Cells

• Cell Wall:

  • Function: Provides structural support and protection to the cell. It also helps maintain the shape of the cell and prevents it from bursting when water enters the cell. The cell wall is primarily found in plant cells, fungi, bacteria, and some protists.
• Cell Membrane:

  • Function: Regulates the movement of substances in and out of the cell. It acts as a selective barrier, allowing only certain molecules to enter or exit the cell, while maintaining the internal environment of the cell. The cell membrane is present in all cells.
• Chloroplast:

  • Function: Responsible for photosynthesis in plant cells and some protists. Chloroplasts contain the pigment chlorophyll, which captures light energy and converts it into chemical energy in the form of glucose, using carbon dioxide and water.
• Vacuole:

  • Function: Stores nutrients, waste products, and other materials needed by the cell. In plant cells, the central vacuole also helps maintain turgor pressure, which keeps the plant upright and supports growth. In some animal cells, vacuoles are smaller and play a role in storage and transport.
• • Nucleus:
  • Function: Acts as the control center of the cell, containing the cell's genetic material (DNA). It regulates cell growth, metabolism, and reproduction by controlling gene expression. The nucleus is surrounded by a nuclear membrane, which separates it from the cytoplasm.
• Mitochondrion:

  • Function: Known as the powerhouse of the cell, mitochondria generate energy in the form of adenosine triphosphate (ATP) through the process of cellular respiration. They are crucial for energy production in eukaryotic cells
• Cell Wall

  • Plant Cells: Have a rigid cell wall made of cellulose that provides structural support, protection, and helps maintain the shape of the cell.
  • Animal Cells: Do not have a cell wall. Instead, they have only a cell membrane, which provides flexibility and allows for a variety of shapes.
• Cell Membrane

  • Plant Cells: Present inside the cell wall, controlling the movement of substances in and out of the cell.
  • Animal Cells: Present as the outermost layer, providing a flexible boundary that regulates the exchange of substances.
• Chloroplasts

  • Plant Cells: Contain chloroplasts that carry out photosynthesis, converting light energy into chemical energy (glucose).
  • Animal Cells: Do not have chloroplasts because they do not perform photosynthesis
• Vacuoles

  • Plant Cells: Usually have a large central vacuole that occupies most of the cell’s volume. It stores water, nutrients, and waste products, and helps maintain turgor pressure, which keeps the plant upright.
  • Animal Cells: May have small, multiple vacuoles that are primarily involved in storage and transport of materials within the cell.
• Nucleus

  • Both Plant and Animal Cells: Have a nucleus that contains genetic material (DNA) and regulates cell activities, such as growth, metabolism, and reproduction. The nucleus is surrounded by a nuclear envelope.
• Mitochondria

  • Both Plant and Animal Cells: Contain mitochondria, the powerhouses of the cell, where cellular respiration occurs to produce ATP, the energy currency of the cell.
• Cell Wall: A rigid outer layer found in plant cells, fungi, and some bacteria, providing structural support, protection, and determining the shape of the cell. It is primarily made of cellulose in plants.
• Cell Membrane: A flexible, semi-permeable membrane that surrounds the cytoplasm of all cells, controlling the movement of substances in and out of the cell. It is composed mainly of a lipid bilayer with embedded proteins.
• Chloroplast: An organelle found in plant cells and some algae that contains chlorophyll and is responsible for photosynthesis, the process by which light energy is converted into chemical energy in the form of glucose.
• • Vacuole: A membrane-bound organelle found in plant and fungal cells, as well as some protists and animal cells, that stores nutrients, waste products, and other substances. In plant cells, the central vacuole also helps maintain cell turgor pressure.
• Nucleus: A membrane-bound organelle found in eukaryotic cells that contains the cell's genetic material (DNA). The nucleus controls cellular activities, including growth, metabolism, and reproduction, through the regulation of gene expression.
• Mitochondrion: A double-membraned organelle found in most eukaryotic cells, often referred to as the "powerhouse" of the cell. It generates energy in the form of ATP through the process of cellular respiration.
• Cytoplasm: The gel-like substance inside the cell membrane, excluding the nucleus, that contains all the organelles and is the site for most cellular processes. It is composed mainly of water, salts, and proteins.
• What are the basic units of life?

  Cells
• What will you learn in this topic about cells?

  • Producing scientific drawings
  • Interpreting observations through standard units
  • Structure of the cell revealed with technology
  • Preparing a wet mount and investigation method
  • Pointing and focusing a light microscope
  • Calculating magnification and size of cells
  • Cell biology and light microscopy
  • Structure and function of plant cells
  • Applying basic methods in investigations
  • Structure and function of the nucleus and cytoplasm
  • Measuring different cell organelles
  • Interactions and diffusion of materials
  • Drawing a typical book of cells
  • Similarities and differences between plant and animal cells
• What is the typical diameter of an animal cell?

  10 to 20 μm
• Why were cells invisible to simple lens microscopes?

  Because they are smaller than the smallest thing visible to the naked eye
• What invention allowed scientists to discover the internal structures of cells?

  The light microscope
• When did good light microscopes become available?

  In the early 1900s
• What did the development of the electron microscope in 1940 allow scientists to do?

  It required new techniques to learn more about cells
• What tools are needed for investigating the invisible world?

  • Hand lenses
  • Microscopes
• How do microscopes magnify images?

  By using convex lenses that concentrate light
• What is magnification?

  How larger the image is than the actual object
• What types of microscopes are there?

  Monocular and binocular compound microscopes
• What is a dissecting microscope?

  A low-resolution compound microscope
• What do scanning and transmission electron microscopes use to magnify?

  Electrical and magnetic fields
• Who designed the first single-lens microscope?

  Antonie van Leeuwenhoek
• What was the magnification of Antonie van Leeuwenhoek's microscope?

  270 x
• Who was the first scientist to use the word 'cells'?

  Robert Hooke
• What did Robert Hooke describe when he used the term 'cells'?

  Tiny hollow compartments in cork
• What does the cell theory state?

  All living organisms are made of cells
• What are the main points of the cell theory?

  • All living organisms are made of cells (unicellular or multicellular)
  • The cell is the smallest unit of life
  • All cells come from pre-existing cells
• What does modern cell theory include beyond the original theory?

  Energy flows inside cells and heredity information is passed on
• What is a micrograph?

  A photograph taken through a microscope