Biology Chapter 3 Study Guide – Flashcards
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What are the functions of a cytoskeleton?
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The cytoskeleton supports and shapes the cell. Like your skeleton, the cytoskeleton forms the structure of the cell. Like your muscles, the cytoskeleton supports the cell.
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Nucleus
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Stores genetic information for the cell (in chromosomes)
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Endoplasmic reticulum
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Processes and packages the production of proteins and lipids.
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Ribosomes
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They link amino acids together to produce proteins.
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Golgi Apparatus
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They process, sort and deliver proteins.
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Cell membrane
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makes new membrane; channels for moving proteins; makes transport vesicles - carries certain molecules from place to place within a cell.
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Mitochondrion
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Transfer energy from carbohydrates to ATP (powerhouse of the cell); site of cellular respiration-converts food into energy that is usable for the cell
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Vaculoe
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the large, water filled sac found in plants; used for storage and water regulation
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Lysosome
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membrane bound sac that contains digestive enzymes - protect a cell from invaders.
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Centriole?
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They are used to allow and animal to divide it's cells.
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Cell walls in a plant
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stiff outer covering of plant cells -Provide protection and structure.
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Chloroplast
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in plants, trap sunlight energy and transfer the energy to carbohydrates; site of photosynthesis
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The endoplasmic reticulum
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is the long maze of membranes where proteins and lipids are produced.
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Vesicle
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membrane bound sac that transport proteins through the cytoplasm .
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Phospholipid
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The cell membrane produces phospholipids. The phospholipids form a bilayer that is in the same shape and form as the cell membrane. The top layer of the phospholipid is positively charged. The leftmost portion of the phospholipid is nonpolar.
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Cholesterol
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Cholesterol creates fat and energy for the body. Embedded in the phospholipid bilayer of a cell membrane
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Proteins
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Proteins promote cell growth and stature. Embedded in the phospholipid bilayer of a cell membrane
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What is the function of carbohydrates which are embedded in the phospholipid bilayer of a cell membrane?
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Carbohydrates are energy producers for the cell.
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What is the function of a phospholipid?
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A phospholipid detects a signal molecule and carries out an action in response.
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What is the fluid mosaic model?
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The fluid mosaic model is a scientific model designed to show us how phospholipids travel through the cell membrane.
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What is selective permeability?
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Selective permeability is when the cell membrane allows some, but not all, molecules to cross.
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Phagocytosis
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Means "cell eating" and describes a type of endocytosis. A cell may transport a substance in Phagocytosis if the substance is too large to cross the membrane.
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Which unit of measurement is used to measure the size of cells AND what fraction of a meter is this unit?
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Cells are measured in nanometers. Thos is 1/100 of a meter. Cell parts are measured in atometers. Theses are 2/1000 of a meter.
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Explain the role of surface area: volume ratio in the functioning of cells.
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Cells have surface area and volume. We can use these measurements to help us scale out the different parts.
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How did the works of Schleiden, Schwann, and Virchow all contribute to the cell theory?
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Each one of these scientists were able to identify at least one part of the cell theory, one step at a time, and help form the basis for the study of life.
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List 4 structures found in ALL cells.
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. Cytoplasm . Enzymes . Receptor Protein . Cell Membrane
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List 3 structures found in plants and not in animals.
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. Cell Wall . Cytoplasm . Central Vacuole
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Describe the structure of a cell membrane. Be sure to include: phospholipid, bilayer, marker protein, transport protein, receptor protein, enzyme.
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Cell membranes are formed by bilayers of phospholipids. Cell membranes use transport proteins to carry materials around the cell. Marker proteins help the membrane identify itself. Enzymes are also used by the membrane to assist in speeding up chemical reactions.
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How is it that the cell membrane acts as a barrier?
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The cell membrane allows some materials to pass while keeping harmful ones out through selective permeability, like a barrier.
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How do the folds in the inner membrane of the mitochondria, or the stacked membranes of the chloroplasts, help those organelles do their job?
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These are molecules designed to assist the cell in creating energy. Without this, many cell structures will not function properly because there is not enough power for them to do so.
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Is a concentration gradient needed for passive transport? Why or why not
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A concentrated gradient is needed for passive transport. Naturally, molecules move from areas of high concentration to areas of low concentration. Diffusion and Osmosis are types of passive transport.
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Is a concentration gradient needed for diffusion? Why or why not?
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Like passive transport, diffusion requires the molecules move from areas of higher concentration to lower concentration for the same reasons as in passive transport.
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What is the difference between diffusion and equilibrium?
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Diffusion is the passage of molecules from one place to another through a membrane. Equilibrium simply means that molecules are of the same concentration on both sides.
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Describe the motion of molecules when a substance is in equilibrium across the cell membrane.
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The motion of equilibrium substances across the membrane does not chanfe or fluctuate, it simply remains fluent and constant.
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Explain how the size of a molecule affects its rate of diffusion.
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If a molecule is too big, then a molecule cannot diffuse as well as the smaller molecules.
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Explain how temperature affects the rate of diffusion.
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At hotter temperatures, diffusion happens faster than at colder temperatures.
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If a substance is less concentrated outside a cell than inside a cell, in which direction is that substance likely to diffuse across the cell membrane?
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The substance will likely diffuse from the higher concentrated area to the lower concentrated area.
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Is a concentration gradient needed for osmosis? Explain why or why not.
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A concentrated gradient is not needed for osmosis if it is facilitated. Like in previous discussions, molecules tend to move "from high to low" unless the movement is active or facilitated.
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What is the difference between diffusion and osmosis? How are they related?
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Diffusion can involve any molecule. Osmosis is a process specific to water molecules.
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What would happen to an animal cell if it were placed in a(n): hypertonic solution?
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The cell would burst because there is too much water in the cell. If there are more particles within a substance, then there is more energy. Hyper means big
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What would happen to an animal cell if it were placed in a(n):hypotonic solution?
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The cell would become grainy and lose it's water supply. There is not enough water left at that point to support the cell. Hypo means small
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What would happen to an animal cell if it were placed in a(n): isotonic solution?
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Nothing would happen. The cell's water levels would be completely normal.
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Describe how the diffusion of ions or polar molecules across a cell membrane differs from the diffusion of nonpolar molecules across the cell membrane.
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Polar molecules diffuse across a membrane faster than nonpolar molecules.
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Give four examples of facilitated diffusion.
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1. Water travels through your skin after you shower. 2. Water is brough up forcefully through a drain. 3. When we drink, we make the diffusion faster. 4. Transport proteins carry water through a cell membrane.
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What is the difference between passive transport and active transport? How are they similar?
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Passive transport requires no energy while active transport uses cellular energy to make molecules travel from lower concentrations to higher concentrations.
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Distinguish between endocytosis and exocytosis. Are these processes active or passive transport?
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Endocytosis involves molecules becoming engulfed into the membrane while exocytosis involves atoms being released from the cell. This is a form of active transport.
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What kinds of molecules are transported via endocytosis and exocytosis? Why?
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Macromolecules are transported through endocytosis and exocytosis. These larger molecules require more energy than in simple diffusion.
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