Cell Membrane and Transport Mechanisms

The video explains active transport, a process where molecules move across a cell membrane from low to high concentration, requiring energy. It uses an analogy of heat particles to illustrate the concept. The video details the mechanism involving carrier proteins and ATP, and provides examples like muscle contraction. It also covers the sodium-potassium pump, highlighting its role in maintaining membrane potential.

What is the primary function of the cell membrane?

• To store genetic information

• To control what enters and exits the cell

• To provide energy to the cell

• To produce proteins

Which process involves molecules moving from high to low concentration without energy?

• Active transport

• Facilitated diffusion

• Simple diffusion

• Osmosis

What is required for active transport to occur?

• Channel proteins

• A concentration gradient

• Osmosis

• Energy in the form of ATP

Which type of protein is involved in both facilitated diffusion and active transport?

• Channel protein

• Carrier protein

• Receptor protein

• Enzyme

Why is calcium important for muscle contraction?

• It triggers the contraction process

• It is a structural component of muscles

• It provides energy for contraction

• It acts as a neurotransmitter

What role does ATP play in active transport?

• It acts as a channel for molecules

• It provides the energy needed for transport

• It forms the concentration gradient

• It binds to molecules for transport

What is the main function of the sodium-potassium pump?

• To store calcium ions

• To synthesize proteins

• To maintain the cell's membrane potential

• To transport glucose into the cell

How many sodium ions are moved out of the cell by the sodium-potassium pump?

• Four

• Three

• Two

• One

What is the ratio of sodium to potassium ions moved by the sodium-potassium pump?

• 3:1

• 1:1

• 2:1

• 3:2

Why does the cell prefer to have more potassium inside and more sodium outside?

• To maintain osmotic balance

• To facilitate protein synthesis

• To maintain membrane potential

• To store energy