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20 Cards in this Set
- Front
- Back
Prokaryotic v Eukaryotic Cells
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The distinction between prokaryotes and eukaryotes is considered to be the most important distinction among groups of organisms. Eukaryotic cells contain membrane-bound organelles, such as the nucleus, while prokaryotic cells do not.
Prokaryotes were the only form of life on Earth for millions of years until more complicated eukaryotic cells came into being through the process of evolution |
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The Cell Structure of Eukaryotic Cells
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Differences between Plant and Animal Cells
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Cell Membrane
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A protective layer that surrounds every type of cell. It supports the cell and allows for molecules to diffuse in and out of the cell.
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Cell Wall
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A protective layer that only plants, fungi, and bacteria have. It is the outer most shell that helps support the organism as well as allow molecules to diffuse.
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Nucleus
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It controls cell activity and contains DNA.
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Cytoplasm
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Jelly-like substance inside of cells that helps to support and protect the cells organelles.
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Endoplasmic Reticulum
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It is a network of tubes that connects to the nuclear tube and the cell membrane. It carries materials through the cell and aids in making proteins.
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Ribosomes
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They are small bodies that can either be attached to the ER or free floating. They are made of rRNA & protein and help synthesize proteins.
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Mitochondria
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Mitochondria breaks down sugar molecules to release energy. It is the site of aerobic cellular respiration. The mitochondria itself is peanut shaped with a double membrane.
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Vacuole
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Fluid filled sacs that store food, water, metabolic and toxic wastes.
In plants, they are the largest organelle and store larger amounts of sugar. |
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Chloroplast
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They contain chlorophyll and conduct the process of photosynthesis. They have a double membrane with inner membrane modified into stack of thylakoids.
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Golgi Apparatus
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It is a stack of flattened sacs modify proteins made by the cell and then 'packages' and exports them.
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Six types of transfer mechanisms
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diffusion
osmosis passive transport active transport exocytosis endocytosis |
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Passive transport mechanisms
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This is a broad category of transport mechanisms that includes diffusion, osmosis, and filtration.
Unlike Active Transport, it does not require an input of chemical energy. |
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Diffusion
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This occurs when molecules are small enough to pass freely across cellular membranes.
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Facilitated Diffusion
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A special carrier protein located on the cell membrane has a central channel which acts as a selective corridor which helps molecules move across the membrane.
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Osmosis
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It is a special case of diffusion.
For example, the starch molecule is too large to pass through the pores in the cell membrane, so it cannot diffuse from one side of the membrane to the other. The water molecules can, and do, pass through the membrane. Hence the membrane is said to be semipermeable, since it allows some molecules to pass through but not others. However, on the side of the membrane with the starch, the starch molecules interfere with the movement of the water molecules, preventing them from leaving as rapidly as they enter. Thus, more water flows into the side with the starch than flows out, and the starch gets diluted. |
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Active Transport
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A kind of transport wherein ions or molecules move against a concentration gradient, which means movement in the direction opposite that of diffusion – or – movement from an area of lower concentration to an area of higher concentration. Hence, this process will require expenditure of energy, and the assistance of a type of protein called a carrier protein.
An example of a carrier protein would include the sodium-potassium pump. |
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Endocytosis and Exocytosis
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Endocytosis is the process that moves molecules from outside of the cell to the inside of the cell.
Exocytosis is the process where molecules from inside of the cell move to the outside. |