Biology for Human Movement & Nutritional Sciences - Eukaryotic Cells Lecture Notes

Module Overview

• Lecture Series:
  • Lecture 1: Life and cells
  • Explores similarities and differences of life forms.
  • Lecture 2: Eukaryotic cells (Focus of this lecture)
  • Discusses organelles and components of eukaryotic cells.
  • Lecture 3: Prokaryotic cells
  • Lecture 4: Water, concentrations, acids, and bases.
  • Lecture 5: Carbon and macromolecules.
  • Lecture 6: Cell membrane structure and function.

Learning Goals

• After today, you will be able to:
  • Describe functions of organelles and cell components in eukaryotic cells.

Key Concepts and Readings (from Campbell Biology)

1. Microscopy and Biochemistry : Used to study cells (sec. 6.1, p. 96)
2. Eukaryotic Cells : Characterized by internal membranes that compartmentalize functions (sec. 6.2, p. 99)
3. Genetic Instructions : Housed in the nucleus, carried out by ribosomes (sec. 6.3, p. 104)
4. Endomembrane System : Regulates protein traffic and metabolic functions (sec. 6.4, p. 106)
5. Mitochondria and Chloroplasts : Change energy forms (sec. 6.5, p. 110)
6. Cytoskeleton : A network of fibers organizing structures and activities (sec. 6.6, p. 114)
7. Extracellular Components : Coordinate cellular activities (sec. 6.7, p. 120)
8. Holistic View of Cells : A cell is greater than the sum of its parts (sec. 6.8, p. 123)

Overview of Eukaryotic Cells

• Eukaryotic 'animal' and 'plant' cells both contain specialized compartments.

Eukaryotic Cell Features

• Cell as a City Analogue:
  • Nucleus: Library (containing DNA)
  • Ribosomes: Factories (for protein synthesis)
  • Rough ER: Major organelle for protein synthesis, modifies proteins.
  • Smooth ER: Synthesizes lipids and detoxifies drugs.
  • Golgi Apparatus: Post office/distribution center for proteins.
  • Mitochondria: Power plants (energy production).
  • Lysosomes: Waste management and recycling (digestion).

Nucleus

• Structure:
  • Surrounded by double nuclear membrane with pores (controlled access).
  • Interior contains DNA and protein (chromatin).
• Function:
  • Houses genetic information.
  • Nucleolus assembles ribosome units.

Ribosomes

• Function:
  • Sites of protein synthesis; translate mRNA into protein.
  • Found free in cytoplasm or attached to Rough ER.
  • Composed of a large and small subunit, assembled in the nucleolus.

Endoplasmic Reticulum (ER)

• Rough ER:

  • Covered with ribosomes; primary site for protein synthesis.
  • Proteins modified with sugars/phosphates.
  • Example: formation of glycoproteins like ABO blood group markers.

• Smooth ER:

  • Synthesizes lipids; no ribosomes attached.
  • Detoxifies drugs in liver cells.

Golgi Apparatus

• Function:
  • Modifies, sorts, and packages proteins and lipids from the ER for secretion or delivery to other organelles.

Mitochondria

• Function:
  • Site of cellular respiration (energy production).
  • Double membrane structure with inner folds (cristae) to increase surface area.
  • Equation of cellular respiration:
    C6H{12}O6 (glucose) + 6O2 (oxygen) \rightarrow 6CO2 (carbon dioxide) + 6H2O (water) + ATP

Chloroplasts

• Function:
  • Site of photosynthesis in plants (contains chlorophyll).
  • Double membrane structure with thylakoids for energy transduction.

Cytoskeleton

• Components:
  • Microtubules, intermediate filaments, microfilaments.
• Function:
  • Provides support, shape, and facilitates movement.
  • Enables dynamic behavior like cell shape changes.

Vacuoles in Plant Cells

• Functions:
  • Store water, enzymes, and ions; maintain turgor pressure.
  • Support chloroplast positioning for optimal light exposure.

Extracellular Structures

• Cell Wall:
  • Unique to plants and fungi; provides mechanical support.
  • Composed of polysaccharides (cellulose in plants).

Summary of Lecture

• You learned to describe the functions of:
  1. Nucleus
  2. Nucleolus
  3. Ribosome
  4. Endoplasmic reticulum
  5. Golgi apparatus
  6. Mitochondrion
  7. Chloroplast
  8. Vacuole
  9. Cytoskeleton
  10. Cell wall