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Explore the history of cell discovery, learn about the different types of cells, and understand the theories that explain their structure and function.
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Chapter 7 Cellular Structure & Function
Chapter 7 Vocabulary Word, Definition, Sentence, Picture (Worth 136 pts) active transport cell cell theory centriole chloroplast cilium cytoplasm cytoskeleton diffusion dynamic equilibrium Endocytosis endoplasmic reticulum eukaryotic cell exocytosis facilitated diffusion Flagellum fluid mosaic model Golgi apparatus hypertonic solution hypotonic solution isotonic solution lysosome mitochondrion nucleolus nucleus organelle osmosis phospholipid bilayer plasma membrane prokaryotic cell ribosome selective permeability transport protein vacuole
9/13—9/17 Daily Warm Up What is the basic type of microscope used to view cells and processes such as mitosis and meiosis? Compound Light Microscope List the two types of cells. One type of cell has two sub-groups, name them as well. Prokaryotic Eukaryotic Animal Plant
9/13-9/17 Daily Warm Up What is a cell? The basic structural and functional unit of all living organisms. Hypothesize the difference between eukaryotic and prokaryotic cells. Organelles separate the 2 from each other.
9/13-9/17 Daily Warm Up What are the 3 theories in the cell theory? 1. All living organisms are composed of 1 or more cells. 2. Cells are the basic unit of structure in an organism. 3. Cells can only arise from pre-existing cells. If you were trying to observe the water vacuoles in a plant cell, which microscope would you use? Compound Light
9/13-9/17 Daily Warm Up Thursday no warm up
9/13-9/17 Daily Warm Up What is the theory that states that prokaryotic cells further developed eukaryotic cells? Endosymbiotic theory What are the names of the two electron microscopes? (Give abbreviations) TEM-Transmission Electron Microscope SEM-Scanning Electron Microscope
Chapter 7 Opening Activity • Words you can use: • Animals • bacteria • chloroplasts • Eukaryotes • a large central vacuole • plants • plasma membrane • prokaryotes All cells have a: And are grouped into two broad categories: Which are mainly: Some contain yeast and algae Which contains unique structures such as: Cell walls
Section 1 Cell Discovery & Theory
Chapter 7 Opening Activity • Words you can use: • Animals • bacteria • chloroplasts • Eukaryotes • a large central vacuole • plants • plasma membrane • prokaryotes All cells have a: Plasma membrane And are grouped into two broad categories: prokaryotes eukaryotic Which are mainly: bacteria plants animals Some contain yeast and algae Which contains unique structures such as: Cell walls chloroplasts A large central vacuole
History of the Cell Theory • A cell is the basic structural and functional unit of all living things. • The first to observe cells was Robert Hooke, who made a simple microscope, and looked at a piece of cork. • Cork= the dead cells of Oak bark • Later, Anton van Leeuwenhoek advanced Hooke’s findings and developed an even better microscope called a light microscope.
The Cell Theory Observations from Schleiden, Schwann & Virchow summarized the theory of the cell. 1. All living organisms are composed of 1 or more cells. 2. Cells are the basic unit of structure in an organism. 3. Cells can only arise from pre-existing cells.
Microscope Technology • Microscope technology paved the way to the development of the cell theory and the discovery of cells. • As we continue to grow in technology, so do the details in the images we see of cells. • As detail increases, so do the magnification and resolution on the microscope.
Microscopes Compound Light Microscope Electron Microscopes Glass lenses Uses visible light to produce a magnified image Uses 2 lenses that can magnify 10x, therefore the total magnification would be 100. Often dyes are used to see an image Light limits the resolution of these images • Transmission Electron • Magnet beams • Can magnify 500,000x • Specimen can be living • Sliced thin • Scanning Electron • Produces a 3D image • Black & White image • Non-living • Stained w/heavy metals
Checkpoint Explain how the development and improvement of microscopes changed the study of living organisms. With more sophisticated tools, scientists have been able to learn much more detail about the cell and its structures. Compare & Contrast a compound light microscope and an electron microscope. Light microscopes use visible light and glass lenses. Electron microscopes use beams of electrons and magnets, and can be used to view whole specimens.
Basic Cell Types • Cells differ based on the function they perform for the organism. • HOWEVER, all cells have at least one physical trait in common: their plasma membrane. • The plasma membrane helps control what enters and leaves the cell. • Cells have a variety of functions based on specific organelles found inside. • Most cells have genetic material that provides instructions for making substances that the cell needs. The genetic material is copied to the daughter cells (offspring of the cell). • There are two different types of cells: • Eukaryotic & Prokaryotic
Differences b/w the 2 types of cells Eukaryotic Prokaryotic Larger Contains membrane bound organelles Contains a nucleus Smaller Does not contain membrane bound organelles No nucleus
Checkpoint Differentiate the plasma membrane and the organelles. The plasma membrane helps control what goes in and out of the cells. Organelles carry out specialized functions in the cell.
Origin of Cell Diversity • According to the endosymbiotic theory: • Prokaryotic cells lived within eukaryotic cells. • Which means cells came from a simple prokaryotic cell composed of few organelle structures may have evolved further from the multi-cellular eukaryotic cell to have its own identity.
At the end of NOTES… Answer questions 1-7 (you DO NOT have to write out the question) on page 211. Make sure you create 4 questions on the left side of your notes. Write a summary for your notes…at least 5 sentences in length.
9/20-9/24 Daily Warm Up What is an example of a prokaryotic cell? Bacteria What are the differences between eukaryotic and prokaryotic cells. Size Nucleus Organelles
9/20-9/24 Daily Warm Up Describe how the plasma membrane helps maintain homeostasis in the cell. By controlling what enters & leaves the cell. Explain how the inside of a cell remains separate from its environment. The phospholipid bi-layer provides a barrier from the environment outside of the cell.
9/20-9/24 Daily Warm Up What do carbohydrates do in reference to the cell membrane? Recognize foreign pathogens & transmits chemical signals. (Without looking at the book or notes) List 5 organelles found in cells. Nucleus Ribosomes E.R. Golgi Apparatus Mitochondria
9/20-9/24 Daily Warm Up Work on your story if you didn’t finish…
Chapter 7 Section 2 The Plasma Membrane Note: The Plasma Membrane is the same as the cell membrane!
Function of the Plasma Membrane • The plasma membrane is responsible for maintaining the organisms internal environment through selective permeability. • This is called homeostasis.
Function of the Plasma Membrane • The plasma membrane’s function is to allow waste and other products to leave the cell and nutrients to enter, & maintains the proper internal environment. • Selective permeability is the property of the plasma membrane that allows some substances to pass through while keeping others out. • Example: Think of a fish net.
Structure of the Plasma Membrane • Most molecules in the plasma membrane are lipids. • Lipids are large molecules composed of glycerol and 3 fatty acids. • A phospholipid forms when a phosphate group replaces a fatty acid. • A phospholipid bilayer contains two layers of phospholipids arranged tail to tail. • The arrangement is present so that the plasma membrane can exist in a watery environment.
The phospholipid bilayer The bilayer structure is critical for the formation and function of the plasma membrane. Polar Head: Phosphate Group Attracted to H2O Hydrophilic P Non-polar Tail: Fatty acid chains Repel H2O Hydrophobic
The phospholipid bilayer The 2 layers make a sandwich with the fatty acid tails forming the interior of the p.m. and the phospholipid heads facing the watery environments found inside and outside the cell. The phospholipids are arranged in such a way that the polar heads can be closest to the water molecules and the nonpolar tails can be farthest away from water molecules. The plasma membrane can separate the environment inside the cell from the environment outside the cell.
Other components of the plasma membrane • Major components: • Cholesterol, proteins and carbohydrates.
Proteins • Found on the outer surface of the p.m. proteins called receptors transmit signals to the inside of the cell. • Proteins on the inner surface anchor the p.m. to the cells internal support structure, giving it shape. • Carrier proteins are located throughout the cell to move substances and/or waste materials.
Cholesterol • Cholesterol helps to prevent the fatty-acid tails of the phospholipid bilayer from sticking together, which allows for fluidity. • Avoiding a high cholesterol diet is recommended because just enough is needed for cellular function. • If you have too much your body’s cells have to compensate.
Carbohydrates • Stick to proteins and help cells identify chemical signals. • Example: carbs might help disease-fighting cells recognize and attack a potential harmful cell.
Fluid Mosaic Model • The phospholipids in the bilayer create a “sea” in which other molecules can float. • Example: like floating apples in a barrel of water.
Clip http://player.discoveryeducation.com/index.cfm?guidAssetId=1424FB3E-0E64-4DDD-BB75-79262A7DC58B&blnFromSearch=1&productcode=US Cell Walls & Cell Membranes http://player.discoveryeducation.com/index.cfm?guidAssetId=21221A8A-DAFF-4F48-B689-8EE84E82B549&blnFromSearch=1&productcode=US Cell Membranes & Cell Walls
Check Point Identify the molecules in the plasma membrane that provide basic membrane structure, cell identity, and membrane fluidity. Basic Membrane Structure: Phospholipids Cell Identity: Proteins & Carbohydrates Membrane Fluidity: Cholesterol A __________ is the basic structure molecule making up the plasma membrane. Phospholipid The ___________ is the component that surrounds all cells. Plasma Membrane
Check Point ___________ is the property that allows only some substances in and out of the cell. Selective Permeability Hypothesize how a cell would be affected if it lost the ability to be selective in its permeability. Couldn’t maintain homeostasis & it would die. What might happen to a cell if it no longer could produce cholesterol? It would become less fluid.
Chapter 7 Section 2 Notes Make sure you have the checkpoint questions in your notes…they could be potential quiz & test questions. Make sure you have 4 ?’s on the left hand side of your Cornell Notes. Write a summary—at least 5 sentences. The more the merrier…you have a lot information in this section of notes. Work on Chapter 7 Section 2 Worksheet Both are DUE TOMORROW!
Section 3 Structure & Organelles
