Chapter 22: Nutrition, Metabolism and Energy in Microorganisms

What are microorganisms?

Microorganisms are tiny organisms that can only be seen under a microscope. Most of them are single-celled prokaryotes or eukaryotes, but a small portion are aggregates of single cells.

What are living organisms made of?

Living organisms are composed of organic and inorganic compounds.

How many types of microbial culture media are there?

There are 3 types of microbial culture media:

• Natural media: Composed of natural substances such as meat extract, milk, fruit juice, etc.

• Synthetic media: Contains substances with known chemical composition and quantities, such as glucose, mineral salts, etc.

• Semi-synthetic media: Consists of both natural and chemical substances, such as meat extract combined with glucose, mineral salts, etc.

What is heterotrophy?

Heterotrophy is a group of organisms that cannot synthesize organic compounds themselves and depend on other organisms for survival. They use readily available organic matter in the environment to provide energy and raw materials for their bodies.

What is autotrophy?

Autotrophy is the process by which organisms can synthesize the organic (or inorganic) compounds necessary for their body.

What is photoautotrophy?

Photoautotrophy is a method of utilizing the photosynthetic ability of microorganisms, using CO2 to synthesize organic compounds with the help of light energy absorbed by chlorophyll.

What is photoheterotrophy?

Photoheterotrophy is a heterotrophic method that obtains carbon from organic compounds. They use light energy to drive the transformation of organic matter.

What is chemoautotrophy?

Chemoautotrophy is a type of autotrophy where organisms obtain energy from the oxidation of inorganic compounds and use CO2 as a carbon source.

What is chemoheterotrophy?

Chemoheterotrophy is a heterotrophic method that consumes organic compounds to obtain energy and carbon.

How many nutritional types are there in microorganisms?

There are 4 nutritional types in microorganisms: photoautotrophy, photoheterotrophy, chemoautotrophy, and chemoheterotrophy.

What is respiration?

Respiration is a form of chemoheterotrophic metabolism of organic compounds, obtaining energy from the oxidation of organic compounds.

What is anaerobic respiration?

Anaerobic respiration is the process of breaking down carbohydrates to obtain energy for the cell, where the final electron acceptor in the electron transport chain is an inorganic molecule (not O2).

What is aerobic respiration?

Aerobic respiration is the oxidation of organic molecules where the final electron acceptor is oxygen (O2).

What is the most important element for microorganisms to synthesize organic matter and energy?

Carbon is the most important element for microorganisms to synthesize organic matter and energy.