L3: Archaea

Question 1

Define archaea

Answer 1

Single, nucleusless cells that don’t fit the criteria to be bacteria or eukaryotes.

Question 2

Identify the properties of archaea

Answer 2

1. Oldest form of life.
2. Their cells lack peptidoglycan.
3. Extremophiles - deep sea vents, acidic/alkaline environment, hot springs.
   4.Methanogenic - produce methane as a metabolic byproduct.
4. Reproduce asexually.
5. Genetic diversity.

Question 3

How archaea differ to bacteria

Answer 3

1. Different RNA polymerases
2. Different RNA ribosomal proteins.
3. Archaea more specialised for extreme conditions.
4. Most archaea have S-layer made of protein molecules.

Question 4

How archaea differ archaea to eukaryotes

Answer 4

1. Simpler cell structure.
2. Smaller in size.
3. Single circular chromosome.
4. Archaea reproduce asexually.
5. Archaea dont have introns
6. Archaea have isoprenoids.

Question 5

Life at extremes: Name the 5 extremes (conditions)

Answer 5

Heat (thermophile)
Cold (psychrophile)
pH (Acidophile)
Pressure (Barophile)
Salts (halophile)

Question 6

How are the cell walls of bacteria and archaea different?

Answer 6

Bacteria contain peptidoglycan, archaea have pseudopeptidoglycan.

Question 7

What is methanogenesis in archaea?

Answer 7

Archaea makes methane as a byproduct of it’s metabolic pathway.

Question 8

Archaea makes methane as a byproduct of it’s metabolic pathway What is this process callled?

Answer 8

Methanogenesis.

Question 9

How is the cell membrane composition in archaea different to bacteria?

Answer 9

Archaea have isoprenoids. Bacteria have lipids ie fatty acids.

Question 10

Bacteria or archaea? A fatty acid, linked by ester bond to glycerol-3-phosphate?

Answer 10

Bacteria

Question 11

Bacteria or archaea? A fatty acid, linked by ester bond to glycerol-2-phosphate?

Answer 11

Neither. Archaea has Isoprenoid, and glycerol-1-phosphate. Bacteria has fatty acid and glycerol-3-phosphate.

Question 12

Bacteria or archaea? Isoprenoid, linked by ester bond to glycerol-1-phosphate?

Answer 12

Archaea

Question 13

Bacteria or archaea? Isoprenoid, linked by ester bond to glycerol-4-phosphate?

Answer 13

Neither. Archaea has Isoprenoid, and glycerol-1-phosphate. Bacteria has fatty acid and glycerol-3-phosphate.

Question 14

What is an isoprenoid?

Answer 14

A compound with 5 carbons and with 2 or more hydro-carbons arranged in a specific pattern.

Question 14

In thermal adaption of archaea, ____________ stabilse DNA using positive s__________

Answer 14

Thermophiles
supercoils