Prokaryotic and Eukaryotic Cells

 Smallest living unit
 Most are microscopic

• Cells Have Large Surface
Area-to-Volume Ratio

 Cells have a high surface to volume ratio to allow materials (food, O2, water) to come in and waste (CO2, etc.) to move out at an efficient rate
 If cells were any bigger waste products would not move out as quickly as other materials move in and the cell would quickly die

1.
2.
3.
4.
A surrounding membrane called the cell membrane
Protoplasm or cytoplasm – cell contents in thick fluid
Control center with DNA
All cells have ribosomes which make protein

 Prokaryotic
 Eukaryotic

These are two distinct types of cells with
STRUCTURAL differences.
Eukaryotes
Prokaryotes
Eubacteria
Archaea
Bacteria
Animal
Protists Plant
Fungi

Prokaryotic Cell Structures and Functions

 Are single celled organisms
 Include Eubacteria and Archaebacteria cells

 No membrane bound nucleus
 DNA (genetic material) is in the
Nucleoid region

No “real” or membrane bound organelles

 Prokaryotes have the following Structures:
 Cell wallmade of peptidoglycans; for protection and support for the shape
 DNAis circular; used for reproduction, repair, and maintenance
 Flagellum (or flagella pl.)- for movement
 Ribosomesto make proteins
 Cytoplasmsuspend/hold internal structures in place
 Pilito stick to surface and exchanging DNA

 Coccus or Cocci
(pl.) – circular or sphere like
 Spirillum – spiral shaped
 Bacillus – rod shaped

 DiseaseSome bacteria will directly attack the tissues of plants and animals that could potentially be fatal Ex: Bubonic Plague caused by Yersinia pestis
 ToxinsSome bacteria will attack organisms by releasing chemicals that are poisonous to plants and animals. Ex:
Clostridium tetani causes tetanus or lockjaw, a disease in which the toxin paralyzes any muscle tissue

 Digest food – Many types of bacteria live in the digestive systems of animals to help break down cellulose and make essential vitamins
 Decomposersbacteria break down waste materials into simple substances that can be used by plants
 Production of human foodbacteria help create a variety of dairy products, vinegar, sauerkraut, and beverages

 Complete the Prokaryotic Cell
Worksheet

Animal and Plant Structures and Functions

 Characteristics or Features:
 Nucleus bound by membrane
 Include fungi, protists, plant, and animal cells
 Will have many organelles
Protozoan

 Exterior Structures
 Cell membrane
 Cell Wall
 Flagella
 Cilia
 Interior structures include:
 Cytoplasm
 Cytoskeleton

 Functions:
 Contains cell contents
 Regulates what materials are allowed in and what materials move out
 Fluid mosaic model – describes fluid nature of a lipid bilayer with proteins

 Found in plants , fungi, & many protists
 Surrounds plasma membrane
 It protects the cell and gives it shape
 Cell Wall Differences:


Plants – mostly cellulose
Fungi – contain chitin

 Provide ability to move
 Cilia
 Short, hair-like structures
 Used to move substances outside human cells
 Flagella


Long tail-like extensions locomotion

 Filaments & fibers
 Made of 3 fiber types


Microfilaments
Microtubules
 Intermediate filaments



3 functions: mechanical support anchor organelles
 help move substances

 Viscous fluid containing organelles




Components of cytoplasm
Interconnected filaments & fibers
Fluid = cytosol
Organelles (not nucleus)

 Cellular machinery
 Organelles are “little organs” inside the cell that have a special function or job
 Different Organelles inside the cell are:
 Golgi Bodies
 Lysosomes
 Mitochondria
 Rough and Smooth ER
 Chloroplasts
 Vacuoles
 Centrioles and Centrosomes

 Pairs of microtubular structures
 Play a role in cell division

 Control center of cell
 Contains the DNA
 Double membrane
 Contains:
 Chromosomes/ chromatin
 Nucleolus
 Nucleoplasm

 Hereditary material
 Chromosomes
 DNA
 Proteins
 Form for cell division
 Chromatin – loosely spread out DNA

 Most cells have 2 or more
 Directs synthesis of RNA
 Forms ribosomes

 Helps move substances within cells
 Network of interconnected membranes
 Two types
 Rough endoplasmic reticulum (Rough ER)
 Smooth endoplasmic reticulum (Smooth ER)

 Ribosomes attached to surface
 Manufacture proteins
 Not all ribosomes attached to rough ER
 May modify/change proteins from ribosomes

 Ribosomes are made of ribosomal RNA or rRNA
 They may be found on Rough ER or floating freely in the cytoplasm
 They help synthesize proteins

 No attached ribosomes
 Functions:
 Has enzymes that help build molecules
○ Carbohydrates
○ Lipids
 Also helps detoxify foreign substances
 Stores calcium

 Involved in synthesis of plant cell wall
 Packaging & shipping station of cell

1. Molecules come in vesicles
2. Vesicles fuse with Golgi membrane
3. Molecules may be modified by Golgi
4. Molecules pinched-off in separate vesicle
5. Vesicle leaves Golgi apparatus
6. Vesicles may combine with plasma membrane to secrete contents

 Contain digestive enzymes
 Functions
 Aid in cell renewal
 Break down old cell parts
 Digests invaders

 Membrane bound storage sacs
 In plants it is called the central vacuole ; it contains:
 Water
 Food
 Wastes
 In protists, they are called contractile vacuoles

 Have their own DNA
 Bound by double membrane
 Break down fuel molecules ( cellular respiration)
 Glucose
 Fatty acids
 Release energy
 ATP (energy molecule
Of cell)

 Found in plant cells and some unicellular organisms
 Contains a green pigment called chlorophyll
 Organelle that uses sunlight to create carbohydrates (photosynthesis)