L1 - 2: Cells and Endosymbiosis

What does cell theory state?

1. All organisms are made up of cells.

2. The cell is the fundamental unit of life.

3. Cells come from pre-existing cells.

What four characteristics define cells as the smallest units of life?

1. Genetic information: ability to pass and interpret.

2. Ability to harness and transform energy: Metabolism; Make ATP or synthesize sugars

3. Have a membrane

4. Ability to acquire nutrients: build macromolecules and use as nutrients (minor)

What are the three domains of life?

1. Bacteria

2. Archaea

3. Eukarya

Of the three domains of life, which are prokaryotic?

Bacteria and Archaea?

Differences between prokaryotes and eukaryotes?

• Prokaryotes are smaller.

• Prokaryotes have no membrane-bound organelles.

• Prokaryotic genetic information is located in the nucleoid (circular chromosome) as well as in small plasmids. NO NUCLEUS

What’s a multicellular organism?

An organism made up of more than one cell.

Can bacteria be multicellular?

They can form multicellular filaments or aggregates.

What’s a unicellular organism?

An organism made up of one cell.

Can eukaryotic organisms be unicellular?

Yes (ex: fungi)

What’s endosymbiosis?

Endosymbiosis is a relationship where one organism lives inside another

What two organelles are thought to have originated from bacteria?

Chloroplasts and mitochondria

What are the five signs that the two specific organelles in eukaryotic cells potentially came from bacteria?

1. Double membranes

2. DNA in the form of a circular chromosome

3. Similar DNA sequences

4. Also undergoes binary fission, independent of eukaryotic cells.

5. Has own ribosomes; synthesizes own proteins.

Where are chloroplasts thought to have originated from

From an ancestor consuming a cyanobacteria.

Do plants have mitochondria?

They have mitochondria and chloroplasts unique-ish to plant cells

Life originated from what?

Prokaryotes

Can prokaryotic cells be multicellular?

Typically unicellular but have multicellular forms.

Cytosol vs cytoplasm.

Cytoplasm includes the organelles; cytosol is the aqueous component of the cytoplasm.

Cell wall (E vs P)

Y - Prokaryotic, Y/N for Eukaryotic (plants, fungi, algae)

Do prokaryotic or eukaryotic cells have cell membranes?

They BOTH have.

Main location of genetic material in eukaryotic and prokaryotic cells?

Nucleoid - Prokaryotic, Nucleus - Eukaryotic

Other locations of genetic material in eukaryotic and prokaryotic cells?

Plasmids - Prokaryotic, Mitochondrion and Chloroplasts - Eukaryotic

Circular DNA in eukaryotic and prokaryotic cells?

Yes - Prokaryotic, mostly No - Eukaryotic (exception: mitochondrion and chloroplasts)

Linear DNA in eukaryotic and prokaryotic cells?

Mostly no - Prokaryotic, Yes - Eukaroytic

Ribosomes in eukaryotic and prokaryotic cells?

Yes for BOTH.

Do all eukaryotes have chloroplasts?

No. Plant and algae cells have chloroplasts.

What cells don’t have a mitochondria?

Prokaryotic cells and mature red blood cells.