Cell Structure: Subcellular Components

Cell Structure: Subcellular Components

Nucleus

  • Nucleus, often termed as ‘cell’s brain’, primarily contains the cell’s DNA and controls the cell activities.
  • Enclosed by a double-layered nuclear envelope with pores which allow material to move in/out.
  • Nucleolus is located within the nucleus and is responsible for producing ribosomes that move out of the nucleus to their positions on the rough endoplasmic reticulum where they are crucial in protein synthesis.

Mitochondria

  • Sometimes called the “powerhouse of the cell”, mitochondria are where the majority of ATP (adenosine triphosphate), the cell’s energy currency, is produced during the process known as cellular respiration.
  • Each has inner and outer membranes.

Endoplasmic Reticulum

  • Endoplasmic Reticulum (ER), a ‘protein factory’, is a network of flattened membranous sacs within the cell.
  • The Smooth ER is involved in lipid synthesis, while Rough ER, studded with ribosomes, is involved in protein synthesis.

Golgi Apparatus

  • Golgi apparatus, or ‘cell’s post office’, modifies, sorts, and packages different substances for transport to other parts of the cell or out of the cell.
  • Consists of a series of flattened stacked pouches called cisternae.

Ribosomes

  • Ribosomes, the ‘cell’s protein factories’, are the sites of protein synthesis.

Lysosomes

  • Lysosomes, or ‘cell’s recycle bin’, contain enzymes to digest waste materials and cellular debris.

Vacuoles

  • Vacuoles are storage sacs for water, food, or other cellular materials. In plant cells, the large central vacuole also contributes to structural support by maintaining turgor pressure against the cell wall.

Chloroplasts

  • Found only in plant cells, chloroplasts are where photosynthesis occurs.
  • These structures contain the photosynthetic pigment chlorophyll.

Cell Wall

  • Cell wall, found in plant cells, fungi, and certain prokaryotes, provides support and protection.
  • In plants, the cell wall is made of cellulose.

Cytoplasm

  • Cytoplasm consists of all the contents of a cell excluding the nucleus.
  • It’s the site where most of the cell’s metabolic reactions occur and contains many different organelles.

These are the most fundamental components of a cell, each performing distinct, intricate responsibilities governing cell structure and function.