Microbial Growth

Question 1

Define nutrients

Answer 1

Supply of monomers (or precursors of) required by cells for growth

Question 2

Describe carbon and what kind of nutrient it is

Answer 2

It is Required by all cells and is a Major element in all classes of macromolecules. Heterotrophs use organic carbon and Autotrophs use carbon dioxide (CO2)

Question 3

Describe nitrogen

Answer 3

Key element in proteins, nucleic acids, and many more cell constituents

Question 4

What are the 8 Macronutrients?

Answer 4

Carbon, nitrogen, phosphorus, sulfur, potassium, magnesium, calcium, sodium

Question 5

Describe phosphorus

Answer 5

Synthesis of nucleic acids and phospholipids

Question 6

Describe potassium

Answer 6

Required by enzymes for activity

Question 7

Describe magnesium

Answer 7

Stabilizes ribosomes, membranes, and nucleic acids and Also required for many enzymes

Question 8

Describe calcium

Answer 8

Helps stabilize cell walls in microbes
Plays key role in heat stability of endospores

Question 9

Describe sodium

Answer 9

Is Required by some microbes (e.g., marine microbes)

Question 10

What are growth factors and examples of it? Describe the main micronutrient

Answer 10

Organic compounds required in small amounts by certain organisms, Examples: vitamins, amino acids, purines, pyrimidines
Iron is a Key component of cytochromes and FeS proteins involved in electron transport

Question 11

What is culture media and its 2 broad classes?

Answer 11

Nutrient solutions used to grow microbes in the laboratory
Defined media: precise chemical composition is known
Complex media (more common): composed of digests of chemically undefined substances (e.g., yeast and meat extracts)

Question 12

How can media be broken down?

Answer 12

Into a liquid, Semisolid or solid media containing agar or gelatin

Question 13

What are the 3 main types of media and examples of them?

Answer 13

Enriched media- contains complex media plus additional nutrients
Differential media – allows multiple types of bacteria to grow but displays visible differences in how they grow, ex.Spirit Blue Agar, Starch Agar, Skim Milk Agar
● Selective media- inhibits the growth of bacteria, ex.Asparagine Agar , Phenyl Ethyl Alcohol Agar

Question 14

Describe sulfur

Answer 14

Creates Sulfur-containing amino acids (cysteine and methionine) or Vitamins (e.g., thiamine, biotin, lipoic acid) and coenzyme A