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Questions and Answers
What happens to a cell's surface area to volume ratio as it grows larger?
Which of the following is a strategy cells use to maintain a high surface area to volume ratio?
What is the main reason larger cells experience slower diffusion rates?
Which feature do eukaryotic cells utilize to increase their internal surface area?
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What is a consequence of a reduced surface area to volume ratio in a cell?
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What is the primary function of the nucleus in a cell?
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Which organelle is responsible for the synthesis of proteins?
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Which part of the endoplasmic reticulum is involved in lipid synthesis?
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What is the role of the Golgi apparatus?
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What structure within mitochondria increases the surface area for ATP production?
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Where in the plant cell does photosynthesis take place?
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What is the primary function of lysosomes?
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Which component of the cytoskeleton is responsible for providing structural support and aiding in cell division?
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What is the basic unit of life according to Cell Theory?
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Which type of cell lacks a nucleus?
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Which organelle is primarily responsible for energy production in eukaryotic cells?
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What feature is characteristic of eukaryotic cells but not found in prokaryotic cells?
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What structure in prokaryotic cells aids in movement?
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Which of the following components is found in both prokaryotic and eukaryotic cells?
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Eukaryotic cells often evolved from which type of cells?
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Which of the following structures is NOT typically found in prokaryotic cells?
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What is the primary function of the plasma membrane?
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Which characteristic describes phospholipids in the plasma membrane?
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What does selective permeability of the plasma membrane refer to?
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Which statement about the fluid mosaic model is true?
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What is contained within the structure of the plasma membrane?
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What is one impact of cell size on metabolism?
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Why is a high surface area to volume ratio beneficial for cells?
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What formula represents the surface area of a cuboidal cell?
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What happens to heat regulation in cells with a high SA:V ratio?
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How does cell size affect metabolic rates?
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What is the volume formula for a spherical cell?
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What is a consequence of having a low surface area to volume ratio?
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Which of the following statements is true regarding cell size?
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What is the primary component of the plant cell wall?
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What function does the cell wall provide for plant cells?
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How does the cell wall prevent plant cells from bursting in hypotonic environments?
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What additional components are found within the cell wall besides cellulose?
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What role does the cell wall play in the shape of plant cells?
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What effect does higher temperature have on membrane fluidity?
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Which type of fatty acids contribute to increased membrane fluidity?
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What role does cholesterol play at high temperatures regarding membrane fluidity?
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How do peripheral proteins primarily interact with the membrane?
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What function do membrane carbohydrates primarily serve?
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What does it mean that the plasma membrane is selectively permeable?
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In passive transport, what primarily drives the movement of molecules?
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Which statement accurately describes osmosis?
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What role do channel proteins play in facilitated diffusion?
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How do carrier proteins function in facilitated diffusion?
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What is the process called when a cell engulfs large particles like food or pathogens?
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Which type of endocytosis involves the intake of extracellular fluid and dissolved substances?
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What substance provides the energy necessary for active transport in cells?
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What occurs when ATP is broken down during the process of active transport?
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Which of the following processes involves specific molecules binding to receptors on the cell surface?
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What energy source is required for active transport?
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What is the primary function of the sodium-potassium pump?
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In a symport system, how do the substances move?
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What process is used by cells to expel materials using vesicles?
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What is the role of the proton pump in cellular processes?
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Study Notes
Cell Structure and Function
- Cells, the fundamental units of life, are responsible for all life processes.
- Cell Theory states that all living organisms are composed of one or more cells, the cell is the basic unit of life, and all cells arise from pre-existing cells.
- Prokaryotic cells are simpler and smaller, lacking a nucleus and membrane-bound organelles. Their DNA is located in a nucleoid region.
- Eukaryotic cells are more complex and larger, possessing a true nucleus and various membrane-bound organelles.
- Differences between prokaryotic and eukaryotic cells include the absence of a nucleus and membrane-bound organelles in prokaryotic cells.
- Prokaryotic cells include bacteria and archaea, while eukaryotic cells include plants, animals, fungi, and protists.
Cell Size
- Cell size impacts metabolism, surface area to volume ratio, and efficiency.
- Smaller cells have a higher surface area to volume ratio, allowing for more efficient exchange of materials.
- The surface area to volume ratio (SA:V) is a crucial concept that determines a cell's ability to exchange materials.
- A high SA:V ratio promotes efficient diffusion and metabolic activity.
- Cells can increase their SA:V ratio through microvilli, flattened shapes, and compartmentalization.
Plasma Membrane and Membrane Permeability
- The plasma membrane, also known as the cell membrane, surrounds the cell, protects it, and controls what enters and exits.
- It is composed of a phospholipid bilayer, proteins, and carbohydrates.
- Phospholipids form a bilayer, with hydrophilic heads facing outward and hydrophobic tails facing inward.
- The plasma membrane is selectively permeable.
- The fluid mosaic model describes the membrane as a fluid lipid bilayer with various proteins embedded within.
- Membrane fluidity is essential for proper membrane function and is influenced by temperature, fatty acid composition, and cholesterol.
- Membrane proteins can be integral or peripheral, with integral proteins spanning the entire membrane.
- Membrane carbohydrates attached to proteins (glycoproteins) or lipids (glycolipids) play roles in cell recognition and communication.
Plant Cell Walls
- Plant cells possess a cell wall in addition to the plasma membrane, providing structural support and protection.
- Composed primarily of cellulose.
- It maintains the shape of plant cells, prevents excessive water uptake, and provides rigidity.
Membrane Transport: Passive and Active Transport
- The plasma membrane regulates the movement of substances across it.
- Passive transport does not require energy, and includes simple diffusion, osmosis, and facilitated diffusion.
- Simple diffusion involves molecules moving from high concentration to low concentration.
- Osmosis specifically involves the movement of water across a semipermeable membrane from low solute concentration to high solute concentration.
- Facilitated diffusion utilizes protein channels or carriers to help larger or polar molecules cross the membrane.
- Active transport requires energy (ATP) to move substances against their concentration gradient.
- Pumps, like the sodium-potassium pump and proton pump, use ATP to move specific ions across the membrane.
- Cotransport involves the simultaneous movement of two substances across the membrane, either in the same direction (symport) or opposite directions (antiport).
- Exocytosis and endocytosis involve the use of vesicles to move materials into and out of the cell.
- Exocytosis releases materials from the cell by merging vesicles with the plasma membrane.
- Endocytosis involves the cell engulfing materials in vesicles formed from the plasma membrane, with three types: phagocytosis, pinocytosis, and receptor-mediated endocytosis.
How ATP Functions in Active Transport
- ATP provides the energy for active transport by releasing energy when broken down into ADP and a phosphate group.
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Description
Test your knowledge on the fundamental units of life with this quiz on cell structure and function. Explore key concepts such as cell theory, the differences between prokaryotic and eukaryotic cells, and the significance of cell size. Perfect for students studying biology!