Cell types + subcellular structures

• What is the main focus of Lecture 2 in the 4BBY1030 Cell Biology & Neuroscience course?


  Cell types and subcellular structures
• What should students be able to explain by the end of Lecture 2?

  The concept of 'the cell'
• Which types of cells should students classify after Lecture 2?

  Prokaryotes, eukaryotes, bacteria, archaea, fungi, plants, animals
• What are the major features and organelles of eukaryotic cells that students should outline?

  • Plasma membrane
  • Nucleus
  • Rough and smooth endoplasmic reticulum
  • Golgi apparatus
  • Lysosomes and peroxisomes
  • Mitochondria and chloroplasts
  • Cytosol
  • Cytoskeleton
• How many cells approximately make up the human body?


  37 trillion cells
• Who is credited with the invention of the microscope?


  Robert Hooke
• What are the three main principles of the cell theory?

  1. All living organisms are made up of one or more cells.
  2. The cell is the basic unit of life.
  3. Cells arise from existing cells by division.
• Are all cells surrounded by a plasma membrane?


  True
• Do all cells contain a cell wall?


  False
• Do all cells contain genetic material in the form of DNA?


  True
• Do all cells contain DNA in a nucleus?

  False
• Do all cells perform metabolism?


  False
• Can all cells move?


  False
• What is the defining feature of prokaryotic cells?


  No nucleus
• What types of organisms are classified as prokaryotes?


  Bacteria and archaea
• What are cyanobacteria formerly known as?


  Blue-green algae
• What environments do many archaea species thrive in?


  Extreme environments
• What is the defining feature of eukaryotic cells?


  Presence of a nucleus
• What types of organisms are classified as eukaryotes?


  • Plants (including algae)
  • Animals
  • Fungi (molds, yeasts, mushrooms)
  • Protozoans
• What are the four main roles of the cell (plasma) membrane?

  1. Barrier
  2. Communication
  3. Import and export
  4. Electrical capacitor
• What is the composition of the cell membrane?


  Bilateral of phospholipids, cholesterol, and transmembrane proteins
• What does it mean for phospholipids to be amphipathic?


  They have a hydrophilic phosphate group and hydrophobic lipid tails
• What is the pH of the cytosol?


  Approximately 7.2
• What is the main function of the cytoskeleton?


  Maintenance of shape and stability
• What is the role of the nucleus in a cell?


  Site of RNA synthesis and processing
• What surrounds the nucleus?

  Nuclear envelope
• What is the function of the nucleolus?


  Site of ribosome synthesis
• What is the rough endoplasmic reticulum (rER) responsible for?


  Synthesis of secreted and transmembrane proteins
• What is the smooth endoplasmic reticulum (sER) responsible for?

  Synthesis of lipids and steroid hormones
• What is the Golgi apparatus composed of?


  Stack of flattened membrane vesicles
• What is the main function of the Golgi apparatus?


  Modification of proteins destined for secretion
• What is the shape of mitochondria?


  Often oval or sausage-shaped
• What is the function of mitochondria?


  Respiration and oxidative phosphorylation
• What is the role of lysosomes in a cell?

  Degrade unwanted proteins and particles
• What do peroxisomes degrade?


  Fatty acids and toxic compounds
• What enzyme neutralizes hydrogen peroxide in peroxisomes?


  Catalase
• What is the chemical reaction catalyzed by catalase?


  2 H$_2$O$_2$ → 2 H$_2$O + O$_2$
• What is the detoxification reaction involving ethanol in the liver?


  C$_2$H$_5$OH + H$_2$O$_2$ → CH$_3$CHO + 2 H$_2$O