely diffuse through the lipid bilayer of the membrane. transport proteins are essential for the life of plant cells because they provide the means to move a wide range of molecules across the plasma membrane. They also help establish and maintain gradients, and enable cellular communication. 5. Both **facilitated diffusion** and **active transport** use **transport proteins** (specifically carrier proteins) embedded in the cell membrane to move substances across. Both processes are involved in the transport of substances that cannot easily diffuse through the lipid bilayer of the cell membrane, such as ions and polar molecules. **facilitated diffusion** is a passive process that aids in the movement of substances down their concentration gradients, while **active transport** is an energy-requiring process that moves substances against their gradients. 6. Vesicle-mediated transport is a mechanism used by cells to move large molecules and particles across the plasma membrane that are too large to be transported by transport proteins1. This process involves the formation of vesicles that either bud off from or fuse with the plasma membrane. Vesicle-mediated transport is crucial for moving large substances into and out of the cell1.Exocytosis involves the fusion of vesicles with the plasma membrane to release contents outside the cell, whereas endocytosis involves the formation of vesicles from the plasma membrane to bring materials inside the cell1.These processes are critical for cellular function, communication, and maintaining the integrity of the cell membrane. 7. signal transduction involves chemical messengers and receptors on the plasma membrane, while plasmodesmata are physical channels between cells that facilitate the direct transport of molecules and electrical signals. Both mechanisms are essential for cell-to-cell communication, enabling coordinated function in multicellular organisms. End-of-chapter questions: 1-8 1. the key distinction lies in the direction of movement relative to the concentration difference and the energy input needed for the transport. Movement down a concentration gradient is a passive process driven by the concentration difference, whereas movement against a concentration gradient is an active process that requires energy to move substances against the concentration difference. 2. Adding salt to the soil results in a decrease in the water potential of the soil, causing water to move out of plant cells. This leads to plasmolysis, a loss of turgor pressure, wilting, and the disruption of essential cellular processes, making it difficult or impossible for plants to survive in the saline environment. 3. The lower water potential, ample moisture, and rich nutrients inside sewer pipes, along with the physiological processes of osmosis and turgor pressure, create a highly attractive environment for root growth, leading to clogs and blockages, especially during the spring growing season1. 4. **primary active transport** by the **proton pump** establishes the **proton gradient**, and this stored energy is then used by **proton-coupled transport** systems to move other molecules against their concentration gradients. The example of **sucrose-proton co-transport** shows how this process allows plant cells to accumulate sugars, even when the sugar concentration inside the cell is higher than outside the cell. 5. vesicle-mediated transport is a way for cells to move large molecules and particles that are too big to pass through membrane transport proteins. Endocytosis and exocytosis are two opposing processes that utilize vesicles for the import and export of materials. 6. **phagocytosis** is a non-specific process that engulfs large particles, whereas **receptor-mediated endocytosis** is a specific process that uses receptor proteins to internalize specific molecules. 7. **reception** is where the signal is received, **transduction** is how the signal is relayed and amplified within the cell, and **induction** is how that signal leads to a specific cellular response. 8. Viruses spread from cell to cell in plants via **plasmodesmata**. These are channels that connect the cytoplasm of adjacent plant cells, allowing the movement of molecules between them. The plant\'s symplast ,which is the interconnected protoplasts and plasmodesmata, forms a continuous network that viruses can utilize for transport. A diagram of cell structure Description automatically generated