common structures in cells Flashcards
What is the function of the plasma membrane? (5)
- Encloses the contents of the cell.
- Controls the entry and exit of substances.
- Can pump substances into the cell even if the external concentration is low.
- Protects against unwanted or toxic substances.
- Helps maintain concentrations of substances different from the surroundings.
What is the importance of the lipid-based structure of the plasma membrane?
The lipid-based structure of the plasma membrane determines its permeability, allowing the cell to selectively allow or block the entry of substances.
What can cause the lysis of a cell?
- Pressure.
- Viral infections.
- Autolysis (self-destruction).
- All of which can lead to cell death.
What is the role of cytoplasm in a cell?
The cytoplasm:
- Is primarily made of water, with many substances dissolved or suspended in it.
- Contains enzymes that catalyze thousands of chemical reactions, forming the cell’s metabolism.
- Provides the energy needed for the cell and produces the proteins and substances that make up its structure.
- Continuously breaks down and replaces damaged proteins, even when the cell is not growing.
What is metabolism in a cell?
Metabolism refers to all the chemical reactions that occur within a cell, which provide the cell with energy and produce essential molecules like proteins.
What is the function of DNA in a cell?
DNA contains genes that hold the instructions for:
- Protein synthesis (including structural proteins and enzymes).
- Cell functions like growth, repair, and metabolism.
- Heritable genetic material, which is copied and passed to daughter cells during cell division.
Where is DNA located in plant and animal cells versus bacterial cells?
- In plant and animal cells, DNA is stored in the nucleus.
- In bacterial cells, DNA is found in the cytoplasm since bacteria lack a nucleus.
What is the significance of DNA being the universal genetic material?
The use of DNA as genetic material is universal, meaning it is common to all cells, regardless of organism type. This highlights its fundamental role in encoding genetic information across all life forms.
