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27 Cards in this Set
- Front
- Back
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Compare and contrast prokaryotic cells to eukaryotic cells. |
Prokaryotic: Nucleoid (no nuclear membrane)
Eukaryotic: Nucleus (w/ nuclear membrane), membrane bound organelles, presence of mitochondria, chloroplasts, cell walls, generally larger than prokary. because much more complex
Both: Presence of plasma membrane, cytoplasm, ribosomes, DNA |
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Why are cells generally so small? |
Needs to be a high surface area to volume ratio for efficient diffusion of water, nutrients, disposal of waste. |
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What sets the upper/lower limits of cell size? |
Upper limit: Cellular metabolism, SA:V ratio Lower limit: Must be large enough to contain DNA to program metabolism, enzymes to carry out necessary activity to sustain cell |
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Describe the parts and function of the nucleus. |
Nuclear envelope: Double lipid bilayer enclosing nucleus. Has pore complex, continuous with ER. Pore complex regulates entry/exit of macromolecules and other particles
Nucleolus: Produce ribosomes. Nucleus always has 1+ nucleoli
Chromatin: Genetic material. Consists of DNA and proteins |
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Describe structure and function of mitochondrion |
Cellular respiration, produce ATP Double membrane, cristae to make cellular respiration more efficient. |
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Describe structure and function of chloroplasts |
3 compartments: Intermembrane space, stroma, thylakoids. Photosynthetic, convert light energy into sugars |
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Describe structure and function of central vacuole |
Membrane bound sac found in plant cells. Storage, breakdown of waste, hydrolysis of macromolecules. Maintain proper pressure within plant cell to provide structure and support in growing cells. Larger in older plant cells. |
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Describe structure and function of endoplasmic reticulum |
Membrane synthesis. Continuous with nuclear envelope
Rough ER: Bound ribosomes. Produce proteins to be secreted or inserted into plasma membrane
Smooth ER: No ribosomes. Detoxify poisons, store calcium ions, metabolize carbohydrates, synthesize lipids. |
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Describe structure and function of golgi apparatus |
Synthesize, modify, sort, and secrete cell products (proteins) Stacks of cisternae. |
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Contrast location and function of bound ribosomes to free ribosomes |
Bound: Attached to rough ER. Produce proteins made to go into cell membrane or secreted out of cell.
Free: Suspended in cytoplasm. Produce proteins that are used within cytosol. |
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What does the endomembrane system do for the cell? |
Regulates protein traffic and performs metabolic funtions |
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Which cellular structures make up endomembrane system? How are they connected? |
Includes ER, golgi apparatus, nuclear envelope, lysosomes, vacuoles, plasma membrane Connected through direct continuity or transfer of vesicles |
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What are examples of types of cells that would have extensive smooth ER? Extensive rough ER? How are these related to the function of smooth/rough? |
Smooth: Muscle cells. Needs to be able to store a lot of calcium ions to be released to trigger contractions Rough: Certain cells in pancreas. Secrete insulin |
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A vesicle buds off the ER. Explain what happens to the vesicle and it's contents as it reaches, moves through, and exits the golgi apparatus. |
1. Vesicle merges into cis face of golgi 2. Cisternal maturation (proteins are modified) 3. Molecular identification tags added to target for specific part of cell or extracellular destination 4. New vesicle forms, leave golgi with specific proteins to other locations or plasma membrane for secretion |
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What is contained in a lysosome? What is its function? Where is it made? |
Contains hydrolytic enzymes. Digest macromolecules. Made in rough ER |
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What is phagocytosis? How are lysosomes involved? Example from your body? |
Eat by engulfing smaller organisms/food particles. Phagocytes use enzymes in their lysosomes to break down particles White blood cells are phagocytes |
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3 types of vacuoles? Function and what types of organisms to find them in? |
Food vacuole: Digestion. Fuses w/lysosome by phagocytosis, lysosome enzymes digest food. Found in amoeba and other protists
Contractile vacuole: Pump excess water out of cell to maintain proper concentrations of salt/other molecules. Found in freshwater protists
Central vacuole: Hold reserves of important organic compounds. Main repository for inorganic ions like potassium and chloride. Disposal for metabolic byproducts. Protect plant by containing bad-tasting or poisonous compounds. Maintains proper pressure within growing cells. Structural support. Found in plant cells. |
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2 things mitochondria and chloroplasts have in common. Why are they not considered part of the endomembrane system? |
Convert energy, grow and reproduce within cell. They have their own DNA, neither come from the ER |
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Describe the structure of a mitochondrion. Why is the folding of the cristae important? |
Enclosed by phospholipid bilayer. Outer membrane smooth, inner membrane had infoldings called cristae. Cristae creates more surface area which makes cellular respiration more efficient |
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Define cytoskeleton. 3 types of fibers that make up cytoskeleton? |
Network of fibers that organizes structure and activities in cell. Microtubules, microfilaments, intermediate filaments. |
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Describe structure and main function of the 3 fibers that make up cytoskeleton. |
Microtubules: Hollow tubes, wall consists of columns of tubulin molecules. Largest fiber. React with motor proteins to move chromosomes, granules, organelles. Structural support
Microfilaments: 2 intertwined strands of actin. Smallest fiber. Makes up muscle. Cell movement. Cytoplasmic streaming. Structural support
Intermediate filaments: Fibrous proteins supercoiled into thicker cable. Medium fiber. Plasma membrane structural support. Only fiber NOT involved in cellular movement |
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What is a motor protein? How does it aid in whole cell movement? How does it aid in organelle movement? |
Work w/cytoskeletal elements and plasma membrane molecules allow whole cells to move along fibers outside of the cell. Grip microtubules within flagella/cilia and propel them. Links to organelle and microtubule, microtubule acts as railway for organelles. |
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What is cytoplasmic streaming? |
Circular flow of cytoplasm within cells, speeds up distribution of materials. Microfilaments move to create cytoplasmic streaming |
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4 functions of cell wall? |
Protect cell, maintain shape, prevent excessive uptake of water, hold plant up against gravity |
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What are the main ingredients of the ECM (extra cellular matrix)? What is its function? |
Collagen, embedded in a network woven from proteoglycans. Structural and biochemical support to surrounding cells, cell to cell communication, cell adhesion |
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What are intracellular junctions? |
Junctions through which cells interact and communicate by exchanging information. |
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4 types of intracellular junction? What types of cells have them? Their functions? |
Plasmodesmata: Plant cells. Perforated channels cytosol passes through to connect the chemical environment of adjacent cells
Tight junctions: Animal cells. Prevent leakage of extracellular fluid across layer of epithelial cells
Desmosomes: Animal cells. Fasten cells together in strong sheets
Gap junctions: Animal cells. Provide cytoplasmic channels from one cell to an adjacent cell. Allows cell communication |
