PROKARYOTIC EUKARYOTIC CELLS As you have already learned

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PROKARYOTIC & EUKARYOTIC CELLS

PROKARYOTIC & EUKARYOTIC CELLS

 As you have already learned, everything is made up of living cells. And

As you have already learned, everything is made up of living cells. And the cells themselves are made up of many different parts. There are many different cells that do many different things, but all of these cells fall into one of the two main categories: Prokaryotic cells & Eukaryotic cells

WHAT THE WORDS MEAN Prokaryotes Eukaryotes Pro = before Eu = true Karyose =

WHAT THE WORDS MEAN Prokaryotes Eukaryotes Pro = before Eu = true Karyose = kernel, which represents the nucleus Karyose = kernel, the nucleus So prokaryotes occurred before cells with a nucleus So eukaryotes are the cells with a true nucleus Ex. Bacteria Ex. Found in animals, plants, and fungi (yeast)

WHAT THEY HAVE IN COMMON DNA Cell (plasma) membrane Ribosomes Simple in Prokaryotic, complex

WHAT THEY HAVE IN COMMON DNA Cell (plasma) membrane Ribosomes Simple in Prokaryotic, complex in Eukaryotic Cytoplasm Allow the flow of nutrients and wastes to enter and leave the cell Have similar metabolic ( life processes) like photosynthesis and respiration Require a supply of energy Made from the same basic chemicals Carbohydrates, proteins, nucleic acid, fats, minerals, and vitamins

DIFFERENCES That’s what they have in common, but there are significant differences too. The

DIFFERENCES That’s what they have in common, but there are significant differences too. The two main ones are age and structure.

AGE DIFFERENCES Scientists believe that prokaryotic cells (in the form of bacteria) were the

AGE DIFFERENCES Scientists believe that prokaryotic cells (in the form of bacteria) were the first life forms on earth. They are considered “primative” and originated 3. 5 billion years ago. That is 2 billion years before eukaryotic cells and billions of years before our earliest ancestor, the hominids. 4. 6 billion years ago – Earth was formed 3. 5 billion years ago – the first life arose: prokaryotic bacteria 1. 5 billion years ago – eukaryotic cells arose 500 million years ago – multi-celled eukaryotes arose 3 million years ago – our earliest ancestor, the hominids, appeared

STRUCTURAL DIFFERENCES Eukaryotic cells contain two important things that prokaryotic cells do not: A

STRUCTURAL DIFFERENCES Eukaryotic cells contain two important things that prokaryotic cells do not: A nucleus Membrane bound organelles

DNA Although both contain DNA: The DNA in eukaryotic cells in in the membrane

DNA Although both contain DNA: The DNA in eukaryotic cells in in the membrane bound nucleus The DNA in prokaryotic cells floats around in the cell in what we call a Nucleoid – not a real structure, just a word to describe the inside of the cell where the nuclear material sits

ORGANELLES The organelles in eukaryotic cells allow them to perform more complex functions than

ORGANELLES The organelles in eukaryotic cells allow them to perform more complex functions than prokaryotic cells. Prokaryotic cells do not have organelles like eukaryotic cells. Both have ribosomes, but they are much more complex in Eukaryotic cells.

CHLOROPLASTS AND MITOCHONDRIA Evidence suggests that chloroplasts and mitochondria were once bacteria that developed

CHLOROPLASTS AND MITOCHONDRIA Evidence suggests that chloroplasts and mitochondria were once bacteria that developed a symbiotic relationship with cells that have a nucleus Chloroplasts and mitochondria have their own DNA that is not a part of the cells. Yes, plants have both chloroplasts and mitochondria.

SIZE Eukaryotic cells are about 10 times larger than prokaryotic cells.

SIZE Eukaryotic cells are about 10 times larger than prokaryotic cells.

CELL WALL Both have a cell wall, but they are made up of different

CELL WALL Both have a cell wall, but they are made up of different substances. Well, eukaryotic plant cells do.

FLAGELLA & CILIA Flagella and cilia are the structures that help cells move. Eukaryotic

FLAGELLA & CILIA Flagella and cilia are the structures that help cells move. Eukaryotic flagella are more complex than prokaryotic flagella.

CHECK FOR UNDERSTANDING Eukaryotic and Prokaryotic Cell Structure Prokaryotic Cell Typical Animal Eukaryotic Cell

CHECK FOR UNDERSTANDING Eukaryotic and Prokaryotic Cell Structure Prokaryotic Cell Typical Animal Eukaryotic Cell Membrane Yes Cell Wall Yes No Cilia or Flagella Yes, simple Yes, complex Endoplasmic Reticulum No Yes Golgi Complex No Yes Lysosomes No Yes Mitochondria No Yes Nucleus No Yes Ribosomes Yes, simple Yes, complex

NEW DISCOVERIES Until recently, it was thought that only eukaryotic cells existed in multi-celled

NEW DISCOVERIES Until recently, it was thought that only eukaryotic cells existed in multi-celled groups like in organs and tissue. Recent discoveries suggest that some prokaryotic cells do too. This is just one more example of how new discoveries are always changing what we know – or think we know. But that is what makes science so exciting! http: //www. ted. com/talks/lang/eng/bonnie_bas sler_on_how_bacteria_communicate. html