Lecture 1 (Erhardt)

Question 1

What are the main energy sources of bacteria?

Answer 1

Protonmotor Force and ATP

Question 2

Phylogenetic Tree

Answer 2

Prokaryotes: Bacteria & Archaea
Eukaryotes: Funghi, Protozoa, Algae

Question 3

What does the Eocyte hypothesis say?

Answer 3

Eocyte Hypothesis:
- Eukaryotes evolved from Crenarchaeota (eocytes) instead of being a separate, independent domain.
- Supports a two-domain model (Archaea + Bacteria).
- Based on ribosomal RNA and protein similarities.
- Backed by genomic evidence, including Asgard archaea (e.g., Lokiarchaeota).

Question 4

What are advantages for a bacteria to be small?

Answer 4

Advantages to being small
- Surface to volume ratio: Small cells tend to grow faster and support greater nutrient exchange per unit cell volume

Question 5

Bacteria - Different Types of Morphology

Answer 5

Different Types of Morphology
- Spirochetes form a spiral shape
- Budding & appendaged bacteria are Bacteria that undergo a life cycle
- Filamentous bacteria have Multicellularity and produce biofilms

Question 6

Escherichia coli - a bacterial model organism

Answer 6

Escherichia coli
Domain: Bacteria
Phylum: Proteobacteria
Class: γ-Proteobacteria
Family: Enterobacteriacaea
Genus: Escherichia
Species: E. coli
Strain (Isolates from nature or lab): K12
Genome size: 4.6 million base pairs, encoding 4,300 proteins. Each gene responsible for a single protein is about 1,500 nucleotides (nt) long

Question 7

What is the “Central Dogma of Molecular Biology”?

Answer 7

Central Dogma of Molecular Biology
- Theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein.
- Transfer of information from nucleic acid to nucleic acid, or from nucleic acid to protein may be possible, but transfer from protein to protein, or from protein to nucleic acid is impossible