cell structure

• Organelles students need to know the structure and function of for A-level biology

  • Cell surface membrane
  • Nucleus
  • Mitochondria
  • Chloroplasts
  • Golgi apparatus
  • Vesicles
  • Lysosomes
  • Ribosomes
  • Rough endoplasmic reticulum
  • Smooth endoplasmic reticulum
  • Cell wall
  • Cell vacuole
• Cell surface membrane


  Controls what can enter and exit the cell
• Nucleus


  Site of DNA replication and transcription, contains genetic information
• Nuclear envelope


  Double membrane with pores, contains nucleoplasm
• Nucleolus


  Site of rRNA production for ribosomes
• Endoplasmic reticulum (ER)


  Folded membranes, can be rough (with ribosomes) or smooth
• Rough ER


  Site of protein synthesis
• Smooth ER


  Site of lipid and carbohydrate synthesis and storage
• Golgi apparatus


  Folded membranes, produces vesicles for transport and modification of proteins and carbohydrates
• Golgi vesicles


  Carry finished products from Golgi to cell surface membrane for release
• Lysosomes


  Sacs of digestive enzymes that can break down pathogens, dead cells, and worn-out organelles
• Ribosomes


  Site of protein synthesis, come in two subunits (larger eukaryotic, smaller prokaryotic)
• Mitochondria


  Double membrane organelle, site of aerobic respiration
• Cristae


  Folded inner membrane of mitochondria
• Mitochondrial matrix


  Fluid-filled space within mitochondria
• Vacuoles


  Fluid-filled sacs that provide structural support, store sugars/amino acids, and contain pigments (in plants)
• Tonoplast


  Single membrane surrounding plant cell vacuole
• Chloroplasts


  Double membrane organelle, site of photosynthesis
• Thylakoid membranes


  Additional folded membranes within chloroplasts, site of light-dependent reactions
• Stroma


  Fluid-filled space within chloroplasts, contains enzymes for light-independent reactions
• Cell wall


  Provides structural strength, made of cellulose (plants) or chitin (fungi)
• Plasma membrane


  Phospholipid bilayer with embedded proteins, controls what enters and exits the cell
• Ribosomes are responsible for protein synthesis.
• The cytoplasm contains various structures such as ribosomes, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, cytoskeleton, and centrioles.
• Lysosomes contain digestive enzymes to break down waste materials.
• Mitochondria generate ATP through aerobic respiration.