Cell structure and function flashcards

Students must understand that all cells share certain features: a plasma membrane, cytoplasm, DNA, and ribosomes. Prokaryotic cells lack a membrane-bound nucleus and organelles, while eukaryotic cells contain a nucleus and specialized organelles. Each organelle has a specific structure tied to its function, such as the mitochondrion producing ATP through cellular respiration and the chloroplast capturing light energy. The endomembrane system coordinates synthesis and transport of proteins and lipids. Cell size is limited by the surface area-to-volume ratio. The fluid mosaic model describes the plasma membrane as a dynamic phospholipid bilayer with embedded proteins that regulate transport, communication, and recognition. Understanding how structure relates to function at the cellular level is central to all of AP Biology.

1. Card 1

   What is the key structural difference between prokaryotic and eukaryotic cells?

   Prokaryotic cells lack a membrane-bound nucleus and membrane-bound organelles; eukaryotic cells have both.

2. Card 2

   What is the function of the mitochondrion?

   The mitochondrion produces ATP through cellular respiration, using oxygen to break down glucose in its inner membrane and matrix.

3. Card 3

   What does the fluid mosaic model describe?

   The fluid mosaic model describes the plasma membrane as a flexible phospholipid bilayer with proteins, cholesterol, and carbohydrates embedded throughout.

4. Card 4

   Why does a cell's surface area-to-volume ratio limit cell size?

   As a cell grows, volume increases faster than surface area, reducing the surface area-to-volume ratio and limiting efficient exchange of materials.

5. Card 5

   What is the role of the rough endoplasmic reticulum?

   The rough ER is studded with ribosomes and synthesizes proteins destined for secretion, the membrane, or lysosomes.

6. Card 6

   How does the Golgi apparatus contribute to protein processing?

   The Golgi apparatus modifies, sorts, and packages proteins and lipids received from the ER, then ships them to their final destinations.

7. Card 7

   What is the function of lysosomes?

   Lysosomes contain hydrolytic enzymes that break down worn-out organelles, food particles, and foreign material inside the cell.

8. Card 8

   What structural feature of the mitochondrion increases its efficiency?

   The highly folded inner membrane (cristae) greatly increases surface area for the electron transport chain and ATP synthesis.

9. Card 9

   What is the function of the cytoskeleton?

   The cytoskeleton provides structural support, maintains cell shape, enables movement, and helps transport organelles within the cell.

10. Card 10

    How do chloroplasts and mitochondria support the endosymbiotic theory?

    Both organelles have double membranes, their own circular DNA, and ribosomes, suggesting they descended from free-living prokaryotes.

11. Card 11

    What is the function of the cell wall in plant cells?

    The cell wall made of cellulose provides structural support and protection, preventing the cell from bursting under osmotic pressure.

12. Card 12

    What role do ribosomes play, and where are they found?

    Ribosomes translate mRNA into protein; they are found free in the cytoplasm or bound to the rough ER in both prokaryotes and eukaryotes.

• Students often assume prokaryotes have no internal organization, but prokaryotes do have a plasma membrane, cytoplasm, ribosomes, and a nucleoid region containing DNA.
• A common error is treating the endomembrane system as a single organelle rather than a coordinated network including the ER, Golgi, vesicles, and plasma membrane.
• Students frequently confuse the cell wall with the plasma membrane, but only the plasma membrane controls what enters and exits the cell.

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