Basic components of living systems

• What is the function and features of the nucleolus?

  Function: Ribosome production and assembly.

  Features: Dense region within the nucleus, contains DNA, RNA, and proteins.
• What is the function and features of the nucleus?

  Function: The nucleus controls the activities of the cell and contains the genetic material (DNA). Features: The nucleus is surrounded by a double membrane called a nuclear envelope, to protect it from damage and contains nuclear pores.
• What is the function and features of mitochondria?

  Function: Energy production. Where the final stages of respiration occur, where the energy stored in the bonds of organic molecules is made available for the cell to use by production of ATP.

  Features: Double membrane which is highly folded to form cristae and the fluid interior is called the matrix, mitochondrial DNA, contain enzymes and have the ability to self-replicate.
• What is the function and features of the vesicles?

  Function: Transport and store various substances within the cell. Features: Membrane-bound sacs, diverse in size and content, involved in intracellular transport and secretion.
• What is the function and features of the lysosomes?

  Function: Responsible for breaking down waste material in cells, including pathogens and programmed cell death.

  
  

  Features: Lysosomes are specialised forms of vesicles that contain hydrolytic enzymes.
• What is the function and features of the cytoskeleton?

  Function: Provides structural support, maintains cell shape, facilitates cell movement, and organizes cellular components.

  Features: Made up of microtubules, microfilaments, and intermediate filaments.
• What is the function and features of centrioles?

  Function: Centrioles are involved in cell division and help in the formation of the spindle fibers that separate chromosomes during mitosis. Found in the cytoskeleton. Features: Centrioles are cylindrical structures composed of microtubules arranged in a specific pattern. They are found in pairs near the nucleus of animal cells.
• What is the function and features of the flagella and cilia?

  Function: Movement or locomotion

  
  

  Features: Hair-like structures, found in various organisms, used for propulsion or creating currents.

  Each cilium contains two central microtubules surrounded by nine pairs of microtubules arranged like a wheel. Pairs of parallel microtubules slide over each other causing the cilia to move in a beating motion.
• What is the funtion and features of the rough endoplasmic recticulum?

  Function: Protein synthesis and modification.

  Features: Studded with ribosomes, interconnected network of tubules and flattened sacs, continuous with the nuclear envelope.
• What is the function and features of the smooth endoplasmic reticulum?

  Function: Lipid and carbohdrate synthesis and storage.

  Features: The ER is a network of membranes enclosing flattened sacs called cisternae. It is connected to the membrane of the nucleus.
• What is the fuction and features of the golgi apparatus?

  Function: Modifies, sorts, and packages proteins and lipids into vesicles for transport within or outside the cell.

  Features: It is a compact structure of cisternae and does not contain ribosomes.
• What is the definition of 'magnification'?

  How much bigger a sample appears to be under the microscope than it is in real life.
• What is the definition of 'resolution'?

  The ability to distinguish between two points on an image.
• What is the equation for magnification?

  Magnification = Image height / Actual height
• What is the resolution of a light microscope?


  200nm
• What is the resolution of the human eye?

  0.1mm
• How does a light microscope work?

  Light passes through the specimen, this image is magnified by multiple glass lenses.
• What are the advantages of light microscopes?

  • Cheap
  • Easy to use
  • Ability to study living tissues
  • Portable
• What are the disadvantages of a light microscope?

  • 2D images
  • Limited resolution of 200nm
  • Limited magnification of x2000
• How does a laser scanning microscope work?

  Uses a laser or high powered beam. The laser passes over each point in the specimen and creates an image over time.
• What are the advantages of electron microscopes?

  • Higher magnification of x500000
  • Higher resolution
• What are the disadvantages of electron microscopes?

  • Very expensive
  • Not easily transported
  • The preparation process causes damage to the specimen
• How does does a transmission electron microscope work and what is its resolution?

  A beam of electrons is transmitted through a specimen and focused to produce and image

  This has the best resolution with a resolving power of 0.5nm
• Describe a scanning microscope?

  A beam of electrons is sent across the surface of a specimen and the reflected electrons are collected.

  The resolving power is from 3-10nm, so the resolution is not as good but stunning 3D images of surfaces are produced, giving valuable information of the appearance of organisms.