W2 - CELL_PARTS_N_STRUCTURE.pptx for grade 7

cell organelles

1. HOUSE RULES 1 2 3 Always observe our health protocols. Turn off your phones . Using of phone during class hours is strictly prohibited. Violation of this rule is an automatic ground for phone confiscation. One speaker at a time . When someone is speaking, keep quiet and listen. If you want to say something, raise your hand and wait for your teacher to recognize you.

2. Obectives : 1. Identify the postulates of the cell theory 2. Explain the postulates of the cell theory 3. Identify the parts of plant cells and animal cells and state their functions 4. Differentiate plant and animal cell based on their organelle 5. Use proper techniques in observing and identifying the parts of a cell with a microscope such as the cell membrane, nucleus, cytoplasm, mitochondria, chloroplasts, and ribosomes

3. Obectives : 6. Describe the unicellular organism and a multicellular organism 7. Differentiate a unicellular organism from a multicellular organism 8. Describe prokaryotic cell and a eukaryotic cell; and 9. Recognize that some organisms consist of a single cell (unicellular) like in bacteria and some consist of many cells (multicellular) like in a human

4. CELL The Basic Unit Of Life

5. What is Cell? Cells are the basic structural and functional units of living organisms. In other words, cells make up living things and carry out activities that keep a living thing alive.

6. Cell Theory Cell theory is a collection of ideas and conclusions from many different scientists over time that describes cells and how cells operate. 1 2 3 All known living things are made up of one or more cells. All living cells arise from pre-existing cells by division. The cell is the basic unit of structure and function in all living organisms.

7. 1665 Cell Theory Timeline Robert Hooke Discovered cell 1674 Anton Van Leeuwenhoek Observed living cell 1883 Robert Brown Discovered nucleus

8. 1835 Felix Dujardin Discovered fluid content of cell 1838 Matthias Schleiden Proposed all plants are made up of cells 1839 J. E. Purkinje Named fluid content of cell as protoplasm Cell Theory Timeline

9. 1839 Theodor Schwann Proposed all animals are made up of cells 1845 Carl Heinrich Braun Proposed cell is the basic unit of life 1855 Rudolf Virchow Proposed all cells arise from pre-existing cells “OMNIS CELLULA E CELLULA” Cell Theory Timeline

10. THE SCIENTISTS BEHIND THE FORMULATION OF THE CELL THEORY Theodor Schwann Proposed all animals are made up of cells B. Matthias Schleiden Proposed all plants are made up of cells C. Rudolf Virchow Proposed all cells arise from pre-existing cells

11. _____ 1. Who was the first scientist to use the term “cell” after observing cork under a compound microscope? a. Rudolf Virchow b. Robert Hooke c. Anton van Leeuwenhoek d. Matthias Schleiden _____ 2. Which scientist is known as the “Father of Microbiology” for his detailed observations of living microorganisms using a simple microscope? a. Robert Hooke b. Anton van Leeuwenhoek c. Theodor Schwann d. Rudolf Virchow _____ 3. Which botanist concluded that all plants are made of cells ? a. Robert Hooke b. Anton van Leeuwenhoek c. Matthias Schleiden d. Theodor Schwann

12. ____ 4. Which scientist stated that all animals are made of cells , helping to complete the first two parts of the cell theory? a. Robert Hooke b. Theodor Schwann c. Rudolf Virchow d. Anton van Leeuwenhoek _____ 5. Who contributed to the cell theory by stating that all cells come from pre-existing cells ? a. Matthias Schleiden b. Robert Hooke c. Rudolf Virchow d. Theodor Schwann

13. Unicellular Organisms An organism that is made up of only one cell is called as unicellular organism. Euglena Paramecium Yeast

14. Multicellular Organisms An organism that is made up of more than one cell is called as multicellular organism. Plants Animals Fungus

15. Multicellular Organisms Under Microscope Leaf cells Muscle cells

16. Nucleus is undeveloped Only one chromosome is present Membrane-bound organelles are absent Examples: Bacteria and blue-green algae Nucleus is well developed More than one chromosomes are present Membrane bound organelles are present Examples: All other organisms Prokaryotic cell Eukaryotic cell

17. Size of Cells Cells vary in size. Most cells are very small (microscopic), some may be very large (macroscopic). The unit used to measure size of a cell is a micrometer. Smallest cell Mycoplasma Size: 0.1 µm Largest cell Ostrich egg Size: 18 cm 1 µm = 1/1000 millimeter

18. Size of Cells in Humans Smallest cell Sperm cell Largest cell Ovum cell Longest cell Nerve cell

19. Shape of Cells Cells vary in shape. Variation depends mainly upon the function of cells. Some cells like Euglena and Amoeba can change their shape, but most cells have a fixed shape. Human RBCs are circular biconcave for easy passage through human capillaries. Nerve cells are branched to conduct impulses from one point to another. Human WBCs can change their shape to engulf the microorganisms that enter the body.

20. Structure Of Cell The detailed structure of a cell has been studied under compound and electron microscopes. Certain structures can be seen only under an electron microscope. The structure of a cell as seen under an electron microscope is called ultrastructure. Compound microscope Magnification 2000X Electron microscope Magnification 500000X

21. 1 2 3 4 5 7 8 9 10 11 12 Animal Cell Nucleus Golgi body Vesicle Plasma membrane Mitochondria Cytoskeleton Centriole Lysosome Cytoplasm Rough endoplasmic reticulum Smooth endoplasmic reticulum Nucleolus 6

22. Plant Cell Nucleus Golgi body Vesicle Lysosome Plasma membrane Mitochondria Chloroplast Cell wall Vacuole Smooth endoplasmic reticulum Rough endoplasmic reticulum Nucleolus 1 2 3 4 5 12 11 10 9 6 7 8

23. Capsule Cell wall Plasma membrane Cytoplasm Flagellum Food granule Plasmid (DNA) Ribosomes Nucleoid Pili 1 2 4 9 8 7 3 5 6 10 Bacterial Cell

24. Structure Of Cell If we study a cell under a microscope, we would come across three features in almost every cell: plasma membrane, nucleus, and cytoplasm. All activities inside the cell and interactions of the cell with its environment are possible due to these features. Plasma Membrane Nucleus Cytoplasm Cytosol Cell Organelles Endoplasmic reticulum Golgi body Lysosomes Vacuoles Mitochondria Plastids Centrosome Cytoskeleton

25. Plasma Membrane Carbohydrates Proteins Lipids STRUCTURE: semi-permeable membrane Functions: Maintains the shape & size of the cell Regulates entry and exit of substances in and out of the cell

26. Cell wall Cellulose Plasma membrane Hemicellulose STRUCTURE: Non-living and outermost covering of a cell (plants & bacteria) Pectin Functions: It provides mechanical support and maintains cell shape in plant cell

27. STRUCTURES: Dense spherical body located near the center of the cell FUNCTION: It is the control center of the cell as it directs and coordinates all cellular activities. Nucleus Nucleus

28. Jelly-like material formed by 80 % of water that fills the cell. Present between the plasma membrane and the nucleus Contains a clear liquid portion called cytosol and various particles Also contains many organelles with distinct structure and function Some of these organelles are visible only under an electron microscope Cytoplasm Organelles Cytoplasm

29. Endoplasmic Reticulum Rough ER Ribosomes STRUCTURE: smooth(lacks ribosomes) and rough(studded with ribosomes) FUNCTION: RER synthesizes secretory proteins and membrane proteins SER synthesizes lipids for cell membrane Smooth ER

30. Trans face STRUCTURES: Formed by stacks of 5-8 membranous sacs Sacs are usually flattened and are called the cisternae Has two ends: cis face situated near the endoplasmic reticulum and trans face situated near the cell membrane Functions: Modifies, sorts, and packs materials synthesized in the cell Cis face Cisternae Lumen Incoming transport vesicle Outgoing transport vesicle Newly forming vesicle Golgi body

31. Golgi Body At Work Smooth ER Nucleus Rough ER Plasma membrane Golgi body Vesicles Lysosomes

32. STRUCTURES: Small, spherical, single membrane sac It is referred to as the “ SUICIDE BAG” of the cell Functions: Help in digesting large molecules Protect cells by destroying foreign invaders like bacteria and viruses Degradation of worn-out organelles In dead cells perform autolysis Lysosomes Membrane Hydrolytic enzymes

33. STRUCTURES: Single membrane sac filled with liquid or sap (water, sugar, and ions) In animal cells, vacuoles are temporary, small in size, and few in number In plant cells, vacuoles are large and more in number Functions: Store various substances including water, food, or waste for the cells. Vacuoles Vacuole Tonoplast

34. STRUCTURES: Small, rod-shaped organelles bounded by two membranes - inner and outer It is also known as “ Powerhouse of the Cell” Functions: It provides energy for the cell in the form of adenosine triphosphate (ATP) Mitochondria Outer membrane Inner membrane Ribosomes Matrix DNA Cristae

35. Plastids Plastids are double membrane-bound organelles found inside plants and some algae. They are responsible for activities related to making and storing food. They often contain different types of pigments that can change the colour of the cell.

36. Chromoplasts Chromoplasts are plastids that produce and store pigments They are responsible for the different colors found in leaves, fruits, flowers and vegetables. Carrot Pigment: Carotene Mango Pigment: Xanthophyll Tomato Pigment: Lycopene

37. Leucoplasts Leucoplasts are colorless plastids that store foods. They are found in storage organs such as fruits, tubers, and seeds. Potato tubers Food: Starch Maize grains Food: Protein Castor seeds Food: Oil

38. STRUCTURE: It is a double-membrane structure that contains chlorophyll pigments. Functions: convert light energy into chemical energy in the form of food Provide green color to leaves, stems, and vegetables Chloroplasts Stroma Granum Inner membrane Outer membrane Thylakoid

39. STRUCTURES: Centrioles are hollow, cylindrical structures made of microtubules Function: Form spindle fibers which help in the movement of chromosomes during cell division Centrioles Centrosome matrix Centrioles Microtubules

40. STRUCTURE: Network fibers that are scattered throughout the cytoplasm, interconnecting some organelles. Functions: Determine the shape of the cell Give structural strength to the cell Responsible for cellular movements Cytoskeleton Cell membrane Microtubules Microfilaments

41. Generally small in size Cell wall is absent Plastids are absent Vacuoles are smaller in size and less in number Centrioles are present Generally large in size Cell wall is present Plastids are present Vacuoles are larger in size and more in number Centrioles are absent Animal cell Plant cell

42. I II _____ 1. it serves as Storage tanks for food, water, or waste a. Ribosomes _____ 2. it is know as Suicide Bag b. Golgi Body _____ 3. Control center of the cell c. Vacuoles _____ 4. Protein Factory of the cell d. Plasma Membrane _____ 5. Regulates entry and exit of substances in and out of the cell e. Cytoskeleton _____6. it gives structural support to the cell f. Mitochondrion _____7. the powerhouse of the cell. g. Lysosomes _____8. Modifies, sorts, and packs materials synthesized in the cell h. Nucleus

43. THANK YOU...