Cell Structure Quiz

Study Notes

Cell Structure

Cells are the basic structural and functional units of all living organisms.
All cells are enclosed by a plasma membrane, a selectively permeable barrier that regulates the passage of materials in and out of the cell.
Prokaryotic cells (bacteria and archaea) lack a nucleus and other membrane-bound organelles.
Eukaryotic cells (plants, animals, fungi, and protists) possess a nucleus and other membrane-bound organelles.
Key components of the cell structure:
- Cell membrane: A phospholipid bilayer with embedded proteins, controlling what enters and exits the cell.
- Cytoplasm: The jelly-like substance filling the cell.
- Nucleus: Containing the cell's DNA, the control center of the cell.
- Ribosomes: The sites of protein synthesis.
- Endoplasmic Reticulum (ER): Involved in protein and lipid synthesis.
- Golgi apparatus: Modifies, sorts, and packages proteins.
- Mitochondria: The powerhouses of the cell, generating energy (ATP) through cellular respiration.
- Lysosomes: Contain enzymes that break down waste and cellular debris.
- Vacuoles: Storage sacs for water, nutrients, or waste products.
- Cytoskeleton: Provides structural support and facilitates movement within the cell.
- Cell wall: A rigid layer surrounding some cells (plants, fungi, bacteria) providing support and protection.

Cell Function

Cells perform various essential functions that sustain life.
Metabolism: All chemical reactions within a cell, including energy production and consumption.
Transport: Movement of materials across the cell membrane (passive and active).
Secretion: Release of substances from the cell.
Communication: Cells interact with each other and their environment.
Growth and repair: Cells increase in size and replace damaged cells.
Reproduction: Cells undergo division to produce new cells.
Different cell types specialize in different functions.

Cell Division

Cell division is essential for growth, repair, and reproduction.
Mitosis: A process where a single cell divides into two identical daughter cells. Crucial for growth and repair.
Meiosis: A type of cell division for sexual reproduction, producing haploid gametes.
Key phases of mitosis include:
- Prophase, metaphase, anaphase and telophase.
Cytokinesis: The physical division of the cytoplasm, completing cell division.

Cell Communication

Cells communicate with each other through various mechanisms.
Signaling molecules: Chemical signals that cells use to communicate with each other.
Receptors: Proteins on the surface of cells that bind to signaling molecules.
Intracellular signaling pathways: Cascades of molecular events that transmit the signal within the cell.
Different types of cellular communication occur.
- Direct contact (e.g., cell junctions).
- Local signaling (e.g., paracrine and synaptic signaling).
- Long-distance signaling (e.g., hormonal signaling).

Cell Types

Cells vary greatly in structure and function.
Nerve cells (neurons): Specialized for transmitting electrical signals.
Muscle cells: Specialized for contraction.
Epithelial cells: Cover surfaces of the body.
Connective tissue cells: Support and connect other tissues.
Blood cells: Transport oxygen.
Plant cells: Possess chloroplasts for photosynthesis and a cell wall.
Specialized cells within tissues, organs, and organ systems have unique structures and functions appropriate to their roles.
Specialized cells often have unique features that allow them to perform specific functions.

Description

Test your knowledge on cell structure and function with this quiz. Explore key components such as the cell membrane, nucleus, and organelles in both prokaryotic and eukaryotic cells. Understand the roles these structures play in the life of an organism.