1 choice answer Flashcards
What are the two main components of the lipid bilayer?
Phospholipids and cholesterol
True or False: The lipid bilayer is a selectively permeable barrier.
True
Fill in the blank: The lipid bilayer is composed of a double layer of ________ molecules.
Phospholipid
What is the definition of selective permeability?
Selective permeability is the property of a membrane that allows certain substances to pass through while preventing others from passing.
True or False: Selective permeability is essential for maintaining homeostasis in cells.
True
What are some factors that affect the selectivity of a membrane?
Size, charge, and solubility of molecules
Fill in the blank: Selective permeability is achieved through the presence of ________ in the membrane.
protein channels or transporters
What is a concentration gradient?
A concentration gradient is the difference in concentration of a substance between two areas.
True or False: Diffusion is a passive process.
True
Fill in the blank: Diffusion is the movement of particles from an area of ______ concentration to an area of ______ concentration.
higher, lower
How does temperature affect the rate of diffusion?
Higher temperatures generally increase the rate of diffusion.
What role does the concentration gradient play in the process of diffusion?
The concentration gradient drives the movement of particles from areas of higher concentration to areas of lower concentration.
What is the relationship between temperature and the rate of diffusion?
As temperature increases, the rate of diffusion also increases.
How does the size of particles affect the rate of diffusion?
Smaller particles diffuse faster than larger ones.
True or False: Diffusion occurs faster in gases compared to liquids.
True
What role does concentration gradient play in diffusion?
A steeper concentration gradient leads to faster diffusion.
Fill in the blank: The _______ the distance, the slower the rate of diffusion.
greater
What is the key difference between active transport and facilitated diffusion?
Active transport requires energy input to move molecules against their concentration gradient, while facilitated diffusion does not require energy and moves molecules along their concentration gradient.
True or False: Active transport always moves molecules against their concentration gradient.
True
Which type of transport process requires the use of transport proteins: active transport or facilitated diffusion?
Facilitated diffusion
What is an example of a molecule that is typically transported through active transport?
Sodium ions (Na+)
What is osmosis?
The movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
True or False: In osmosis, water moves from an area of higher solute concentration to an area of lower solute concentration.
False
Fill in the blank: Osmosis is the movement of ________ molecules across a selectively permeable membrane.
water
What does it mean for a solution to be hypertonic?
A solution with a higher concentration of solutes compared to another solution.
Which way does water move in relation to a hypertonic solution?
Water moves out of the cell into the hypertonic solution.
What is the definition of a hypotonic solution?
A solution with a lower concentration of solutes compared to another solution.
True or False: In a hypotonic solution, water moves into the cell causing it to swell.
True
What happens to a red blood cell in a hypotonic solution?
It will swell and potentially burst due to water entering the cell.
What is the definition of an isotonic solution?
A solution with the same concentration of solutes compared to another solution.
True or False: In an isotonic solution, there is no net movement of water into or out of the cell.
True
True or False: Phagocytosis is a form of endocytosis.
True
Fill in the blank: Phagocytosis is carried out by specialized cells called _______.
Phagocytes
What is exocytosis?
Exocytosis is the process by which cells release substances outside of the cell through fusion of vesicles with the plasma membrane.
True or False: Exocytosis is an active transport process.
True
Fill in the blank: Exocytosis is the opposite process of ____________.
Endocytosis
