Unit 2: Cellular Biology PPT 2: LESSONS 2.4, 2.5, 2.6, 2.7, 2.8, 2.9

Unit 2 Cellular Biology Part 2 Table Of Contents 2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

Definition of a Cell A cell is the smallest unit that is capable of performing life functions.

Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell

Discovery of Cells Robert Hooke (mid-1600s) Observed sliver of cork with a microscope Saw “row of empty boxes” Coined the term cell

Cell theory (1839)Theodor Schwann & Matthias Schleiden “ all living things are made of cells” 1889 (50 yrs. later) Rudolf Virchow “all cells come from other cells”

Cell Theory All living things are made up of cells. Cells are the smallest working units of all living things. All cells come from preexisting cells through cell division.

Cell Size

Unit 2 Cellular Biology Part 2 Table Of Contents 2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

Age of the Earth The universe as a whole is estimated to be about 13.8 billion years old. Our solar system (and our planet, Earth) is estimated to have begun approximately 4.568 billion years ago. The Milky Way Galaxy, our home turf.

Glow in the dark squid… how does it do that?

Vibrio fischeri Glow in the dark bacteria Helps the squid survive in the deep ocean Lives in fish and other marine life

Two Types of Cells Prokaryotes (prokaryotic cells) Eukaryotes (eukaryotic cells)

Prokaryotes Oldest of cell types, first appeared on Earth 3.8 billion years ago. Domain Bacteria, Domain Archaebacteria Very simple and small cells. Do not have membrane-bound organelles,

Prokaryotes Do not have a real nucleus Nucleoid: region of concentrated DNA (some have it, some don’t) Can live in hostile environments. ALL are Unicellular organisms, such as Bacteria Escherichia coli

Prokaryotic Cells

Naming Shapes of Prokaryotes Cocci = spherical (round) Bacillus = rod shaped Spirilla = helical (spiral)

Eukaryotes First appeared on Earth approximately 1.5 billion years ago. Complex internal structure, larger than prokaryotes Have a nucleus, with DNA (genetic material) inside. Contain organelles surrounded by coverings called membranes Plant Animal

Eukaryotes Can be both unicellular or multi-cellular Most living organisms, including all known members of Kingdoms Protista, Fungi, Plantae, Animalia.

Video – Amoeba Sisters

How do the differences line up? Prokaryotes Organelles lack a membrane Ribosomes are the only organelles Genetic material floats in the cytoplasm (DNA and RNA) Eukaryotes Organelles covered by a membrane Multiple organelles including ribosomes Membrane covered Genetic material

How do the differences line up? Prokaryotes Circular DNA Unicellular Cells are smaller in size Has larger number of organisms Eukaryotes Linear DNA May be multicellular or unicellular Cells are larger in size Has smaller number of organisms

“Typical” Animal Cell Structure

“Typical” Plant Cell Structure

Unit 2 Cellular Biology Part 2 Table Of Contents 2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

Surrounding the Cell Cell Membrane (ALL cells) Cell Wall (Plants & Fungi, some bacteria, NOT animal cells)

Cell Membrane Found in ALL cell types Function: Surrounds the cell Forms the barrier between the cell and its outer environment. Selectively Permeable: Controls what enters or leaves the cell

Cell Membrane Structure: Double layer of molecules called “phospholipids”. Therefore, called a phospholipid bilayer

HYDROPHOBIC = WATER FEARING HYDROPHILIC = WATER LOVING Cell Membrane Phospholipids: 2 parts: Head – hydrophilic Tail – hydrophobic HYDROPHOBIC = WATER FEARING HYDROPHILIC = WATER LOVING

Cell Membrane Structure: Embedded (stuck in) the phospholipid bilayer are several other molecules: Cholesterol: provides structure for the membrane Proteins: transport things in to or out of the cell communicate with the outside environment

Cell Membrane Fluid Mosaic Model of the Membrane: Many molecules embedded in the membrane make it look like a mosaic (yes, like art) The molecules are not fixed in place, they are fluid - they move side-to-side frequently.

Fluid Mosaic Model

Cell Wall Most commonly found in PLANT, BACTERIA & FUNGI cells Surrounds the cell membrane (on the outside) Supports and protects the cell

Cytoplasm Found in ALL cell types Function: Suspends (holds) the internal cells structures and organelles Structure: A thick, gel-like material that fills the inside of the cell Made of nutrients, enzymes, and water.

Nucleus Found ONLY in Eukaryotic cells Separated from the cytoplasm by the nuclear membrane Function: Controls the cell’s activities (BRAIN of the Cell) Contains genetic material (DNA)

Nuclear Envelope Function: Surrounds the nucleus Structure: Has 2 layers: Inner membrane Outer membrane Openings (called pores) allow material to enter and leave nucleus

Nuclear Membrane/Envelope

Chromosomes Inside nucleus Made of DNA Function: DNA is genetic material: instructions for construction, control, traits & characteristics of the cell/organism

Nucleolus Structure: dark spot inside nucleus Function: Creates RNA, which is used to build proteins

Nucleus

Cytoskeleton Prokaryotes & eukaryotes Structure: Network of protein strands, like a skeleton Function: Supports and maintains shape of cell Involved in cell movement and internal transport

Unit 2 Cellular Biology Part 2 Table Of Contents 2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

Endoplasmic Reticulum (ER) Function: Moves materials around in cell Structure: folded phospholipid bilayer (membrane material) 2 Types: Rough (pictured): has ribosomes embedded in surface (black dots) Smooth: no ribosomes. Endoplasmic reticulum

Endoplasmic Reticulum Around the Nucleus

Smooth ER vs. Rough ER More Functions: Rough ER - ribosomes on the ER make proteins, the ER modifies the proteins Smooth ER – no ribosomes. makes lipids

Endoplasmic reticulum

Ribosomes Each cell contains thousands of ribosomes Found on endoplasmic reticulum, on nuclear membrane & floating throughout the cytoplasm of the cell Function: Make proteins to build cell structures

Mitochondria Found in BOTH ANIMAL & PLANT cells Function: Produces energy (ATP) for the cell “Powerhouse of the Cell” Cellular Respiration – a chemical reaction that breaks down fats & carbohydrates into ATP (energy).

Mitochondria Structure: Outer membrane inner folded membrane (cristae) Matrix (cytoplasm) mitochondrial DNA

Golgi Apparatus ‘Packaging & shipping station‘ of the cell Function: Packages materials (proteins) for transport Preparing to move materials out of the cell Structure: Made of a stack of flattened membrane sacs.

Lysosome Structure: Membrane sac containing strong enzymes (chemicals) Produced by the Golgi apparatus Function: Digests proteins, fats, and carbohydrates, and damaged organelles Transports undigested material to cell membrane for removal Cell breaks down if lysosome explodes! (“suicide bags”)

Copyright © The McGraw-Hill Companies, Inc Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Cytoplasm Extracellular fluid Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cytoplasm Endoplasmic reticulum Food vesicle Golgi apparatus Lysosomes Transport vesicle Old or damaged organelle Plasma membrane Digestion of food particles or cells Breakdown of old organelle Extracellular fluid

Vacuoles Found in ANIMAL & PLANT cells Structure: Membrane-bound sacs, contains a water solution Function: For storage, digestion, and waste removal Help plants maintain shape (central vacuole)

Central Vacuole in Plants

Chloroplast Found ONLY in PLANT cells Contains green chlorophyll Function: Site of photosynthesis Photosynthesis: chemical reaction that uses light energy and carbon dioxide to make oxygen and sugar Have their own DNA

Centrioles Found ONLY in ANIMAL cells Structure: Cylindrical structures found near the nucleus Made of hollow, tubular structures arranged in bundles Function: Used in cell division

Cell City Song

Organelles Rap

Unit 2 Cellular Biology Part 2 Table Of Contents 2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

Mitochondria vs. Chloroplasts Mitochondria make energy (ATP) from food molecules through cellular respiration Chloroplasts make food molecules from light energy through photosynthesis

Plant vs. Animal Cells

Plant Cell

Plant vs. Animal Cells

Animal Cells vs. Plant Cells

Endoplasmic reticulum Plant vs. Animal Cells PLANT CELL ANIMAL CELL Cell membrane Mitochondria Golgi apparatus Nucleus Cytoskeleton Ribosomes Endoplasmic reticulum Lysosomes HAVE: Cell Wall LARGE vacuoles Chloroplasts DO NOT HAVE: Centrioles HAVE: Centrioles DO NOT HAVE: Cell Wall LARGE vacuoles Chloroplasts

Prokaryotes vs. Eukaryotes

Unit 2 Cellular Biology Part 2 Table Of Contents 2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

Flagella Usually found on aquatic cells (living in water) Both prokaryotic and eukaryotic organisms Structure: long, whip like structures Function: help the cell move (like a tail) The only flagellated cell in the human body: the sperm cell

Cilia Cilia are found on eukaryotic cells. Structure: Tiny hair-like structure present on the surface of cell. Can number in the hundreds of thousands per cell. Function: Used for movement (like oars on a boat), or absorption of nutrients False-colored cilia in a lung

Flagella & Cilia

Pseudopodia literally means “false feet”. Structure: projections of the cell’s cytoplasm & membrane Function: movement Also used to engulf (swallow) molecules too large to pass through the cell membrane Amoeba and macrophages (white blood cells) move using pseudopodia

Microvilli They are found on the surface of the cells that line the small intestine of animals. Structure: tiny finger-like projections on the surface of certain types of cells. Function: absorption of materials because they increase the surface area of the cell membrane. Intestinal microvilli, TEM

Cellular Movement Flagella Cillia Pseudopod

Cell Differentiation Cell specialization occurs during the development of a multi-cellular organism. The genetic information necessary for all cellular functions remains in each cell but may not be used.

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