Cellular Nature of Life Unit 4

1. Cellular Nature of LifeUnit 4 The cell is the smallest functional unit of life.

2. Unit 4: Key learning’s • The parts of a cell work in unison to maintain homeostasis within the cell. • Eukaryotic cells differ from Prokaryotic cells due to the presence of highly evolved organelles, designed to carry out advanced functions.

3. Unit 4: Essential question How do the parts of a cell work together to address the needs of a cell?

4. Unit 4: Concepts • Prokaryotes versus Eukaryotes (E) • Eukaryotic organelles (E) • Cell Diversity (C)

5. So how big are cells? Interactive cell sizes (click here)

6. Our understanding of cells can be summed up by the Cell Theory. • All living things are composed of one or more cells • Cells are the basic unit of structure and function. • All cells arise from existing cells.

7. All living things are composed • of one or more cells. • Some creatures are single celled –unicellular. • Some creatures exist in colonies with other unicellular creatures – colonial. • Some creatures exist with many cells that communicate, and share the responsibilities required for life – multicellular.

8. Essential question 1.1: How are each of the 5 essential cell parts used by cells?

9. I. All cells have 5 important features in common. • A cell membrane regulates what enters and leaves the cell. • Within the cell membrane, a thick gooey material known as cytoplasm suspends the organelles and contains the necessary building blocks for chemical reactions.. • A network of microtubules and microfilaments called the cytoskeleton provides for support and shape changing ability. • Nucleic acidsstore genetic information and regulate a cells activities. • Ribosomes read the nucleic acids to order amino acids into the necessary proteins.

10. The cytoskeleton of a eukaryotic cell.

11. II. Prokaryotic cells are more simple than Eukaryotic ones. • All prokaryotic cells are members of one of the two bacteria kingdoms (Eubacteria or Archaebacteria). • Prokaryotic cells contain the 5 essential cell parts and usually a cell wall. • Prokaryotic cells were the first to appear on Earth and continue to be the simplest cells.

12. II./2. Eukaryoticcells are more specialized than prokaryotes. • Often exist as parts of a multicellular organism (Protista, Fungi, Plants and Animals). • Highly specialized organelles provide these cells with more specialized functions. • It is believed that Eukaryotic cells may have formed from the combining of simpler prokaryotic cells. These remnants of bacteria life are now integral parts of our cells (mitochondria and chloroplasts).

13. Prokaryotic cell vs. Eukaryotic cell

14. VII. Some cells have an additional layer beyond the cell membrane called a cell wall. • Offers support to the cell. • Helps to regulate cell shape. • Walls are present in both prokaryotes (bacteria) and eukaryotes (fungi, protists, and plants). • Cell walls are often the point of attachment for ciliaand flagella.

15. A Gram Positive Cell Wall

16. Make sure you know that… All cells have 5 structures in common. They are 1. 2. 3. 4. 5. Many cells have a second outer layer known as the __________ __________

17. Essential question 2.1 & 2.2: How is the information in a cell organized? How are the parts of the endomembrane system related to one another?

18. XIII. Eukaryotic cells have a defined nucleus and many additional cell parts called organelles.

19. Question: Before we move ON!!!: What’s the difference between prokaryotic and eukaryotic cells? • Prokaryotes are simple cells that contain only the essential cell parts, and have no membrane bound organelles within their cell membrane (example: bacteria only). • Eukaryotes are complex cells that contain many membrane bound organellesthat carry out complex functions. (example: plants, animals, fungi, protists)

20. II. The nucleusdirects the activities of a eukaryotic cell. • Chromosomes made of DNA and proteins are located here. • Chromosomes are divided into genes coding for each trait (eye color, hitchhiker’s thumb, etc.). • RNA copies of genes leave the nucleus through nuclear pores.

21. Question 1: What is the function of the nucleus of a cell? It’s like the main office of a factory, where information is stored, and work orders arise. We’ll be developing a working analogy (drawing a comparison in order to show a similarity ) for how a cell is like a factory. Question 2 : How does information leave the nucleus if DNA is too large to exit the Nuclear Pores? RNA makes a copy of the DNA. RNA then leaves the nucleus through the nuclear pores. RNA is single stranded (smaller) and DNA is double stranded.

22. X. There are many organelles within Eukaryotic cells that are formed or surrounded by phospholipid bilayer. • Endoplasmic Reticulum • Golgi Apparatus • Vesicles • Lysosomes • Specialized Organelles

23. The phospholipids naturally arrange themselves into cells (spheres) due to its polar / non-polar interactions with water.

24. XI./1. The Endoplasmic reticulum (ER) is a system of tubes within the cell, that help to transport materials. • Rough ER is studded • with ribosomes. • B. RNA travels from the nucleus to the ribosomes(site of protein synthesis)then continues through the ER. • Newly formed proteins are pinched off the ER and form a • vesicle. • A Vesicleis used to transport materials out of the cell, or to a different location.

25. XI./2. The Golgi Apparatus is used for processing, packaging and secreting materials. • Proteins may arrive here after their creation in the ER. • Proteins may be processed in a way that alters their shape and functionality. • Proteins leave the Golgi in vesicles that may fuse with the cell membrane when materials need to exit the cell.

26. Proteins being processed by the Golgi Apparatus

27. XI./3. Lysosomes are sacs filled with digestive enzymes. • Formed when digestive enzymes are pinched off the Golgi. • Site of food digestion in the cell. • May be used to break down old, or non-functional cell parts.

28. Question: Lysosomes are common in Animals, Protists and Fungi, but are very rare in plants. Why is this the case? Plants normally produce their own food, and have no need for an organelle that functions in the breakdown of food particles.

29. Pair up!!! Describe three common cell parts • Describe their form and function in the cell 1 2 3 • If these were parts in a factory, what would they be?

30. Essential question 2.3: How are organelles used to produce and convert energy sources?

31. Activation: What type of energy conversion is occurring in each of these reactions? Energy can be heat, light, chemical, mechanical • Burning of wood • Combustion engine • Gasoline powered generator • Photosynthesis

32. XII. Mitochondriaare the power generators of both plant and animal cells. • Cells that require a lot of energy, like muscle cells, have thousands of Mitochondria. • Mitochondria are folded many times internally for extra surface area. • Convert carbohydrates into a useable form of energy called ATP.

33. XIII./4. Chloroplastshave a tremendous amount of internal surface area. This allows for the maximum number of energy producing reactions.

34. Question: What similarity do you see between mitochondria and chloroplasts?

35. XII./4. Since mitochondria carry their own DNA and ribosomes, Lynn Margulis proposed that they may have once been independent organisms. EndosymbioticTheory

36. Summarizer • Write down 1 similarity between the structure of a chloroplast and the mitochondria. • Describe the energy conversion that happens in a chloroplast. • Describe the energy conversion that happens in mitochondria. • Write a summary statement that covers both organelles. HAND IN BEFORE LEAVING

37. Essential question 3.1: How do the cells of each kingdom vary from one another?

38. I. Members of each kingdom can be identified by the presence of 4 common characteristics.

39. XIII. Plant cells have three distinguishing characteristics that are different than animal cells. • Organelles called chloroplasts use light energy to produce carbohydrates from CO2 and H2O. • Plants have a cell wall composed of cellulose. • Plants have large central vacuoles that are involved in storage of water, proteins and toxins.

40. Comparing plant and animal cells vs Using arrows and words identify a minimum of 5 differences

41. Endomembrane system How are the parts of the endomembrane system related to one another?

42. ER, Golgi, Vesicles and Cell Membrane are made of interchangeable parts(plb).

43. Question: Why is it important that ER, golgi, vesicles, lysosomes and the cell membrane are all made of phospholipid bilayer? This allows materials to be passed between them very easily.