CELLS

The Microscope The light microscope The light microscope – Invented by Anton van Leeuwenhock in 1600’s – Improvements brought about the compound light microscope – Enabled scientists to view and study cells

The Cell Theory Started with the work of Robert Hooke Started with the work of Robert Hooke Took about 200 years of work to develop Took about 200 years of work to develop Three basic principles of cell theory… Three basic principles of cell theory…

The Cell Theory 1.All organisms are composed of one or more cells. 2.The cell is the basic unit of structure and function in living things. 3.All cells come from preexisting cells.

Remember the 8 Characteristics of Living Things: ***living things are made up of units called cells

Cells are Really Small! Cell Size and Scale du/content/cells/scale/ du/content/cells/scale/

What’s a cell? A cell is the basic element of life and the simplest unit of structure and function in living things.

Levels of Organization

Unicellular Organisms Unicellular organisms have one single cell. How many wheels does a unicycle have? One. UNI- cellular means ONE cell!

Multicellular Organisms Multicellular organisms are made up of many cells.

Multicellular Organisms Multicellular organisms depend on cell communication because they have different cells that perform different functions.

Multicellular Organisms Because of cell specialization and differentiation, cells within an organism can develop to perform different tasks.

Think About It. What cells in humans help us…..move? Muscle Cells!

Think About It. What cells in humans help us…..feel? Nerve Cells!

Think About It. What cells in humans help us.....carry blood? Red Blood Cells!

Think About It. What cells in humans help us.....think? Brain Cells! (Nerve Cells)

Think About It. These cells have different structures and different functions, but they are all cells. We need all of our cells to communicate and work together in order to survive.

Basic Cell Types: Prokaryotes vs. Eukaryotes Prokaryotes are very small cells without membrane-bound organelles. These cells hold little more than ribosomes and loose DNA that is not contained in a nucleus. Examples: bacteria

Basic Cell Types: Prokaryotes vs. Eukaryotes Eukaryotes are organisms with many membrane-bound organelles. They can be single-celled or multi-celled, and they have DNA contained in a separate area of the cell called the nucleus. Examples: fungi, protists, plants, animals

Prokaryotes vs. Eukaryotes Humans are animals – YOU are a “you”karyote!

Ribosomes, DNA, DNA in a nucleus, DNA loose in cell, Cytoplasm Includes fungi, Includes animals, Includes bacteria, Includes plants Mitochondria, Cell membrane, Small and simple, More complex Prokaryotes Eukaryotes Both

Basic Cell Types: Plant Cells vs. Animal Cells Plant and animal cells contain most of the same organelles, but there are a few differences: – Plant cells have a cell wall, which is made of cellulose (starch)

Basic Cell Types: Plant Cells vs. Animal Cells Plant and animal cells contain most of the same organelles, but there are a few differences: – Plant cells have chloroplasts, which are used during photosynthesis

Basic Cell Types: Plant Cells vs. Animal Cells Plant and animal cells contain most of the same organelles, but there are a few differences: – Plant cells (usually) have one larger vacuole

Basic Cell Types: Plant Cells vs. Animal Cells Plant and animal cells contain most of the same organelles, but there are a few differences: – Animal cells have centrioles, which are used during cell division

Cell Wall, Centrioles, Chloroplasts, Endoplasmic reticulum, Golgi apparatus, Cytoplasm, Lysosomes, Mitochondria, Nucleus, Cell Membrane, Ribosomes, Vacuole (large), Vacuole (small), Cytoskeleton Plants Animals Both

Eukaryotic Cell Structure A eukaryotic cell is like a busy factory. It has lots of little “machines” that work together and interact. Some give instructions, some produce energy, some create products, and others provide storage or get rid of waste. These little machines are called organelles.

Eukaryotic Cell Structure Organelles are literally “little organs”. They are smaller structures within a cell that act like specialized organs.

Eukaryotic Cell Structure Organelles are literally “little organs”. They are smaller structures within a cell that act like specialized organs.

OrganelleFunctionIn A Factory… Nucleus-Controls all the activities of the cell (like gene expression) -Where DNA is located Organelles – Nucleus Main Office

OrganelleFunctionIn A Factory… DNA-DNA/Chromosomes provide directions for the assembly line workers (the ribosomes Organelles – DNA Blueprints

OrganelleFunctionIn A Factory… Ribosomes-Ribosomes use instructions from DNA to make cellular products --- PROTEINS! Organelles – Ribosomes Assembly Line Workers

OrganelleFunctionIn A Factory… Mitochondria -Converts food energy (glucose) into cell energy - The cell “powerhouse” - Contains its own DNA Organelles – Mitochondria Generato r

OrganelleFunctionIn A Factory… Golgi Apparatus - Packages proteins from the endoplasmic reticulum and sends them to other parts of the cell Organelles – Golgi Apparatus Mailroom

OrganelleFunctionIn A Factory… Endoplasmic Reticulum -Ribosomes are attached to Rough ER -Transports materials -Prepares proteins for export Organelles – Rough Endoplasmic Reticulum Assembly Line or Conveyor Belt

OrganelleFunctionIn A Factory… Vacuole-Stores cellular materials (like nutrients nd waste products) -Provides structure and support to plant cells Organelles – Vacuole Storage Warehouse

OrganelleFunctionIn A Factory… Centrioles ***found only in animal cells -Tiny tubes that help organize cell division - Helps make new cells! Organelles – Centrioles Human resources

OrganelleFunctionIn A Factory… Cytoskeleton - Network of proteins - Like scaffolding and walls – provides support, shape, and structure inside of our cells - Also involved in movement - Cilia and flagella Organelles – Cytoskeleton Walls, scaffolding within factory

OrganelleFunctionIn A Factory… Cell Membrane (plasma membrane) - Regulates what enters and leaves the cell - Keeps unwanted things (like bacteria) out and lets wanted things (like nutrients) in Organelles – Cell Membrane Main Door

OrganelleFunctionIn A Factory… Chloroplast ***found only in plant cells -Where photosynthesis occurs - Chloroplasts convert energy from the sun into food energy (sugars) - Enclosed by two membranes - Contains green pigment called chlorophyll Organelles – Chloroplasts Solar Panels

OrganelleFunctionIn A Factory… Cell Wall ***found only in plant cells -Provides structure and protection for the cell - Outside of the cell membrane - Made of cellulose Organelles –Cell Wall Security Fence

OrganelleFunctionIn A Factory… Lysosome -Contains enzymes that break down (digest) lipids and proteins -Removes “junk” from the cell Organelles – Lysosome Trash Compactor

OrganelleFunctionIn A Factory… Nuclear Membrane (nuclear envelope) - Two-membrane envelope - Dotted with nuclear pores that allow materials to move in and out of the nucleus NucleolusSmall, dense region of the nucleus that produces ribosomes Organelles – Nuclear Membrane and Nucleolus Door to main office Quality Control

OrganelleFunctionIn A Factory… Smooth Endoplasmic Reticulum -Similar structure to rough ER, but no ribosomes are attached (feels ‘smooth’) -Helps make lipids for the cell Organelles –Smooth Endoplasmic Reticulum Conveyor Belt/ Assembly Line

OrganelleFunctionIn A Factory… Cytoplasm- Gel-like part of the cell located outside of the nucleus Organelles – Cytoplasm Factory Floor