Cell Organelles PDF

3.2 Cell Organelles  Objective: Cell Organelles 1. What organelles are Unit 3- Part 2 found in Eukaryotic Cells and Prokaryotic Cells? 2. What are the functions of each of...

3.2 Cell Organelles  Objective: Cell Organelles 1. What organelles are Unit 3- Part 2 found in Eukaryotic Cells and Prokaryotic Cells? 2. What are the functions of each of these organelles?  Eukaryotic Cells Nucleus This is the control center of the cell- brain of the cell Contains cell’s DNA  Eukaryotic Cells Nucleolus Nucleolus Inside the nucleus Creates ribosomes Eukaryotic Cells Cell Membrane —> Cell membrane Phospholipid bilayer structure Selectively permeable ○ Allows some things to pass through while keeping other things out. Fluid mosaic model ○ The cell membrane is made of many different components, and they can move around one another.  Eukaryotic Cells Ribosomes Smallest of all organelles, no membrane Makes protein for growth Also found in eukaryotic & prokaryotic cells Eukaryotic Cells Endoplasmic Reticulum (ER) A system of folded membranes that act as an internal transportation system Substances use the ER to move about the cell The “highways” and “roads” of a cell Eukaryotic Cells Rough ER - Folded Membrane with many ribosomes attached. - Important for protein synthesis. Eukaryotic Cells Smooth ER - Essential in lipid synthesis - Folded membrane - “Smooth” because it does not have ribosomes attached to the membrane. Eukaryotic Cells Mitochondria Place where sugar is broken down to produce energy (ATP) ○ Adenosine triphosphate: Cells use this energy to do work The “powerplant” of the cell Has its own DNA Eukaryotic Cells Lysosome This organelle contain digestive enzymes that help to keep a cell clean Digests food particles, gets rid of waste, and protects from foreign invaders Known as the cell's “defense” system Eukaryotic Cells Golgi Packages up materials in a cell and gets ready to be transported out of the cell or to other parts of the cell Eukaryotic Cells Cytoskeleton Supports and gives shape to the cell Help transport materials around the cell Made up of protein chains called microfilaments and microtubules ○ Is the grey lines in the diagram —> Eukaryotic Cell's- Just for animal cells Vesicle Place that holds water in an animal cell Instead of one big place to hold water, there are several in an animal cell Vesicle Eukaryotic Cell's- Just for animal cells Centrioles - Aid in cell division. - Help provide internal structure for the cell. Label as much as you can! Eukaryotic Cell's- Just for plants/prokaryotic Cell wall Only found in plants, fungi and prokaryotic cells Rigid structure that helps to support the plant or fungi Eukaryotic Cell's- Just for plants Chloroplast Only found in plants and algae Place where plants make their own food during photosynthesis Gives plants their green color Contain their own DNA Eukaryotic Cell's- Just for plants Vacuole Place where water is stored in a plant cell One large vacuole per plant cell The “holding tank” of plant cell's When cell's have empty vacuoles, a plant will wilt Name the few differences that a plant cell has that an animal cell does not: Plant cells Endosymbiotic Theory Mitochondria and the chloroplast are both organelles that were once free-living cells They were prokaryotic cells that were ingested by other prokaryotes EVIDENCE supporting Endosymbiotic Theory Mitochondria and chloroplasts have their own DNA Their DNA is similar to DNA in prokaryotes They divide independently of the cell They have multiple membranes  Located in…. Please Complete Exit Ticket in Schoology! Cell Membranes  BR- Cell Size/Specialization (1) 1. Compared to a skin cell, a muscle cell is likely to have more _____. a. golgi bodies b. chloroplasts c. cell membranes d. mitochondria  BR- Cell Size/Specialization (2) 2. A cell with numerous ribosomes is probably specialized for _____. a. cell division b. energy production c. protein synthesis d. enzyme storage Cell Membranes - Fluid Mosaic Model Mosaic: There are many components of the cell membrane. Fluid: The components of the cell membrane can move around.  Functions of Membranes 1. Protects the cell 2. Control incoming and outgoing substances 3. Selectively permeable - allows some molecules in, others are kept out  Parts of the Cell Membrane 1. Phospholipid Bilayer - allows for fluidity - Hydrophilic heads (likes water) - Hydrophobic tails (does not like water) More unsaturated tails = more fluid More saturated tails = more rigid.  Parts of the Cell Membrane Proteins- helps with transport into and out of the cell (integral and peripheral proteins) 2. Transport Proteins: Transport material across the cell membrane. 3. Enzymes: Mediate chemical reactions. 4. Recognition Proteins: Glycoproteins for identification.  Parts of the Cell Membrane Recognition Proteins (Glycoproteins)- helps with cell to cell recognition (like a fingerprint for the cell)  Parts of the Cell Membrane 5. Cholesterol- helps stabilize lipid bilayer. Acts as a fluidity-rigidity buffer for the cell membrane Keeps membrane more fluid at cold temperatures. Keeps membrane more rigid at hot temperatures.  Parts of the Cell Membrane 6. Cytoskeleton- inside the cell, connects to cell membrane to give the cell structure, shape, movement within the cell, and movement of the cell - Microtubules (large) https://youtu.be/y-uuk4Pr2i8 - Intermediate filaments (medium) - Microfilaments (small)  Game Time!!! Cell Explorer: The Animal Cell https://biomanbio.com/HTML5Ga mesandLabs/Cellgames/cellexplor erpagehtml5.html Read the directions Level 4🡪 is the most important try to get a 100% here (you can try as many times as you’d like) SHOW ME when you get your score! Phospholipid Bilayer  Cell Membrane Outside of cell Carbohydrate chains Proteins Cell membrane Inside of cell (cytoplasm) Protein channel Lipid bilayer Fluid Mosaic Model Movement Across Cell Membranes Diffusion , Osmosis, and Active Transport Cell Membrane Function The cell membrane helps to maintain homeostasis by regulating what goes into and out of the cell, keeping concentrations of various substances at optimal levels. A solution is….. a solute (generally a solid) dissolved in a solvent (generally a liquid). In biology, we mostly deal with aqueous (or water-based) solutions) Terminology Isotonic: Concentration of solute outside of the cell is the same as concentration inside the cell. Hypertonic: When the solution outside the cell has a higher concentration than inside the cell. Hypotonic: When the solution outside the cell has a lower concentration than inside the cell.  Isotonic Solution Isotonic: The concentration of solutes in the solution is equal to the concentration of solutes inside the cell. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions Result: Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium)  Hypotonic Solution Hypotonic: The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute; High water) Result: Water moves from the solution to inside the cell: Cell Swells and bursts open (cytolysis)!  Hypertonic Solution Hypertonic: The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute; Low water) shrinks Result: Water moves from inside the cell into the solution: Cell shrinks (Plasmolysis)!  Cell Membrane Transport There are four methods by which substances can move across the cell membrane (into or out of the cell) to maintain optimal concentrations: 1. diffusion 2. osmosis 3. facilitated diffusion 4. active transport Diffusion Particles in a solution are moving constantly. They collide with each other and tend to spread out randomly. Diffusion is the movement of particles from an area of high concentration to an area of low concentration. We call this movement from high to low concentration “going down the gradient.” High –> Low  Osmosis Cell membranes are considered to be selectively permeable, which means only certain molecules can move through the membrane. Many molecules are too large to move through the membrane so water moves to even out the concentrations. Osmosis is the diffusion of water through a selectively-permeable membrane. Osmosis The sugar molecules cannot pass through the membrane, but the water molecules can. Therefore the water molecules will pass through the membrane until the concentrations of sugar are equal on both sides  Passive Diffusion Molecules move down the concentration gradient until all particles reach equilibrium (particles are equally distributed), without the use of energy. At equilibrium particles continue to move across the membrane in equal numbers in both directions.  Direction of osmosis of water depends on the concentration of the surrounding solution Water will move in a direction to try to get the concentrations equal inside and outside the cell!  Facilitated Diffusion Facilitated diffusion is the movement of specific molecules across the cell membrane through protein channels (the protein channels “facilitate” or assist the molecule’s movement across the membrane). Molecules move from areas of high concentration to areas of low concentration and does not require energy. Example: Red blood cells have glucose channels that specifically transport large molecules of glucose from one side of the cell to the other Facilitated Diffusion Substances enter or leave the cell by passing through a protein channel in the cell membrane Concentration gradients (the difference in concentration of molecules across a space) Diffusion happens passively as molecules move from an area of high concentration to low concentration. We say they are “moving down a gradient”. Active transport involves the movement of molecules “against the gradient” (from low concentration to high) and requires energy to overcome the concentration differences.  Active Transport Sometimes molecules must move against the concentration gradient (from low concentration to a high concentration). This is called active transport and requires the use of energy. Active Transport - Endocytosis Endocytosis is an example of active transport. It is the process of taking material into the cell by folding in or creating pockets of the cell membrane. There are two types of endocytosis: 1. phagocytosis (“Cell eating”) 2. pinocytosis (“cell drinking” )  Active Transport - Endocytosis 1. Phagocytosis means “cell eating”. Extensions of the cytoplasm surround a particle and package it within a food vacuole. Active Transport - Endocytosis 2. Pinocytosis is when tiny pockets form along the cell membrane, fills with liquids, and pinch off to form vacuoles within the cells. Active Transport - Exocytosis Exocytosis is an example of active transport that is the process of releasing large amounts of material from the cell. Comparison of Passive vs Active Transport Active transport requires energy!