There are two main types of cells:

• Prokaryotic: No membrane-bound organelles, they do not have nuclei.

  • Mainly in the archaea/bacteria kingdom

  • They respire anaerobically with enzymes in their cytoplasm, this is less efficient than aerobic respiration.

• Eukaryotic: They do have membrane-bound organelles.

  organelles

  → Sub cellular structures

  all cells: (prokaryotes, eukaryotes, and plant cells)

  • Cell membrane: Is semi-permeable, controlling what leaves and enters the cell. This maintains homeostasis.

  • Cytoplasm: Surrounds all other organelles and is the space in which the cellular metabolism is carried.

  • Ribosomes: They are responsible for protein synthesis, and they can be found free or attached to other organelles.

  only eukaryotes

  • Nucleus: Stores the genetic material of the cell, controls the cellular tasks, and decides the type of cell it will be.

  • Nucleolus: Produces ribosomes on the inside of the nucleus with Ribosomal RNA.

  • Vesicles: Sacs that work as containers. A vacuole is an example of a vesicle.

  • Golgi apparatus: Works as a packaging center. Receives molecules from the vesicles, it has enzymes that modify and sort them, and then it decides where they need to be sent. Including secretions like proteins and excretions like carbon dioxide.

  • Mitochondrion: Produces ATP, which is the energy needed for the cell to work appropriately. This is through cellular respiration.

    • Glucose + Oxygen → Carbon Dioxide + Water + ATP

  • Nuclear membrane: Has pores that allow the matter to enter and leave the genetic material in the nucleus.

  • Lysosome: Contains digestive enzymes for material that should be broken down or for apoptosis, which kills the cell when it becomes dangerous.

  • Centrioles: The position of this organelle within the cell determines where the other organelles are, and is fundamental for cell division.

  • Cytoskeleton: Provides structure and intracellular transportation, made up of a system of fibers in the cytoplasm.

  • Endoplasmic reticulum (ER)

    • Rough ER: This organelle has ribosomes attached to it. Thus, it is in charge of protein synthesis and its transportation.

    • Smooth ER: In charge of detoxification, and it produces lipids (for secondary energy source and insulation for the cell membrane) .

  only plant cells

  • Chloroplast Has chlorophyll, and performs photosynthesis.

  • Vacuoles: Although animal cells do have them but in a smaller size. It stores materials.

  • Cell wall: Additional to the cell membrane, simply maintains shape it is completely permeable.