Eukaryotic Cell Structure Quiz

• Eukaryotic Cell Wall:

  • Not all eukaryotes have a cell wall.
  • When present, structures vary by species and kingdom.
  • Composition varies, often containing cellulose (plants), chitin (fungi), or silica (diatoms).
  • Provides structural support and protection.
  • Regulates cell volume and shape.

• Cell Wall Structure (General):

  • Typically multi-layered.
  • Composed of various polysaccharides and proteins, depending on the organism.
  • Contains pores and channels to facilitate material transport.
  • Often has a rigid structure, providing mechanical strength and protection against osmotic stress.
  • May be a single or multiple layers.

• Organelles in Eukaryotes:

  • Nucleus: houses genetic material (DNA); controls cell activities.
  • Mitochondria: produce energy (ATP) via cellular respiration.
  • Endoplasmic Reticulum (ER): a network of membranes; involved in protein and lipid synthesis, transport.
  • Golgi apparatus: packages and modifies proteins and lipids.
  • Ribosomes: synthesize proteins.
  • Lysosomes: contain digestive enzymes; break down waste and cellular debris.
  • Vacuoles: storage organelles (water, nutrients, waste).
  • Chloroplasts (in plant cells): site of photosynthesis.
  • Cytoskeleton: provides structure and support; facilitates cell movement.
  • Peroxisomes: involved in various metabolic processes, including detoxification.

Eukaryotic vs. Prokaryotic Cells:

• Key Differences:
  • Eukaryotic cells have a membrane-bound nucleus and other membrane-bound organelles.
  • Prokaryotic cells lack a nucleus and other membrane-bound organelles.
  • Eukaryotic cells are generally larger than prokaryotic cells.
  • Eukaryotic cells have more complex cellular machinery compared to prokaryotic cells.
  • Eukaryotic DNA is organized into chromosomes; prokaryotic DNA is usually a single circular chromosome.
• Similarities:
  • Both have a cell membrane.
  • Both have ribosomes.
  • Both have genetic material (DNA).
  • Both carry out metabolic processes.
  • Both are capable of reproduction, albeit via different mechanisms.

Cell Membrane Functions:

• Selectively Permeable: Regulates the passage of substances into and out of the cell.
• Protection: Encloses the cell contents, acting as a barrier to harmful substances.
• Communication: Allows the cell to interact with its environment through receptors.
• Support: Contributes to the structural integrity of the cell.
• Transport: Facilitates movement of molecules across the membrane via various mechanisms (active and passive transport).
• Compartmentalization: Separates intracellular components into distinct compartments.

Plant vs. Animal Cells:

• Plant Cells:

  • Typically have a cell wall made of cellulose.
  • Possess chloroplasts for photosynthesis.
  • Often contain a large central vacuole.
  • Generally have a more rigid shape.

• Animal Cells:

  • Lacks a cell wall.
  • Lacks chloroplasts.
  • Has smaller and more varied vacuoles.
  • Tend to have a more flexible shape.

• Similarities:

  • Both have a plasma membrane.
  • Both have similar organelles (nucleus, mitochondria, ribosomes, etc.).
  • Both perform cellular functions.