3.1-3.4 Key Terms Science Tita 2012-2013

  1. cell
    the basic unit of structure and function in a living thing
  2. cell theory
    a widely accepted explanation of the relationship between cells and living things
  3. unicellular
    made of a single cell
  4. multicellular
    consisting of many cells
  5. tissue
    a group of similar cells that perform the same function
  6. organ
    a structure in the body that is composed of different kinds of tissue
  7. organ system
    a group of organs that work together to perform a major function in the body
  8. organelle
    a tiny cell structure that carries out a specific function within a cell
  9. cell wall
    a rigid layer of nonliving material that surrounds the cells of plants and some other organisms
  10. cytoskeleton
    a protein "framework" inside a cell that gives the cell a shape
  11. cell membrane
    the outside cell boundary that controls which substances can enter or leave the cell
  12. nucleus
    the control center of a eukaryotic cell that directs the cell's activities and contains the information that determines the cell's form and function
  13. cytoplasm
    the material within a cell apart from the nucleus
  14. mitochondria
    rod-shaped cell structures that convert energy into food molecules to energy the cell can use to carry out its functions
  15. endoplasmic reticulum
    a cell structure that forms passageways in which proteins and other materials are carried through the cell
  16. ribosome
    a small grain-like structure in the cytoplasm of a cell where proteins are made
  17. Golgi body
    a structure in a cell that recieves proteins and other newly formed materials fromt eh endoplasmic reticulum, packages them, and distributes them to other parts of the cell
  18. chloroplast
    a structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food
  19. vacuole
    a sac inside the cell that acts as a storage area
  20. lysosome
    a small, round cell structure containing chemicals that break down large food particles into smaller ones
  21. element
    any substance that cannot be broken down into simpler substances
  22. compound
    two or more elements that are chemically combined
  23. carbohydrate
    an energy-rich organic compound made of the elements carbon, hydrogen, and oxygen
  24. protein
    large, organic molecules made of carbon, hydrogen, oxygen, nitrogen and sometimes sulfur
  25. amino acid
    a small molecule that is linked chemically to other amino acids to form proteins
  26. enzyme
    a protein that speeds up chemical reactions in a living thing
  27. lipid
    energy-rich organic compound, such as fat, oil, or wax, that is made of carbon, hydrogen, and oxygen
  28. nucleic acid
    a very large organic molecule made of carbon, oxygen, hydrogen, nitrogen, and phosphorus, that contain the instructions cells need to carry out all the functions of life
  29. DNA
    deoxyribonucleic acid; the genetic material that carries information about an organism and is passed down from parent to offspring
  30. RNA
    ribonucleic acid; a nucleic acid that plays an important role in the production of proteins
  31. selectively permeable
    a property of cell membranes that allows some substances to pass through, while others cannot
  32. diffusion
    the process by which molecules move from an area of high concentration to an area of lower concentration
  33. osmosis
    the diffusion of water molecules through a selectively permeable membrane
  34. passive transport
    the movement of materials through a cell membrane without using the cell's energy
  35. active transport
    the movement of materials through a cell membrane using energy
Card Set
3.1-3.4 Key Terms Science Tita 2012-2013
Vocabulary of sections 1-4