cells. the microscope the light microscope the light microscope – invented by anton van...

CELLSCELLS

The 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• Took about 200 years of work to

develop• Three basic principles of cell

theory…

The Cell Theory1. 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 Scalehttp://learn.genetics.utah.edu/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, CytoplasmIncludes fungi, Includes animals, Includes bacteria, Includes plants

Mitochondria, Cell membrane, Small and simple, More complex

Prokaryotes EukaryotesBoth

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 AnimalsBoth

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.

Organelle Function In A Factory…

Nucleus - Controls all the activities of the cell (like gene expression)

- Where DNA is located

Organelles – Nucleus

Main Office

Organelle Function In A Factory…

DNA - DNA/Chromosomes provide directions for the assembly line workers (the ribosomes

Organelles – DNA

Blueprints

Organelle Function In A Factory…

Ribosomes - Ribosomes use instructions from DNA to make cellular products --- PROTEINS!

Organelles – Ribosomes

Assembly Line Workers

Organelle Function In A Factory…

Mitochondria-Converts food energy (glucose) into cell energy- The cell “powerhouse”- Contains its own DNA

Organelles – Mitochondria

Generator

Organelle Function In A Factory…

Golgi Apparatus

- Packages proteins from the endoplasmic reticulum and sends them to other parts of the cell

Organelles – Golgi Apparatus

Mailroom

Organelle Function In 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

Organelle Function In A Factory…

Vacuole - Stores cellular materials (like nutrients nd waste products)

- Provides structure and support to plant cells

Organelles – Vacuole

Storage Warehouse

Organelle Function In A Factory…

Centrioles***found only in animal cells

-Tiny tubes that help organize cell division- Helps make new cells!

Organelles – Centrioles

Human resources

Organelle Function In 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

Organelle Function In A Factory…

Cell Membrane

(plasma membrane)

- Regulates what entersand leaves the cell- Keeps unwanted things (like bacteria) out and lets wanted things (like nutrients) in

Organelles – Cell Membrane

Main Door

Organelle Function In 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

Organelle Function In 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

Organelle Function In A Factory…

Lysosome- Contains enzymes

that break down (digest) lipids and proteins

- Removes “junk” from the cell

Organelles – Lysosome

Trash Compactor

Organelle Function In A Factory…

Nuclear Membrane

(nuclear envelope)

- Two-membrane envelope- Dotted with nuclear pores that allow materials to move in and out of the nucleus

Nucleolus Small, dense region of the nucleus that produces ribosomes

Organelles – Nuclear Membrane and Nucleolus

Door to main officeQuality Control

Organelle Function In 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

Organelle Function In A Factory…

Cytoplasm - Gel-like part of the cell located outside of the nucleus

Organelles – Cytoplasm

Factory Floor