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Cell Structure and Organelles

≈ 20 min
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The cell is the basic structural and functional unit of life. Cells are studied under a microscope, and different organelles each do a specific job.

  • Cell (plasma) membrane - controls what enters and leaves the cell (selectively permeable).
  • Nucleus - contains DNA and controls all cell activities.
  • Mitochondria - carry out cellular respiration to release energy.
  • Ribosomes - the site of protein synthesis.
  • Endoplasmic reticulum and Golgi apparatus - transport and package substances.
  • Vacuole - stores cell sap; large and permanent in plant cells.

Plant cells have three extra structures: a cell wall (of cellulose, for support), chloroplasts (for photosynthesis), and a large central vacuole.

Which organelle is found only in plant cells and carries out photosynthesis?

Name the organelle that is the site of protein synthesis in a cell.

A cell measures 50 μm50\ \mu m across in real life. Under a microscope its image measures 5 mm5\ mm across. Calculate the magnification. (Hint: 5 mm=5000 μm5\ mm = 5000\ \mu m.)