Cells, Cells and more Cells Part One Cell Theory and Structure

The Cell All living things are made of CELLS!! Cells are the smallest functional unit of life – meaning they are the smallest thing that can live on its own The are they basic units of life units of life

How was the cell discovered? Mid 1600s – 2 different scientists discovered the cell in 2 different areas of the world: the world: 1. Robert Hooke 1. Robert HookeEnglish With the use of early compound microscopes, he was able to look at cork (plant material) He used the word “cell” because he thought they looked like small rooms

How was the cell discovered? 2. Anton von Leevenhoek Dutch Dutch With use of single-lens microscope, he observed pond water and other living things With use of single-lens microscope, he observed pond water and other living things While doing his research he While doing his research he found what he called “animacules,” which we now call protists

Further Cell Evidence Matthias Schleiden All plants were made of individual cells All plants were made of individual cells Theodore Schwann Animals were also made up of cells Animals were also made up of cells Rudolf Virchow New cells can only come from the division of existing cells New cells can only come from the division of existing cells All of these discoveries led to the development of the CELL THEORY

Cell Theory – Three Concepts 1.All living things are composed of one or more cells 2.Cells are the basic unit of structure and function in living things 3.New cells are produced from existing cells

Cell Classification Two types of cells, based on whether they contain a nucleus Prokaryotes Prokaryotes Cells that do not have nuclei or membrane bound organelles membrane bound organelles Simple, but can still carry out functions of all living things Eukaryotes Eukaryotes Cells that contain nuclei and other membrane bound organelles Genetic material is separated from the rest of the cell

Eukaryotes Have specific parts of them that perform specific jobs; called organelles Organelles literally means “little organs” Organelles literally means “little organs” Kind of like a city or a factory – everything factory – everything has it’s own job that has it’s own job that makes the whole thing makes the whole thing function function

Eukaryotes & Organelles Two major parts: 1. Cytoplasm JOB: hold organelles in place Portion of the cell outside the nucleus Contains all other organelles The “fluid” that is inside the cell

Eukaryotes & Organelles 2. Nucleus JOB: Contains nearly all of the cell’s DNA JOB: Contains nearly all of the cell’s DNA Holds instructions for the cell Holds instructions for the cell Cell’s Brain Cell’s Brain Parts: Parts: Nuclear Envelope JOB: Surrounds the nucleus JOB: Surrounds the nucleusChromatin JOB: DNA that is bound to protein JOB: DNA that is bound to proteinChromosomes JOB: Contain all the genetic material passed on from one generation of cells to the next JOB: Contain all the genetic material passed on from one generation of cells to the nextNucleolus JOB: Small, dense region that is where the assembly of ribosomes begins JOB: Small, dense region that is where the assembly of ribosomes begins

Eukaryotes & Organelles Ribosomes Small particles of RNA and protein Small particles of RNA and protein Found throughout the cytoplasm Found throughout the cytoplasm JOB: Make proteins JOB: Make proteins

Eukaryotes & Organelles Endoplasmic Reticulum (ER) Internal membrane system Internal membrane system Rough ER Rough ER Has ribosomes attached to it JOB: Assemble and fold proteins Smooth ER Smooth ER JOB: Pathway through the cytoplasm cytoplasm cell membrane to nuclear cell membrane to nuclear membrane membrane JOB: Produces lipids for the cell

Eukaryotes & Organelles Golgi Apparatus Stacklike membranes Stacklike membranes JOB: modifies, sorts and packages proteins JOB: modifies, sorts and packages proteinsPROTEINS: Ribosomes – ER – Golgi Apparatus Ribosomes – ER – Golgi Apparatus

Eukaryotes & Organelles Lysosomes Small organelles filled with enzymes Small organelles filled with enzymes JOB: Digestion/Breakdown of lipids, carbohydrates and proteins into smaller particles that can be used by the rest of the cell JOB: Digestion/Breakdown of lipids, carbohydrates and proteins into smaller particles that can be used by the rest of the cell JOB: Breaking down other organelles that have outlived their usefulness JOB: Breaking down other organelles that have outlived their usefulness

Eukaryotes & Organelles Vacuole: Sack-like structure Sack-like structure JOB: Store materials such as water, salts, proteins and carboyhdrates JOB: Store materials such as water, salts, proteins and carboyhdrates

Eukaryotes & Organelles Mitochondria Powerhouse of the cell Powerhouse of the cell Site of respiration Site of respiration Have their own DNA and manufacture some of their own proteins Have their own DNA and manufacture some of their own proteins JOB: convert chemical JOB: convert chemical energy stored in food into useful compounds “Feeds” the cell “Feeds” the cell Inherited from mother Inherited from motheronly Surrounded by two Surrounded by twomembranes

Eukaryotes & Organelles Chloroplasts JOB: capture energy from sun and convert it into chemical energy (photosynthesis) JOB: capture energy from sun and convert it into chemical energy (photosynthesis) Solar power plant Solar power plant Contains chlorophyll – green pigment that captures sun and makes plants green Contains chlorophyll – green pigment that captures sun and makes plants green Surrounded by two membranes Surrounded by two membranes Have some of their own DNA Have some of their own DNA

Mitochondria and Chloroplasts Have their own genetic material Double membranes Led to the idea that they were once independent organisms that were at one point digested by a larger organism to create a symbiotic relationship

Eukaryotes & Organelles Cytoskeleton JOB: support structure JOB: support structure and help with transportation Protein filaments Protein filaments that help the cell to maintain its shape Also involved Also involved in movement (cytoplasmicstreaming)

Eukaryotes & Organelles Cell Boundaries: Cell Membrane Cell Membrane JOB: regulates what enters and leaves the cell while providing protection and support Lipid bilayer – fluid mosaic model Cell Wall Cell Wall JOB: support and protection

Eukaryotes 2 Types: Animal Animal Smaller Vacuole Plant Plant Larger (Central) Vacuole Chloroplasts Cell Wall