Cell Structure and Function Quiz

Cell Structure and Function

• Cell Discovery: Robert Hooke discovered tiny chambers in a cork, naming them "cells" because they resembled cells in a monastery.
• Cell Principles: Cells are the basic unit of structure and organization in living things. All living things are composed of one or more cells. New cells are produced from existing cells, inheriting genetic material.
• Microscope Types:
  • Optical Microscope: Compound light microscopes use visible light, limited magnification.
  • Transmission Electron Microscope (TEM): Uses electrons to create a black and white image of non-living samples, offering high magnification (up to 500,000x).
  • Scanning Electron Microscope (SEM): Scans electrons on surface to create 3D black and white images of non-living samples, capable of being colorized, offering high magnification.
  • Scanning Probe Microscopy (SPM): Uses a physical probe to create images of surfaces.
  • Atomic Force Microscope (AFM): Measures forces between the probe tip and the surface to create 3D images.
• Cells (Prokaryote and Eukaryote):
  • All cells have a plasma membrane (controls what enters and leaves), genetic material (DNA), and processes to break down molecules for energy.
  • Prokaryotes: Lack a nucleus and membrane-bound organelles, are unicellular, and examples include bacteria.
  • Eukaryotes: Contain a nucleus and membrane-bound organelles, can be unicellular or multicellular, larger and more complex than prokaryotes.

Cell Membrane

• Structure: Selectively permeable lipid bilayer found in all plant and animal cells. Maintains internal balance.
• Function: Regulates substances entering and exiting the cell, and provides protection and support

Nucleus

• Function: Control center of the cell, housing DNA instructions for protein synthesis.
• Structure: Contains DNA bound to proteins to form long strands, surrounded by a nuclear envelope with pores (allowing material to move in and out).
• Nucleolus: Dense region inside the nucleus, involved in ribosome production.

Ribosomes

• Function: Synthesize proteins following DNA instructions from the nucleus.
• Structure: Smallest organelles, composed of RNA and proteins.
• Types: Free in the cytoplasm or attached to ER.

Endoplasmic Reticulum (ER)

• Function: Protein and enzyme production.
• Types:
  • Rough ER: Studded with ribosomes, involved in protein synthesis, modification, and export/transport.
  • Smooth ER: No ribosomes, produces cell membrane lipids, and contains enzymes for various functions.

Golgi Apparatus

• Function: Modifies, sorts, packages, and distributes proteins produced by the ER.

Lysosomes

• Function: Break down unwanted materials, including organelles that have lost their usefulness.
• Location: Primarily in animal cells but not always found in all animal cells
• Tay-Sachs Disease: A genetic condition caused by lysosomes that do not function properly resulting in "junk" buildup in the cell.

Vacuoles

• Function: Stores water, salts, and other materials in plant or animal cells but typically larger in plant cells.

Mitochondria

• Function: Converts stored food energy into a usable form (ATP); considered the powerhouse of the cell.
• Structure: Double membrane (outer and inner).

Chloroplasts

• Function: Captures sunlight energy and converts it into chemical energy; used in photosynthesis.
• Location: Plant cells only
• Structure: Double membrane.

Cilia and Flagella

• Function:
  • Cilia: Short, numerous projections, that resemble hairs, creating movement.
  • Flagella: Longer, less numerous projections, that propel cells.

Diffusion

• Definition: Net movement of particles from high to low concentration area.
• Factors affecting rate: Concentration, temperature, and pressure.

Passive Transport

• Definition: Does not use energy and moves substances down a concentration gradient
• Examples: Diffusion, facilitated diffusion (uses transport proteins), osmosis(water diffuses across membrane)

Active Transport

• Definition: Requires energy and moves substances against a concentration gradient
• Examples: ATPase pump

Solution Types

• Isotonic: Same concentration of solutes and water inside and outside the cell.
• Hypotonic: Lower concentration of solutes outside the cell, water moves into the cell.
• Hypertonic: Higher solute concentration outside the cell, water moves out of the cell..

Endocytosis and Exocytosis

• Endocytosis: A cell surrounds a substance in the outside environment and encloses it within a portion of the plasma membrane.
• Exocytosis: Secretion of materials at the plasma membrane.

Test your knowledge on cell discovery, principles, and different types of microscopes. Learn about the contributions of scientists like Robert Hooke and understand how cells are the fundamental units of life. Dive into the details of various microscopy techniques and their applications.