Untitled Flashcards Set

Chapter 6, The Cell

1. Prokaryotic vs. Eukaryotic Cells

• Comparison: Prokaryotic cells are smaller, simpler, lack a nucleus and membrane-bound organelles. Eukaryotic cells are larger, more complex, and contain a nucleus and other membrane-bound organelles.

2. The Nucleus

• Structure: The nucleus is the control center, housing the cell's genetic material (DNA).

• Function: It regulates protein synthesis by transcribing DNA to mRNA, which moves to the cytoplasm for translation into proteins.

3. Ribosomes

• Structure: Composed of RNA and proteins.

• Function: Sites of protein synthesis where mRNA is translated into polypeptides (proteins).

4. Endomembrane System

• Components: Includes the nuclear envelope, endoplasmic reticulum (ER), Golgi apparatus, lysosomes, and plasma membrane.

• Functions: Modifies, packages, and transports lipids and proteins.

  • Relationships: The ER synthesizes proteins and lipids, while the Golgi apparatus modifies and sorts these for distribution.

5. Mitochondria

• Structure: Double membrane; smooth outer membrane and folded inner membrane (cristae).

• Function: Produces ATP through aerobic respiration, serving as the cell's powerhouse.

6. Chloroplasts

• Structure: Double-membraned with thylakoids and stroma.

• Function: Conducts photosynthesis, converting sunlight, water, and carbon dioxide into glucose and oxygen.

7. Cytoskeleton

• Function: Provides structural support, facilitates intracellular transport, and enables cell movement.

• Components: Composed of microtubules, actin microfilaments, and intermediate filaments, each with distinct roles.

8. Cytoskeletal Components

• Microtubules: Hollow tubes providing rigidity and transport tracks for organelles.

• Actin Microfilaments: Thin fibers involved in muscle contraction and cell shape alteration.

• Intermediate Filaments: Provide mechanical support and stabilize cell structures.

9. Plant Cell Walls vs. Extracellular Matrix (ECM) of Animal Cells

• Plant Cell Walls: Rigid, composed mainly of cellulose; provide structural support and define cell shape.

• Extracellular Matrix: Flexible network of proteins and polysaccharides in animal cells; supports cellular functions, communication, and attachment.

10. Intercellular Junctions

• Plant Cells: Plasmodesmata allow substance transport between cells.

• Animal Cells: Have tight junctions, anchoring junctions, and gap junctions for communication, adhesion, and transport between neighboring cells.