2.1.1: Ultrastructure Of Cells Flashcards
What is the definition of fluidity in cell membranes?
Fluidity refers to the flexibility and movement of molecules within the membrane structure.
Fluidity is crucial for the proper functioning of cell membranes, allowing for the movement of proteins and lipids.
What role does cholesterol play in the plasma membrane?
Cholesterol provides strength and reduces fluidity of the membrane.
Cholesterol is essential for maintaining the integrity and stability of the membrane.
What are glycoproteins?
Glycoproteins are proteins with a carbohydrate attached.
They play key roles in cell recognition and signaling.
What are glycolipids?
Glycolipids are lipids with a carbohydrate attached.
They are important for cell recognition and communication.
What type of cells are eukaryotic cells?
Eukaryotic cells contain a range of organelles.
This includes structures such as the nucleus, mitochondria, and endoplasmic reticulum.
List three organelles found in animal cells.
- Mitochondrion
- Ribosome
- Rough endoplasmic reticulum
List three organelles found in plant cells.
- Lysosome
- Smooth endoplasmic reticulum
- Chloroplast
Describe the structure of the plasma membrane.
The plasma membrane consists of a phospholipid bilayer with embedded proteins and cholesterol.
The arrangement allows for both structural integrity and fluidity.
What does the fluid-mosaic model refer to?
The fluid-mosaic model refers to the fluidity and range of molecules in the membrane.
It illustrates how various components can move laterally within the membrane.
What is the function of channel proteins?
Channel proteins facilitate the transport of molecules across the plasma membrane.
They provide passageways for specific ions and molecules.
What is the role of peripheral membrane proteins?
Peripheral membrane proteins are attached to the exterior or interior surfaces of the membrane.
They often play roles in signaling or maintaining the cell’s shape.
Fill in the blank: Glycoproteins and glycolipids act as _______ and receptors.
[cell recognition]
True or False: The nuclear envelope surrounds the nucleus and contains nuclear pores.
True
What is the function of ribosomes in eukaryotic cells?
Ribosomes are responsible for protein synthesis.
They can be found free in the cytoplasm or bound to the rough endoplasmic reticulum.
What is chromatin?
Chromatin is the complex of DNA and proteins found in the nucleus.
It condenses to form chromosomes during cell division.
What is the function of the Golgi body?
The Golgi body modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.
It is essential in processing and shipping cellular products.
What is the function of the nucleolus?
The nucleolus is responsible for ribosomal RNA (rRNA) synthesis and ribosome assembly.
It is located within the nucleus.
What is the role of the cytoplasm?
The cytoplasm is the gel-like substance within the cell that contains organelles and facilitates metabolic processes.
It supports and suspends the organelles.
Fill in the blank: The _______ is a double membrane that encloses the nucleus.
[nuclear envelope]
What is the significance of nuclear pores?
Nuclear pores regulate the exchange of substances between the nucleus and cytoplasm.
They allow for the selective transport of molecules.
What is the difference between integral and peripheral membrane proteins?
Integral membrane proteins span the membrane, while peripheral membrane proteins are attached to the membrane’s exterior or interior surfaces.
Integral proteins often function as channels or transporters.
List two types of proteins found in the plasma membrane.
- Integral membrane proteins
- Peripheral membrane proteins
What is the function of the centriole?
Centriole is involved in cell division and the organization of microtubules.
It plays a crucial role in forming the spindle fibers.
