CELLS Structure and Function Cell smallest unit of

CELLS Structure and Function Cell = smallest unit of life

Two Major Cell Types Cell Type Prokaryotic Eukaryotic Example Bacteria Protists Fungi Plants Animals

Prokaryotic Cell

Eukaryotic Cell (protist, animal)

Eukaryotic Cell (plant)

Differences Between Cell Types Prokaryotic Cell Eukaryotic Cell Single circular chromosome Multiple linear chromosomes Chromosome found in a cytoplasmic region called the nucleoid. Chromosomes found in a membranebound nucleus. No internal membranes Some infolded plasma membrane Extensive network of internal membranes

Common Components and Cellular Organization • Plasma Membrane – boundary surrounding the cell • Genetic material: DNA – located in a membrane-bound nucleus for eukaryotic cells • Cytoplasm – Semi-fluid matrix containing enzymes and organelles (enzyme = biological catalyst) • Cytoskeleton – network of filaments and tubules in cytoplasm that maintains cell shape, allows movement

Features of Prokaryotic Cells All prokaryotic cells contain Structure Plasma Membrane Nucleoid Cytoplasm Function Regulates flow of substances into and out of cell Cytoplasmic region containing genetic material Cytosol: fluid Ribosomes Enzymes

Features of Prokaryotic Cells Other possible prokaryotic structures Structure Cell Wall Capsule Infolded Plasma Membranes Function Supports cell Maintains shape Protects from drying Protects against white blood cells Metabolism Cell division

Features of Prokaryotic Cells Other possible prokaryotic structures Structure Bacterial Flagellum Plasmid Function Movement Small circular DNA Replicates independently

Applying Your Knowledge 1. 2. 3. 4. 5. Cell Wall Flagellum Capsule Plasmid Nucleoid In bacterial cells • where is the genetic material located? • which one is used for movement? • which one provides structural support for the cell?

Functions of Eukaryotic Cell Features Structure Function(s) 1. Regulates passage of Plasma materials into and out of cell Membrane 2. Cell-Cell Recognition

Functions of Eukaryotic Cell Features Structure Cell Wall (protists, fungi, plants) Function(s) 1. Controls cell shape, protects, supports

Functions of Eukaryotic Cell Features Structure Nucleus Function(s) 1. Carrier of genetic material DNA + protein = chromatin 2. Governs cell activities 3. Directs cell reproduction 4. Surrounded by Membrane = nuclear envelope 5. Contains nucleolus— produces ribosomes which synthesize proteins

Functions of Eukaryotic Cell Features Structure SER RER Function(s) Rough 1. Associated ribosomes produce Endoplasmic proteins Reticulum (RER) 2. Prepares proteins for export Smooth 1. Lipid Synthesis Endoplasmic 2. Drug detoxification Reticulum (SER) 3. Transport of proteins from RER

Functions of Eukaryotic Cell Features Structure Function(s) Golgi Apparatus Collects, modifies, packages and distributes proteins and lipids from ER

Functions of Eukaryotic Cell Features Structure Lysosome Function(s) Contains digestive enzymes to digest food in protists or destroy aging organelles

Endomembrane System Rough Endoplasmic Reticulum Smooth Endoplasmic Reticulum Vesicle Golgi Apparatus Vesicle Lysosome Vesicle Plasma Membrane

Functions of Eukaryotic Cell Features Structure Peroxisome Function Removes harmful oxidants from cells

Functions of Eukaryotic Cell Features Structure Mitochondrion Function Captures energy from organic molecules, producing ATP

Functions of Eukaryotic Cell Features Structure Function Chloroplast Photosynthesis: Uses light (protists, plants) energy to produce organic molecules

Functions of Eukaryotic Cell Features Structure Cytoskeleton Function(s) 1. 2. 3. Maintains cell shape Anchors organelles and proteins Allows for organelle movement and cellular movement in some cell types

Functions of Eukaryotic Cell Features Structure Function Centriole Gives rise to basal bodies that produce cilia or flagella

Functions of Eukaryotic Cell Features Structure Function(s) Vacuole 1. Central vacuole (plants) stores waste, maintains turgidity. 2. Contractile vacuole (protists) maintains water balance. 3. Food vacuole (protists) fuses with lysosome for digestion.

Functions of Eukaryotic Cell Features Structure Cilia and Flagella Function(s) 1. Move substances across cell surface in lungs, fallopian tubes 2. Cell movement in sperm, protists

Applying Your Knowledge 1. 2. 3. 4. 5. Cilium Rough ER Golgi apparatus Smooth ER Lysosome A. Which organelle produces proteins that will be exported from the cell? B. Which organelle contains digestive enzymes? C. Which site acts as a protein packaging and distribution center?

Thought Questions 1. What are similarities for a. eukaryotic and prokaryotic cells? b. animal and plant cells? 2. What are differences between a. eukaryotic and prokaryotic cells? b. animal and plant cells?

Analogy If the cell were a factory the __________ would be (name a cell component) a _______________. (name a part of a factory)

Part of Cell Part of Factory Capsule Security Gate Cell Wall Outer Fence around the factory Chloroplast Solar Panel Cytoskeleton Moving Belt where items are inspected Steel Support, Interior Walls Cilia/Flagella Conveyor Belt, Elevator/Escalator Enzyme Worker; Assemblage Machinery Golgi Complex Distribution/Packaging Department Mailroom Mitochondrion Generator, Engine Room, Power Source Nucleoid Storage of pre-production material Nucleus Supervisor’s Office, Boss Corporate Office, Central Operations Plasma Membrane Loading/Unloading Dock, Inner Wall, Door Ribosomes Assembly Line Track RER Production Line SER Shipping Dock

Cellular Interactions Ø Signal Transduction: passing a signal from the cell surface to the interior Ø First messenger binds to Cell Surface Receptor Ø Receptor signals nearby Regulator Protein Ø Regulator activates nearby enzyme Ø Enzyme catalyzes formation of Second Messenger Ø Second Messenger initiates Cellular Response

Cellular Interactions Ø Cell Adhesion: joining of cells controlled by proteins called Cellular Adhesion Molecules (CAMS) important in Ø Ø Ø Inflammatory Response Placenta Formation Learning and Memory Lack of cell adhesion is implicated in cancer and arthritis.