Bacteria

Question 1

Briefly discuss the structure of bacteria

Answer 1

Bacteria lack nuclei and membrane bound organelles. They form rods, spirals and spheres. There are gram positive bacteria and gram negative bacteria

Question 2

Discuss gram positive bacteria vs gram negative bacteria

Answer 2

The murein layer in gram negative bacteria is thinner than that of gram positive bacteria. Gram negative bacteria has an outer membrane resistant to harm as well as a periplasmic space

Question 3

LPS in gram negative bacteria is made of 3 parts, what are they?

Answer 3

1. Lipid A aka endotoxin causing fever and shock
2. Core polysaccharide
3. O antigen which varies between bacteria, they are toxic

Question 4

How do hydrophilic molecules pass?

Answer 4

The outer membrane has pores which permit diffusion of many hydrophilic compounds. Large hydrophilic compiles are moved by specific transport complexes, the periplasm contains digestive enzymes binding proteins for transport and enzymes that inactivate antibiotics. The inner cell membrane also has specific transport mechanisms

Question 5

Many bacteria are surrounded by a capsule of polysaccharide or polymer of amino acids. What is its function?

Answer 5

It is a determinant of ability to colonize a niche and protect from desiccation. It is also a major defense against phagocytosis by phagocytic cells

Question 6

What is the term used for bacterial reproduction?

Answer 6

Binary fission

Question 7

How do bacteria readily exchange DNA?

Answer 7

1. Transformation
2. Conjugation via pili
3. Transduction

Question 8

Name a few uses of harnessing bacteria

Answer 8

1. Food production- cheese, yogurt, vinegar
2. Medicinal drugs- antibiotics, probiotics
3. Waste treatment- sewage disposal, bioremediation