Cell Structure and Function

1. Cell Structure and Function What makes up cells? What do cell do?

2. Levels of Organization • Organism • Organ System • Organ • Tissue • Cell

3. Cell Structure and Function Notes • Discovery of the Cell: • Mid 1600’s scientists began using microscopes to observe living things • Robert Hooke used microscope to observe thin slice of cork—dead plant material • Cork seemed to be made of box-like chambers—Hooke called cells • Anton van Leeuwenhoek discovered • living cells in pond water

4. Cell Theory: • All living things composed of cells • Cells are the basic unit of structure and function in living things • New cells are produced from existing cells

5. Cell and its Environment: • Organisms made of one cell—unicellular organisms • Ex: bacteria • Organisms made of many cells—multicellular organisms • Ex: plants, animals

6. Each cell must be in “balance” with its environment, exchange food, waste, H2O, CO2, O2 etc. • Process by which organisms maintain a relatively stable internal environment—homeostasis

7. Cell Parts and Functions Find out what all the organelles in a cell do and compare them to other items using analogies.

8. Cell Parts / Organelles • Organelle is a fancy name for specialized parts of a cell. It means “little organs”. • Plant and animal cells have many organelles, most of which they have in common.

9. Animal and Plant Cell

10. Organelles in Common • The following are organelles that both plants and animals can have: • Cell membrane • Nucleus • Nuclear membrane • Endoplasmic Reticulum • Ribosomes • Golgi Bodies • Vacuoles • Mitochondria • Chromatin • Cytoplasm

11. Organelles Vary by Cell • Plants usually also have cell walls and chloroplasts. • Animals may also have cilia, flagella, and lysosomes.

12. Cell Membrane • All cells have a cell membrane. • The cell membrane protects the contents of the cell and regulates passage of materials into and out of the cell. • The cell membrane is selectively permeable. This means that small molecules can slip through easily and that larger molecules are controlled as they pass in and out.

13. Cell membrane—determines what goes in and out of the cell

14. Selectively Permeable

15. A Cell Membrane is like… …your skin because they both protect internal parts and keep the whole together

16. Nucleus • The nucleus has two major functions: 1- it keeps all the genetic material DNA; 2- it controls all the functions in the cell including growth, metabolism, protein synthesis, and reproduction (cell division). • Only the cells of advanced organisms, known as eukaryotes, have a nucleus. Simpler one-celled organisms (prokaryotes), like the bacteria and cyanobacteria, don't have a nucleus. In these organisms, all of the cell's information is scattered throughout the cytoplasm.

17. Nucleus—control center of the cell • Double membranethat surrounds the nucleus—nuclear membrane • Hereditary information inside the nucleus—chromatin (DNA)

18. Cell Nucleus: • Organisms that do NOT have a distinct nucleus—prokaryotic(PRO rhymes with NO) • Ex: bacteria • Organisms with cells that have true nucleus and organelles—eukaryotic (EU rhymes with TRUE) • Ex: plants, animals, fungi

19. A Nucleus is like… … your brain because it controls your body like the nucleus controls the cell.

20. Nuclear Membrane • The nuclear membrane is a double layer that holds the nuclear material DNA inside and regulates the passage of materials into and out of the nucleus. • More than 20,000 ribosomes can be made by the nucleus in a minute and they need to be sent out into the cytoplasm through nuclear pores. • The ER is connected to the nuclear membrane.

21. A Nuclear Membrane is like… … your skull because it protects your brain like the nuclear membrane protects the nucleus.

22. Chromatin and Chromosomes • Chromatin is made up of chromosomes, which hold the genetic material: DNA!!!

23. Chromatin is like… …your brain cells because they are the genetic make up of your brain just like the DNA is the genetic make up of the cell.

24. Nucleolus • The nucleolus is inside the nucleus and it is where the ribosomes are made.

25. Nucleolus is like… …your ??? because...

26. Endoplasmic Reticulum • The endoplasmic reticulum manufactures, processes, and transports a wide variety of biochemical compounds for use inside and outside of the cell. • It also acts like a pipe between the nucleus and the cytoplasm. • There are two types of ER, rough ER (with ribosomes) and smooth ER (without ribosomes)

27. Rough Endoplasmic Reticulum (rough ER)— makes and transports proteins within the cell • Called rough ER because of the ribosomes found on its surface

28. Smooth Endoplasmic Reticulum (smooth ER)—makes and transport lipids and other materials within the cell • Called smooth ER because no ribosomes found on its surface

29. The Endoplasmic Reticulum is like… …your spinal cord because it is a pathway from the brain to the body which carries messages just like the ER carries messages from the nucleus to the cytoplasm.

30. Ribosomes • Ribosomes are the protein makers of the cell. • Proteins are necessary for all functions. They carry the messages that tell everything what to do and build. • Brain cells and pancreas cell have the most ribosomes because they are constantly making proteins.

31. Ribosomes—make proteins

32. The Ribosomes are like… …individual cells because they are responsible for building up your body just like ribosomes build up proteins.

33. Golgi Bodies • The Golgi Bodies are often considered the distribution and shipping department for the cell's chemical products. • The Golgi Bodies modify proteins and lipids (fats) that have been built in the endoplasmic reticulum and prepare them for export outside of the cell or for transport to other locations in the cell.

34. Golgi apparatus—processes and • packages proteins and other substances produced in the ER

35. The Golgi Bodies are like… …your digestive system because it transports materials outside the body like the golgi bodies transport things outside the cell.

36. Vacuoles • Vacuoles provide structural support, storage space, waste disposal, and also help in protection and growth. • Plant cell vacuoles are larger than animal cell vacuoles, and help to maintain the cell’s shape and structure.

37. Vacuoles—sac-like structures for storage • Plant cells usually contain a large vacuole that fills most of the cell—pressure from this large vacuole helps plants support themselves

38. The Vacuoles are like… …your fat cells because they store excess material and they provide the body with shape just like the vacuoles do for the cell.

39. Mitochondria • Mitochondria are the “powerhouse” of the cell. They convert oxygen and nutrients into adenosine triphosphate (ATP). • The process mitochondria use to make energy is called respiration.

40. Mitochondria—energy source of the cell (powerhouse)

41. The Mitochondria are like… …your intestines because they breakdown food to get energy out of it just like the mitochondria do to get ATP.

42. Cytoplasm • The cytoplasm is a jelly-like fluid that surrounds and cushions the organelles in the cell. • The cytoplasm also helps the cell maintain its shape.

43. Cytoplasm—gel-like medium that holds the organelles in position

44. Cytoskeleton—network of protein filaments (scaffolding) within the cytoplasm that helps cell maintain its shape

45. The Cytoplasm is like… …your skeletal system because it provides a structure and support for all internal organs just like cytoplasm provides a cushion and support for the cell.

46. Lysosomes • The main job of lysosomes is to digest materials no longer needed by the cell. • The process of recycling the cell's organic material is known as autophagy. Lysosomes break down cellular waste products, fats, carbohydrates, proteins, and other macromolecules into simple compounds, which are then transferred back into the cytoplasm as new cell-building materials. • Lysosomes are often made from the membrane of the golgi bodies.

47. Found in animal cells only: Lysosomes—cleans up the cell and digests unwanted materials

48. The Lysosomes are like… …the stomach because it uses acid to breakdown materials just like the lysosomes breakdown materials in the cell.

49. Cilia / Flagella • Cilia and flagella are present in most microorganisms and animals, but not in higher order plants. • The function of these parts is to allow for movement either of the cell itself or of something past the cell.

50. Cilia • The respiratory tract in humans is lined with cilia that keep inhaled dust, smog, and potentially harmful microorganisms from entering the lungs. Among other tasks, cilia also generate water currents to carry food and oxygen past the gills of clams and transport food through the digestive systems of snails.