Cell Basics

All cells are either prokaryotic or eukaryotic Two Basic Cell Types All cells are either prokaryotic or eukaryotic

Eukaryotic cells Complex cells that contain a nucleus and many membrane-bound organelles with specialized functions. Animal or plant cells. (also includes fungi and protists)

Nucleus Controls activities of the cell and holds the genetic information (DNA) Surrounded by the nuclear membrane/envelope Ribosomes, which will later be used in protein synthesis, are partially assembled in an area called the nucleolus

The nucleus is known as the “control center” of the cell and is found in all eukaryotic cells. For example, plant and animal cells.

Lets quickly examine the structure and function of the cell membrane: Which of the following animals do you think can pass easily through this opening? Why?

Cell Membrane Regulates what goes in and out of the cell (selective). Composed of lipids and proteins.

Cytoplasm Cytoplasm is a clear, jelly-like fluid that fills the cell

Ribosomes Make proteins. Found throughout the cell and on rough ER.

Endoplasmic Reticulum (ER) System of internal membranes that transport proteins and other substances through the cell. 2 Kinds: Rough ER: transports proteins that are made by ribosomes attached to it Smooth ER: helps make new lipids and helps to break down toxic substances such as alcohol Has no ribosomes attached to it

Which picture best depicts the function of the ER? Highway The ER is referred to as the highway of the cell since it transports molecules, such as proteins, throughout the cell. Capital Apple tree Shopping mall

Golgi Apparatus Flattened, membrane-bound sacs that serve as the packaging and distribution center of the cell. They modify the proteins that travel from the ER in vesicles (small, membrane-bound sacs) before they are released to serve their function.

Which picture best depicts the function of the golgi apparatus? The Golgi is sometimes referred to as the post office since it modifies and packages proteins before they are shipped to their rightful destination escalator post office sanitation truck power lines

Mitochondria Releases energy from organic compounds to make ATP (energy) “Powerhouse” of the cell Fact: Mitochondria contain their own DNA and ribosomes to make their own proteins. Who do you inherit your mitochondrial DNA from? Your mother –it’s found within the egg and the father only donates his DNA (23 chromosomes)

Mitochondria Eukaryotic DNA Prokaryotic DNA Mitochondrial DNA a b Look at the mitochondrial DNA and determine whether it looks like picture a or b. Eukaryotic DNA Prokaryotic DNA Mitochondrial DNA a b

Mitochondrial DNA similar to Prokaryotic (bacterial) DNA? This fact supports the widely accepted theory that mitochondria were once primitive prokaryotes! Mitochondrial DNA Prokaryotic DNA

Which picture best depicts the function of the Mitochondria? TXU supplies electricity to many houses and businesses in Dallas just as the mitochondria supplies energy for it’s cell vacuum TXU electric company grocery store water park

Based on your knowledge of mitochondria, which of the following cells would contain a greater number of mitochondria? muscle cell hair cell egg cell stomach cell skin cell Muscle cells require large amounts of energy in order to perform functions and therefore require a larger number of mitochondria

Lysosomes Specialized vesicles that contain digestive enzymes Function by digesting and recycling the cell’s used components (carbs, proteins, lipids and old organelles)

Which picture best depicts the function of the lysosome? Stomach Both contain digestive enzymes and both help to breakdown particles Trash can Chimney

Cytoskeleton A network of protein structures that determines cell shape Provides support for organelles and pathways for cell movement.

Some structures are found in plant cells but not animal cells…

Cell wall Helps support, protect and maintain the shape of the cell

Chloroplasts Elodea cells Chloroplast Use light energy to make carbohydrates from carbon dioxide and water (photosynthesis). Elodea Elodea cells Chloroplast

circular like prokaryotes and mitochondria Just like mitochondria, chloroplasts contain their own DNA and are also thought to be descendents of ancient prokaryotic cells circular like prokaryotes and mitochondria soy bean chloroplast

“Large” Central Vacuole Stores water and may contain many substances, including ions, nutrients, and wastes Largest organelle found in plants When full of water, the cell becomes rigid (turgor pressure) FYI: Small vacuoles are found in animal cells.

Cell Organelles Animal Plant Cell Membrane Mitochondria Chloroplast Endoplasmic Reticulum Nucleus Vacuole Lysosome Golgi Body Ribosome Cell Wall Animal Plant

Prokaryotes, which includes all bacteria Prokaryotes, which includes all bacteria. They are the simplest cellular organisms. They have genetic material but no nucleus. Typical bacteria cell

Bacteria! Prokaryotic cells Unicellular No membrane bound organelles – therefore, not many specialized functions. Bacteria!

Flagella Tail-like structure that helps bacteria move (MOTILITY) Flagella are also found on some eukaryotic cells. For example, some protists have flagella. So do sperm cells!

Pili Hair-like structure that helps bacteria stick to surfaces

Capsule A sticky outer protective covering that allows bacteria to adhere to surfaces Increases their ability to cause disease

Name the structures of this bacterium. 1. 5. 2. 6. 3. 7. 4. Ribosomes Flagella Pili Cell wall DNA(circular chromosome) Capsule Cell membrane

Different Types of Cells Prokaryotic Eukaryotic no nucleus no nucleus nucleus nucleus small ribosomes larger ribosomes small ribosomes larger ribosomes no organelles no organelles organelles organelles very small 1-10µm very small small small 2-1000µm only in bacteria protists, fungi, plants, animals protists, fungi, plants, animals only in bacteria