Overview of Cell Structure and Function

Sep 29, 2024

Review flashcards

BTEC Applied Science Unit 1: Biology - Cells

Introduction to Cells

  • Cells are the building blocks of living organisms.
  • Hierarchy of Biological Organization:
    • Cells form tissues.
    • Tissues form organs.
    • Organs form systems (e.g., digestive system).
    • Systems make up an organism.

Structure and Function of Animal Cells

  • Organelles: Different parts of a cell with specific functions.

Key Organelles and Their Functions

Plasma Membrane

  • Acts as the city wall of the cell.
  • Protects the cell and controls movement of substances in and out.

Cytoplasm

  • Jelly-like substance filling the cell.
  • Site for many chemical reactions.

Nucleus

  • The control center or town hall of the cell.
  • Surrounded by a double membrane with pores.

Nucleolus

  • Located inside the nucleus.
  • Dense DNA region; site of ribosome production.

Ribosomes

  • Protein factories of the cell.
  • Use DNA instructions to make proteins.
  • Eukaryotic cells have 80S ribosomes.
  • Prokaryotic cells have 70S ribosomes (simpler).

Rough Endoplasmic Reticulum (RER)

  • Flattened sacs with ribosomes; large surface area.
  • Site of protein synthesis.

Smooth Endoplasmic Reticulum (SER)

  • Tubular structures; site of lipid synthesis.

Vesicles

  • Small membrane-bound sacs.
  • Transport substances within the cell.

Golgi Apparatus

  • Modifies and packages proteins for transport.
  • Comparable to a post office.

Lysosomes

  • Enclosed by a single membrane.
  • Contain digestive enzymes; break down old organelles and pathogens.

Centrioles

  • Involved in cell division (mitosis).
  • Two hollow tubes at right angles; form spindle fibers.

Mitochondria

  • Power stations of the cell; site of respiration.
  • Produce ATP (adenosine triphosphate).
  • Double membrane with folded inner membrane.
  • Contains its own ribosomes (70S) and DNA, suggesting a symbiotic origin.

Key Points

  • Cells are fundamental to life and form the basis of larger biological structures.
  • Understanding cell organelles and their functions is crucial for studying biology.

Visual Identification

  • Ability to identify organelles in electron micrographs is important.

Review these notes to get a good overview of the structure and function of cells, particularly in understanding the roles of various organelles.