Cell Structure, Function And Energy TAKS Review Cell Structure, Function And Energy Note: on the flash animation slides next button will flash when the current animation is complete. There may be sound, but I have not gotten it to work. There are specific points to discuss for each animation—these are suggestions only.

Have students make T-chart (prokaryotic and eukaryotic). Press play; ask S what major difference is. Ans: no nucleus/nucleus—S add to chart Press next when blinking; ask S for other differences Press next when blinking; shows circular and linear DNA—S add to chart Press next; no organelles/organelles—S add to chart Press next; small and large—S add to chart Press next; reproductive rates—S add to chart Press next; examples—S add to chart

Press Play; T ask S if Eukaryotic or prokaryotic? How do they know? T direct S to pay attention to areas highlighted in pink (starts with cell membrane) Press next; tell S cytoplasm is all the goo and organelles inside the membrane Press next; T ask S to recall function of organelles now labeled (cheat sheet for you on slide 5; only difference between Rough and Smooth ER is rough has ribosomes attached to surface) Press next; Ask S why nucleus is important; ans: protect DNA

Review organelles and fuction Remind S mitochondria is popular on TAKS Controls what enters and leaves makes proteins packages proteins provides energy : site of cellular respiration, conversion of food energy into usable energy (ATP) Transport system Breaks down old cell parts Review organelles and fuction Remind S mitochondria is popular on TAKS

Cell Part Function Cell membrane Controls what enters and leaves the cell Nuclear membrane Controls what enters and leaves the nucleus Nucleus Control center of the cell Chromosomes Genetic information in the nucleus Endoplasmic Reticulum Transport system in cell Ribosome Organelle makes proteins Golgi Body Organelle packages proteins Vacuole Stores water and/or waste Lysosome Breaks down old cell parts Mitochondria Organelle for cellular respiration – provides energy S can copy (not necessary) To expedite only have students copy: cell membrane, nucleus, ribosomes, vacuole, lysosome, mitochondria

Practice Question Which of these is a characteristic of body cells that require large amounts of energy? A They have a large number of mitochondria. B They have a supplementary Y chromosome. C They have a two-layer membrane. D They have a storage area for albumin proteins. Remind S to always associate mitochondria with Energy A

Direct S to note plants have large vacuole, chloroplast and cell wall---animals cells do not

Cellular Energy Photosynthesis Cellular Respiration Converts sunlight energy into high energy sugars Converts high energy sugars into usable energy (in the form of ATP) Takes place in the chloroplast Takes place in the cytoplasm and mitochondria Occurs mainly in plants and some bacteria Occurs in all organisms Read through with students—note highlighted words Emphasis: Only organisms that make energy need chloroplasts, but ALL organisms undergo cellular respiration because all organisms use energy (even plants);

Press play; ask S Where does most photosynthesis take place in plants (ans: leaves) Ask S where in leaf cells does photosynthesis take place? (ans: in chloroplasts) Review formula as it comes up S can copy here or copy on next slide

Photosynthesis Cellular Respiration 6CO2 + 6H2O + Energy  6O2 + C6H12O6 carbon dioxide + water + sunlight  oxygen + glucose Cellular Respiration Allow S to copy (words or equation) Emphasize that products and reactants are switched Emphasize the path of energy: sunlight to sugars, sugars to ATP (usable energy) 6O2 + C6H12O6  6CO2 + 6H2O + Energy oxygen + glucose  carbon dioxide + water + ATP

LOTS of energy released High Energy Sugars Glycolysis Oxygen No oxygen Aerobic AnAerobic Cellular Respiration Fermentation Emphasis: 1. Anaerobic pathway is fermentation and only releases a little energy Aerobic pathway gets a lot of E from sugars Remind students of vocabulary: aerobic is with oxygen; anaerobic is without oxygen LOTS of energy released A little energy released

Practice Question Energy conversion within an animal cell would be severely limited by removal of the cell’s — A mitochondria B chloroplasts C plastids D lysosomes Energy conversion is key word in Question A

Practice Question Which molecule provides most of the energy used to drive chemical reactions in cells? F DNA G RNA H ATP J ADP DNA and RNA are genetic materials Remind students ATP has more energy than ADP FYI: adenosine triphosphate/diphosphate H

Transport across the membrane Purpose: to move nutrients and wastes in and out of the cell and maintain… T ask S the purpose Click to reveal homeostasis Ask S for definition: balance, equilibrium, same… Homeostasis

Cell Membrane Structure The lipid bilayer is selectively permeable; only small, nonpolar molecules can pass. Other molecules need carrier or channel proteins. Emphasis: Lipid bilayer: double layered membrane Selectively permeable Proteins are present to help move big molecules

Concentration is a measurement of the amount of solute (in grams) compared to the volume of the solution (in liters) Grams per liter or g/L Concentrations change as particles and/or water move into or out of the cell

Movement can be passive or active. NO energy required Needs energy Simple diffusion Facilitated diffusion Osmosis Endocytosis Pinocytosis Phagocytosis Exocytosis Emphasize energy

Press play; water can move in and out of cell; many solutes can’t cross cell membrane. Movement of water is determined by relative concentration of solute. Press next; in a HYPERtonic solution, the area outside the cell is MORE concentrated and water moves out Press next; ISO means same—no NET movement Press next; in a HYPOtonic solution, the area outside the cell is LESS concentrated and water moves into the cell.

Diffusion vs. Osmosis Diffusion is the movement of PARTICLES from areas of high concentration to areas of low concentration Osmosis is the movement of WATER from areas of low solute concentration to areas of high solute concentration; water moves because the particles can’t Emphasis: idea that osmosis is to move water to balance concentrations

Simple Rule to remember: SALT SUCKS Salt is a solute. When it is concentrated inside or outside the cell, it will draw the water in its direction. This is why you get thirsty after eating something salty. Salt sucks….. Simple Rule to remember: SALT SUCKS

What is Active Transport?     What is Active Transport? Active = Energy Energy is used to move selected molecules into a cell, even if they are at a low concentration.

Practice Question Saltwater fish remove extra salt from their body by active transport through the gills. What is the result of this activity? A The salt becomes more chemically active. B Water balance is maintained in the blood. C The rate of energy production is decreased. D The cell membrane becomes less permeable to water. B Remember the purpose of movement across the membrane is to maintain homeostasis Keyword in answer is balance

Practice Question When a sea urchin egg is removed from the ocean and placed in freshwater, the egg swells and bursts. Which of these causes water to enter the egg? A Coagulation B Sodium pump C Active transport D Osmosis D

Practice Question On a hot summer day, a road-crew worker perspires and then feels thirsty as her body temperature increases. This response is an example of- A. releasing enzymes B. decreasing respiration C. assimilating proteins D. maintaining homeostasis D

Practice Question Which of these is a function of the cell membrane in all cells? A Producing cellular nutrients B Preserving cellular wastes C Neutralizing chemicals D Maintaining homeostasis D