2.1-2.2-2.10-2.11-Cell-Structure-and-Function-Compartmentalization-1.pptx

Cell-Structure-and-Function-Compartmentalization

1. Unit 2 Cell Structure and Function

2. Unit 2: Cell Structure and Function Essential Questions: Defend the origin of eukaryotic cells How do the mechanisms for transport across membranes support energy conservation? What are the advantages and disadvantages of cellular compartmentalization? How are living systems affected by the presence or absence of subcellular components?

3. Starter: List as many parts of a cell as you can. Cell Structure and Function L/O: To describe the structure and function of subcellular components and organelles.

4. Cells Cells : the basic structural and functional units of every organism All cells : Are bound by a plasma membrane Contain cytosol Contain chromosomes Contain ribosomes L/O: To describe the structure and function of subcellular components and organelles.

5. Cells There are two types of cells: prokaryotes and eukaryotes Prokaryotes Eukaryotes Domains Bacteria and Archaea DNA is in the nucleoid region Generally smaller in size than eukaryotes Protists, fungi, animals, and plants DNA is in the nucleus Contain membrane bound organelles

6. Organelles

7. Organelles Organelles : membrane bound structures in eukaryotes Two classifications: Endomembrane organelles Nuclear envelope Endoplasmic reticulum Golgi complex Lysosomes Vesicles/Vacuoles Plasma membrane Energy organelles Mitochondria Chloroplasts

8. Compartmentalization Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. Compartmentalization in organelles allows for different metabolic reactions to occur in different locations Increases surface area for reactions to occur Prevents interfering reactions from occurring in the same location Topic 2.10 L/O: To describe the structure and/ or function of subcellular components and organelles

9. Unique Cell Components Plants Animals Chloroplasts Central vacuole Cell wall Plasmodesmata Lysosomes Centrosomes Flagella

10. Task: Cell Organelle Speed Dating Create a dating profile where you take on the persona of your assigned organelle. Create catchy pick-up lines based on your strengths and desires in a partner. Examples: I may be a cell wall, but I don’t want one between us. I don’t usually let people in, but I’d make an exception for you to be my cell- nificant other. On Tuesday we will speed date to find your PERFECT MATCH! L/O: To describe the structure and/ or function of subcellular components and organelles

11. Welcome to Speed Dating Things to consider as you search for a match: 1. What is their job within the cell and how does it relate to yours? 2. Do you all live in the same area (same type of cell)? 3. How do you work with this organelle to perform a cell’s basic function?

12. Endomembrane Organelles

13. Nucleus Contains chromosomes (genetic information) Enclosed by the nuclear envelope Double membrane Has pores Pores regulate entry and exit of materials from the cell

14. Nucleus Contains a nucleolus Dense region of the nucleus where ribosomal RNA ( rRNA ) is synthesized rRNA is combined with proteins to form large and small subunits of ribosomes Subunits exit via nuclear pores Assemble into ribosomes Ribosomes translate messages found on mRNA into the primary structure of polypeptides

15. Task 1: Review In order for DNA to leave the nucleus, it must first be transcribed by RNA polymerase into messenger RNA (mRNA). The mRNA transcript must then be modified before leaving the nucleus to the cytoplasm. In the cytoplasm, the ribosomes decode the information in mRNA and form continuous chains of amino acids, thus forming a protein. This process of DNA → RNA → protein is known as transcription and translation and will be the main concepts covered in Unit 6.  Answer questions 1-3. Think back to Unit 1, what are some differences between DNA and RNA? What are the monomers of proteins? What functional groups do they consist of? What are the structural levels of a protein?

16. Ribosomes Comprised of ribosomal RNA and protein Function : synthesize proteins Note : some texts do not classify ribosomes as organelles because they are not bound by a membrane L/O: To describe the structure and function of subcellular components and organelles.

17. Ribosomes Can be found in two locations: Cytosol Proteins produced here generally function only within the cytosol (i.e. enzymes ) Known as “free ribosomes” Bound to the endoplasmic reticulum or nuclear envelope Proteins produced here can be secreted from the cell Leave via transport vesicles

18. Endoplasmic Reticulum A network of membranous sacs and tubes Functions: Synthesizes membranes Compartmentalize the cell to keep proteins formed in the rough ER separate from those of free ribosomes

19. Endoplasmic Reticulum Two types: rough and smooth L/O: To describe the structure and/ or function of subcellular components and organelles

20. Endoplasmic Reticulum Rough ER Contains ribosomes bound to the ER membrane Smooth ER Contains no ribosomes Synthesizes lipids, metabolizes carbohydrates, and detoxifies the cell

21. Golgi Complex Contains flattened membrane-bound sacs called cisternae Separate the sacs from the cytosol Each cisternae is not connected Has directionality Cis face: Receives vesicles from the ER Trans face: Sends vesicles back out into cytosol to other locations or to the plasma membrane for secretion

22. Golgi Complex Functions: Receives transport vesicles with materials from the ER Modifies the materials Sorts the materials Adds molecular tags Packages materials into new transport vesicles that exit the membrane via exocytosis Ensures newly formed proteins are folded correctly or modified correctly

23. Lysosomes Membranous sac with hydrolytic enzymes Function: Hydrolyzes macromolecules in animal cells Autophagy : lysosomes can recycle their own cell’s organic materials Allows the cell to renew itself Peroxisomes Similar to lysosomes Membrane bound metabolic compartment Catalyze reactions that produce H 2 O 2 Enzymes in peroxisomes then break down H 2 O 2 to water

24. Vacuoles Large vesicles that stem from the ER and Golgi Selective in transport Types: Food vacuole Form via phagocytosis (cell eating) and then are digested by lysosomes Contractile vacuole Maintain water levels in cells Central vacuole Found in plants Contains inorganic ions and water Important for turgor pressure

25. Task 2: Practice FRQ Hepatitis C is a virus that attacks the liver and can cause liver disease. L iver disease has been linked to a reduction in albumin levels in patients analyzed. Albumin is an important protein in humans. It functions primarily to regulate oncotic pressure of blood, which is important for the regulation of fluids in vessels of the body and tissue repair. On average, patients with liver disease show a 10-30% decrease in blood-albumin levels. (a) Identify the organelle in liver cells that is most likely being affected by hepatitis C and (b) justify your reasoning. L/O: To explain how subcellular components and organelles contribute to the function of the cell.

26. Task 2: Practice FRQ In humans, pancreatic cells synthesize the protein insulin in the endoplasmic reticulum (ER). Patients diagnosed with type 1 diabetes have immune systems that mistakenly attack their pancreatic cells. Therefore, these patients cannot produce the hormone insulin and have to take medications to introduce insulin into their bodies. (a) Describe how insulin would be produced in a normal functioning (non-type 1 diabetes) pancreatic cell. L/O: To explain how subcellular components and organelles contribute to the function of the cell.

27. Sample Answer Hepatitis C is a virus that attacks the liver and can cause liver disease. L iver disease has been linked to a reduction in albumin levels in patients analyzed. Albumin is an important protein in humans. It functions primarily to regulate oncotic pressure of blood, which is important for the regulation of fluids in vessels of the body and tissue repair. On average, patients with liver disease show a 10-30% decrease in blood-albumin levels. (a) Identify the organelle in liver cells that is most likely being affected by hepatitis C and (b) justify your reasoning. Ribosomes are most likely being affect by Hepatitis C. Ribosomes carry out protein synthesis. Albumin is a protein synthesized by the liver. Since Hepatitis C causes a reduction of albumin production, it is likely affecting the ribosomes, which translate mRNA to an amino acid sequence. L/O: To explain how subcellular components and organelles contribute to the function of the cell.

28. Sample Answer In humans, pancreatic cells synthesize the protein insulin in the endoplasmic reticulum (ER). Patients diagnosed with type 1 diabetes have immune systems that mistakenly attack their pancreatic cells. Therefore, these patients cannot produce the hormone insulin and have to take medications to introduce insulin into their bodies. (a) Describe how insulin would be produced in a normal functioning (non-type 1 diabetes) pancreatic cell. In a normal functioning pancreatic cell, insulin would be produced at the ER and packaged into vesicles to be taken to the Golgi. At the Golgi, it would be modified. Once modified it would be released from the trans face of the Golgi via exocytosis. L/O: To explain how subcellular components and organelles contribute to the function of the cell.

29. Cell Structure and Function L/O: To describe the structure and function of subcellular components and organelles. Starter: A cell in a multicellular organism receives a signal to increase production of a transmembrane protein found in the cell membrane. Which of the following combinations of structures is expected to be directly involved in the process? Chloroplast, nucleus, mitochondria, lysosome Lysosome, mitochondria, Golgi complex, cytoskeleton Nucleus, ribosome, ER Golgi complex Nucleus , chloroplast, cytoskeleton, ribosome

30. Energy Organelles

31. Endosymbiotic Theory Endosymbiotic Theory : the theory that explains the similarities mitochondria and chloroplasts have to a prokaryote Theory states that organelles like mitochondria and chloroplasts were once free-living prokaryotic cells that began to live within a larger host cell. Prokaryotic cell became an endosymbiont (cell that lives in another cell) Became one functional organism Topic 2.11

32. Endosymbiotic Theory Evidence : Double membrane Ribosomes Circular DNA Capable of functioning on their own Topic 2.11

33. Mitochondria Site of cellular respiration Structure of the double membrane : Outer membrane is smooth Inner membrane has folds called cristae Divides the mitochondria into two internal compartments and increases the surface area

34. Mitochondria Intermembrane : space between inner and outer membrane Mitochondrial matrix : enclosed by inner membrane Location for the Krebs cycle Contains: Enzymes that catalyze cellular respiration and produce ATP Mitochondrial DNA Ribosomes

35. Mitochondria T he number of mitochondria in a cell correlates with metabolic activity Cells with high metabolic activity have more mitochondria Example: cells that move/contract

36. Chloroplast Specialized organelles in photosynthetic organisms Site of photosynthesis Contains the green pigment chlorophyll Inside of its double membrane: Thylakoids Membranous sacs that can organize into stacks called grana Light dependent reactions occur in grana

37. Chloroplast Stroma : fluid around thylakoids Location for the Calvin cycle Contains Chloroplast DNA Ribosomes Enzymes

38. The Cytoskeleton

39. Cytoskeleton A network of fibers throughout the cytoplasm Give structural support (especially for animal cells) and mechanical support : Anchor organelles Allow for movement of vesicles and organelles and/or the whole cell Movement occurs when the cytoskeleton interacts with motor proteins

40. Cytoskeleton There are 3 types of fibers in the cytoskeleton: Microtubules Microfilaments Intermediate filaments L/O: To explain how subcellular components and organelles contribute to the function of the cell.

41. Microtubules Hollow rod-like structures made of the protein tubulin Grow from the centrosome Assist in microtubule assembly L/O: To explain how subcellular components and organelles contribute to the function of the cell.

42. Microtubules Functions: Serve as structural support (think: tracks) for the movement of organelles that are interacting with motor proteins Assist in the separation of chromosomes during cell division Cell motility (i.e. cilia and flagella)

43. Microfilaments Thin solid rods made of the protein actin Functions: Maintain cell shape Bear tension Assist in muscle contraction and cell motility Actin works with another protein called myosin to cause a contraction Division of animal cells Contractile ring of the cleavage furrow

44. Intermediate Filaments Fibrous proteins made up of varying subunits Permanent structural elements of cells Functions: Maintain cell shape Anchor nucleus and organelles Form the nuclear lamina Lines the nuclear envelope

45. Which type of ER compartmentalizes the cell and which type of ER detoxifies the cell and synthesizes lipids? Describe the function of the Golgi complex. Where are hydrolytic enzymes found? What is their function? Describe the membrane structure of mitochondria. Task 1: Progress Check L/O: To describe the structure and function of subcellular components and organelles.

46. Task 1: Practice FRQ 5. You are working in a research lab and your goal is to determine the effect that alcohol has on the liver. You design an experiment where you expose samples of liver tissues to varying concentrations of alcohol as follows: Sample Concentration of alcohol Duration of exposure Sample 1 0.25 mg/mL 20 minutes Sample 2 0.35 mg/mL 20 minutes Sample 3 0.45 mg/mL 20 minutes After exposure to the alcohol, you analyze the liver samples. In all samples you find that the alcohol has been broken down (detoxified). However, in sample 3 you find damage to organelles has occured due to the high concentration of alcohol. (a) Identify one organelle in the liver that could be responsible for the detoxification of the alcohol in all three samples. (b) In sample 3 identify the organelle that would most likely be responsible for removing the damaged parts of organelles and (c) describe the steps it would take to do so.

47. Task 2: Cell structure and function MCQ practice. L/O: To explain how subcellular components and organelles contribute to the function of the cell.

48. Exam Review Working with a partner, go through the MCQs together to determine and discuss where you went wrong. As a class, we will go through the FRQs.

49. Cell Organelle Project Objective : Now that you have explored the structures found in eukaryotic cells, you will use your knowledge to create a project that highlights the functions of various organelles. Task : Your goal is to create a project that accurately and creatively depicts organelles in either an animal or plant cell. This is an open concept project, meaning you can decide what you want to create, as long as it meets the requirements listed in the rubric. Examples of projects include, but are not limited to: a 3D model (including a key with pictures), organelle baseball cards, an organelle family photo album, a catalogue selling organelles, a travel guide for a eukaryotic cell, FBI’s most wanted organelles, etc. Time to work on your project

50. Homework: AP Classroom MCQs 2.1 – 2.2 Campbell Biology pg. 93 – 120 (6.1-6.7) L/O: To explain how subcellular components and organelles contribute to the function of the cell.

51. Plenary Identify the three types of fibers found in the cytoskeleton. Name the types of fiber found in the cytoskeleton which maintains cell shape and forms the nuclear lamina. Describe the structure of microtubules. L/O: To explain how subcellular components and organelles contribute to the function of the cell.

52. Cell Organelle Project Objective : Now that you have explored the structures found in eukaryotic cells, you will use your knowledge to create a project that highlights the functions of various organelles. Task : September 8 th – Email project idea to teacher for approval September 25 th – Due for submission and presentations