Membrane Structure Flashcards
(30 cards)
What is the primary function of the plasma membrane?
To act as a barrier that regulates the entry and exit of substances in and out of the cell.
True or False: The plasma membrane is permeable to all substances.
False
What are the main components of the plasma membrane?
Phospholipids, proteins, cholesterol, and carbohydrates.
Fill in the blank: The plasma membrane is composed of a __________ bilayer.
phospholipid
What role do cholesterol molecules play in the plasma membrane?
They help to maintain fluidity and stability of the membrane.
Which type of proteins are embedded within the lipid bilayer?
Integral proteins
True or False: Glycoproteins are proteins that have carbohydrates attached to them.
True
What is the fluid mosaic model?
A model that describes the structure of the plasma membrane as a mosaic of diverse protein molecules embedded in a fluid phospholipid bilayer.
What is the function of peripheral proteins?
They are attached to the exterior or interior surfaces of the membrane and play roles in signaling and maintaining the cell’s shape.
Multiple Choice: Which of the following is NOT a function of the plasma membrane? A) Transport, B) Protection, C) Energy production, D) Cell communication
C) Energy production
How do ions typically pass through the plasma membrane?
Through ion channels or transport proteins.
What is the significance of membrane fluidity?
It allows for the movement of proteins and lipids within the membrane, facilitating cell signaling and transport.
Fill in the blank: The hydrophilic heads of phospholipids face __________ the aqueous environment.
toward
What is passive transport?
The movement of substances across the plasma membrane without the use of energy.
True or False: Active transport requires energy to move substances against their concentration gradient.
True
What is endocytosis?
A process by which cells internalize substances by engulfing them in a vesicle.
Multiple Choice: Which type of endocytosis involves the uptake of liquid? A) Phagocytosis, B) Pinocytosis, C) Receptor-mediated endocytosis, D) Exocytosis
B) Pinocytosis
What role do membrane carbohydrates play?
They are involved in cell recognition and signaling.
Fill in the blank: The plasma membrane is selectively __________.
permeable
What is exocytosis?
The process by which cells expel materials in vesicles that fuse with the plasma membrane.
True or False: The composition of the plasma membrane is the same in all cell types.
False
What is the primary structure that defines the boundaries of a cell?
The plasma membrane
What are transmembrane proteins?
Proteins that span the entire lipid bilayer and can function as channels or receptors.
Multiple Choice: Which of the following is a characteristic of the plasma membrane? A) Rigid structure, B) Fluid-like nature, C) Completely impermeable, D) Static composition
B) Fluid-like nature
