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A&P Chapter 4
Question | Answer |
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Where is most of the water in animals found? | found inside the cell and is called intracellular fluid. |
What is diffusion? Is it an active or a passive membrane process? | The process of moving down the concentration gradient from an area of high concentration to a region of low concentration. Diffusion is a passive membrane process. |
What molecules are more likely to diffuse into a cell? | Water, oxygen, and carbon |
What effect does a hypotonic solution have on a cell? What passive membrane process causes this effect? | If the extracellular fluid is hypotonic, the inside of the cell is more concentrated than the outside. In this scenario, water flows into the cell and causes it to swell and possibly burst. This effect is due to the process known as osmosis. |
When is a membrane process considered “active”? | when the cell is required to use energy (ATP). They cannot move through the plasma membrane passively. |
How do electrolytes enter the cell? | Electrolytes enter cells via active transport without the assistance of a concentration gradient. |
Describe the three types of endocytosis. | • Phagocytosis – cells engulfs solid material • Pinocytosis – cells engulfs liquid • Receptor-mediated endocytosis – cells that have specific proteins in their plasma membrane |
What is the difference between excretion and secretion? These are both examples of what? | Excretion is the movement of waste products from the intracellular to the extracellular environment, and secretion is the movement of manufactured molecules from the intracellular to the extracellular environment. Both are examples of exocytosis. |
What are the principal ions involved in maintaining a cell’s resting membrane potential? | Sodium and potassium |
Is there normally a higher concentration of sodium inside or outside of the cell? Where is there a higher concentration of potassium? | Sodium is 10 to 20 times higher outside the cell than it is inside. Potassium is 10 to 20 times higher inside the cell than outside. |
What is the term for mRNA formation? | Messenger RNA (mRNA) formation is known as transcription. |
What are codons and what role do they play in transcription? | A codon is a set of three adjacent nucleotides in an mRNA molecule that specifies the incorporation of an amino acid into a polypeptide chain or that signals the end of polypeptide synthesis. |