CELS-4-hard – Churner

Which of the following statements about membrane proteins is true?

Transport proteins only facilitate passive movement of molecules and are never involved in active transport

Glycoproteins are primarily involved in signal transduction rather than cell recognition

Intercellular joining proteins facilitate direct cell-to-cell attachment, while some membrane proteins anchor the cell to the extracellular matrix

All membrane proteins are permanently fixed in place within the bilayer and cannot move laterally

None

Which of the following statements is true about passive transport?

It allows hydrophilic molecules to cross freely without proteins

It moves molecules down their concentration gradient without using energy

It moves molecules against their concentration gradient

It requires ATP to function efficiently

None

Which of the following is NOT a function of membrane proteins?

Passive diffusion of small non-polar molecules

Cell recognition

Intercellular joining

Signal transduction

None

Which of the following statements about membrane fluidity is false?

Cholesterol helps stabilize membrane fluidity under different temperature conditions

The degree of saturation of fatty acids influences membrane fluidity

Unsaturated fatty acids increase membrane fluidity by preventing tight packing

Phospholipids are static and do not move within the bilayer

None

The plasma membrane consists of a ______ bilayer, where the hydrophilic ______ face outward, and the ______ are oriented inward.

Carbohydrate lipid; heads; phosphate heads

Phospholipid; tails; fatty acid tails

Protein; fatty acids; cholesterol molecules

Phospholipid; heads; hydrophobic tails

None

Active transport is different from passive transport because it:

Moves molecules down their concentration gradient

Occurs only in prokaryotic cells

Requires ATP to move molecules against their concentration gradient

Allows substances to pass freely without energy input

None

Which of the following is false regarding membrane transport?

Passive transport does not require energy and moves molecules down their concentration gradient

Facilitated diffusion requires carrier proteins but does not use ATP

Osmosis requires ATP to move water across the plasma membrane

Active transport requires ATP to move molecules against their gradient

None

Co-transport differs from simple diffusion in that:

It requires ATP for direct energy expenditure

It only occurs in bacterial cells

It uses the gradient of one molecule to drive the movement of another

It transports molecules down their concentration gradient without assistance

None

The plasma membrane is essential for cellular function because it:

is composed of a rigid phospholipid bilayer that maintains a fixed structure.

Forms a completely impermeable barrier, preventing any molecular exchange

Consists entirely of proteins that regulate molecular transport.

Is selectively permeable, regulating molecular movement while maintaining internal conditions.

None

10.

Facilitated diffusion requires ______, which help transport ______ molecules across the membrane, but does not require ______.

Channel proteins; water-soluble; ADP

Aquaporins; hydrophobic; membrane proteins

Carrier proteins; hydrophilic; ATP

Ribosomes; charged; cholesterol

None