Cellular Transport Quiz25f

When a drop of food dye is placed in a flask of water, the dye molecules spread slowly through the entire volume of the water until they are evenly distributed. Name this type of transport.

• a. diffusion
• b. osmosis
• c. molecular pumps
• d. facilitated diffusion

The cell membrane is described as a bilayer because it consists of:

• A) Two layers of proteins
• B) Two layers of phospholipids
• C) Two layers of carbohydrates
• D) Two layers of nucleic acids

Process of bulk transport by which a cell takes material into the cell by infolding of the cell membrane is called ________________________.

• Diffusion
• Facilitated Transport
• Endocytosis
• Exocytosis

Diffusion is the movement of molecules from

• an area of low concentration to an area of high concentration.
• an area of high concentration to an area of low concentration.
• an area of equilibrium to an area of high concentration
• d. all of the above

What type of molecules can pass through the cell membrane without the help of transport proteins?

• A) Large, charged molecules
• B) Small, nonpolar molecules like oxygen and carbon dioxide
• C) Ions like sodium and potassium
• D) Glucose and amino acids

Which of the following structures serves as the cell’s boundary from its environment? - thin, flexible barrier around a cell; regulates what enters and leaves the cell

• mitochondrion
• cell membrane
• chloroplast
• channel proteins

During passive transport, molecules move from an area of ____________ concentration to an area of ____________ concentration.

• higher, lower
• lower, higher
• higher, the same
• lower, the same

The cell membrane is often described as a fluid mosaic because:

• A) It is made of solid, rigid structures
• B) It has a fixed shape and does not move
• C) Its components, like lipids and proteins, move freely within the layer
• D) It is completely permeable to all substances

What is the function of cholesterol in the cell membrane?

• A) Provides energy for active transport
• B) Helps maintain fluidity and stability
• C) Facilitates diffusion of ions
• D) Attaches carbohydrates to proteins

What part of a phospholipid is hydrophobic?

• A) Phosphate head
• B) Lipid tail
• C) Protein channel
• D) Carbohydrate chain