Prokaryotic and Eukaryotic Cells Flashcards
(27 cards)
What is cell theory?
Cell theory states that the cell is the fundamental unit of life, organisms are made up of one or more cells, and cells arise from preexisting cells.
What does cell theory imply about the nature of life?
Cell theory implies that all organisms are made up of cells, some organisms are unicellular, and multicellular organisms have specialized cells for survival functions.
Why is the cell considered the fundamental unit of life?
The cell is the basic structural and functional unit of life. All life processes occur within cells.
How do cells arise?
Cells arise from preexisting cells through the process of cell division.
What is the relationship between cell structure and function?
The structure of a cell is specifically designed to perform functions essential for the cell’s survival and the organism’s overall survival.
What defines a prokaryotic cell?
A prokaryotic cell is a single-celled organism lacking a nucleus and membrane-bound organelles. It includes bacteria and archaea.
What is the genetic material in prokaryotic cells?
The genetic material in prokaryotic cells is concentrated in a region called the nucleoid.
Do prokaryotic cells have a cell wall?
Yes, prokaryotic cells typically have a cell wall that provides structural support.
What is the size of prokaryotic cells?
Prokaryotic cells are small, typically 1-2 micrometers in diameter, with a high surface area to volume ratio.
What is the significance of the surface area to volume ratio in prokaryotic cells?
The high surface area to volume ratio in prokaryotic cells allows for efficient nutrient absorption and faster metabolic reactions.
When does translation occur in prokaryotic cells?
Translation occurs as soon as mRNA is transcribed from DNA, due to the lack of separation between transcription and translation.
What defines a eukaryotic cell?
A eukaryotic cell can be unicellular or multicellular and contains a nucleus and membrane-bound organelles, including mitochondria, the nucleus, and the endoplasmic reticulum.
What types of organisms are made up of eukaryotic cells?
Animals, plants, fungi, and protists are made up of eukaryotic cells.
How do eukaryotic cells compare in size to prokaryotic cells?
Eukaryotic cells are larger than prokaryotic cells and have a smaller surface to volume ratio.
What is the function of the mitochondria in eukaryotic cells?
The mitochondria are responsible for ATP synthesis via the electron transport chain, providing energy for cellular functions.
What is the role of the nucleus in eukaryotic cells?
The nucleus houses the majority of the cell’s DNA in the form of chromosomes, allowing for complex regulation of gene expression.
What is the relationship between transcription and translation in eukaryotic cells?
In eukaryotic cells, transcription occurs in the nucleus, and translation occurs in the cytoplasm, separated in space and time.
What is the endoplasmic reticulum (ER) and its function?
Rough ER (RER):
Protein Synthesis – Ribosomes on RER make proteins.
Protein Folding – Helps in folding and modifying newly made proteins.
Transport – Sends proteins to the Golgi apparatus via vesicles.
Smooth ER (SER):
Lipid Synthesis – Produces phospholipids and steroids.
Detoxification – Breaks down toxins in liver cells.
Calcium Storage – Regulates calcium ions in muscle cells.
*Carbohydrate Metabolism *– Helps in converting glycogen to glucose.
How does the size of eukaryotic cells affect their surface-to-volume ratio?
Eukaryotic cells are larger, so they have a smaller surface-to-volume ratio, but their internal complexity compensates for this by compartmentalizing chemical reactions.
How did eukaryotes evolve from prokaryotes?
Eukaryotes evolved from a certain type of archaea. The first eukaryotic common ancestor engulfed an alpha-proteobacterium which established a symbiotic relationship. The bacterium provided ATP
What is the significance of the mitochondria’s cristae in eukaryotic evolution?
Mitochondria evolved cristae as part of their adaptation and specialization which is critical for their role in ATP production within eukaryotic cells.
- Increased Surface Area - Cristae greatly increase the inner membrane’s surface area, allowing more space for enzymes and proteins involved in cellular respiration.
- Efficient ATP Production - Supports higher rates of aerobic respiration, enabling efficient ATP generation, which is essential for powering complex eukaryotic cell functions.
- Support for Complex Life - The energy boost from ATP allowed the evolution of larger, more complex, and multicellular organisms.
- Linked to Endosymbiotic Theory - Mitochondria evolved from free-living bacteria. The development of cristae shows how the host cell optimized energy production, aiding in the success of eukaryotes.
What is endosymbiosis?
Endosymbiosis is the theory that mitochondria and chloroplasts originated from prokaryotes that were engulfed by an ancestral eukaryotic cell forming a symbiotic relationship.
What evidence supports the theory of endosymbiosis?
Evidence includes the mitochondria having its own circular DNA similar to prokaryotes
What is primary endosymbiosis?
Primary endosymbiosis is the initial engulfment of a prokaryote (such as a bacterium) by an ancestral eukaryotic cell which led to the formation of organelles like mitochondria and chloroplasts.
