Cell Biology: Prokaryotes and Eukaryotes

What is a key characteristic that distinguishes eukaryotic cells from prokaryotic cells?

Which of the following organisms is classified as a prokaryote?

Which structure is NOT found in prokaryotic cells?

Which of the following options correctly describes eukaryotic cells?

Which of the following groups includes organisms made up of eukaryotic cells?

What is a primary focus of microbial biotechnology in the food industry?

Which of the following best describes the role of microbial processes in food production?

How does microbial biotechnology contribute to sustainable food practices?

What is a significant biotechnological advancement in the food industry?

What is an ethical concern associated with biotechnological applications in the food industry?

Acidity (pH) is considered an intrinsic factor affecting microbial activity in food.

The storage conditions of food are classified as intrinsic factors that influence microbial activity.

Both intrinsic and extrinsic factors play a role in microbial activity within food.

Temperature is an intrinsic factor that influences microbial growth.

Intrinsic factors are determined by the composition of the food itself.

The mitochondria is often referred to as the 'powerhouse' of the cell because it is involved in respiration.

The nucleus is the cell structure that contains the cell's ribosomes.

The 'daughter' cell splits off from the 'mother' cell during the process of cell division.

The nuclear membrane encloses the mitochondria in a cell.

Cells with a nuclear membrane are classified as prokaryotic.

Prokaryotic and Eukaryotic Cells

Prokaryotic cells lack a nucleus and membrane-bound organelles.
Eukaryotic cells have a nucleus and membrane-bound organelles.
Two main types of cells are prokaryotes and eukaryotes.

Prokaryotes

Bacteria are prokaryotes.

Eukaryotes

Plants, fungi, animals, and humans are eukaryotes.

Cytoplasm

The cytoplasm of a bacterial cell is the site of growth, metabolism, and replication.

Ribosomes

Ribosomes are tiny factories that translate genetic code from nucleic acids to amino acids, which are the building blocks of proteins.

Pruteen

Pruteen is made from the bacterium Methilophilus methilotrophus.

Spirulina

Spirulina is a cyanobacteria from the genus Arthrospira.
Spirulina is available as whole cells and beta carotenes.

Daughter Cell

A new cell that forms from an original cell, referred to as the "mother" cell.

Mitochondria

Known as the "powerhouse" of the cell.
The site where respiration occurs.

Nucleus

Contains DNA, the genetic material of the cell.

Nuclear Membrane

The membrane that surrounds the nucleus.

Factors Governing Microbial Activity In Food

Intrinsic Factors: Attributes of the food itself.
- Acidity (pH): Impacts the growth and survival of microorganisms.
Extrinsic Factors: External conditions influencing microbial activity.
- Storage conditions: Temperature, humidity, and atmosphere can significantly affect microbial growth.

Naming and Classifying Microorganisms

The Linnaean system of binomial nomenclature is used for naming organisms.
Each organism has two names:
- Genus: First name, capitalized.
- Species: Second name, lowercase.

Scientific Names

Should be italicized or underlined.

Yogurt

A fermented dairy product made by inoculating milk with bacterial culture.
The bacteria convert lactose into lactic acid.
The acid causes casein protein to denature, forming a semi-solid gel.
Lactococcus thermophilus and Streptococcus bulgaricus are the key bacteria involved in yogurt production.
S. thermophilus lowers the pH of milk to 5.5.
L. bulgaricus converts lactose to lactic acid.
The taste of yogurt is influenced by organoleptic aspects and the number of bacteria present.