Active and Passive Transport Concepts

Mr. Messina presents a biology lesson on protein structures that facilitate molecule movement across cell membranes. The video covers the structure of cell membranes, including phospholipids and proteins, and explains how different molecules, such as hydrophobic and polar molecules, move through membranes. It distinguishes between passive transport, including facilitated diffusion, and active transport, which requires energy in the form of ATP. The video also discusses endocytosis and exocytosis, processes that cells use to bring substances in and out. The lesson concludes with a summary of these transport mechanisms.

What is the main component of the cell membrane?

• Carbohydrates

• Nucleic acids

• Proteins

• Phospholipids

Which part of the phospholipid is hydrophilic?

• Fatty acid tails

• Phosphate head

• Both tails and head

• Neither tails nor head

Which type of molecules can pass through the cell membrane without any issues?

• Large uncharged particles

• Proteins

• Small uncharged polar molecules

• Ions

What is the main characteristic of facilitated diffusion?

• It requires energy

• It moves molecules against the concentration gradient

• It requires protein channels

• It is a form of active transport

What is the term for the shape change in proteins during active transport?

• Protein folding

• Molecular alteration

• Structural shift

• Conformational change

What is the main difference between passive and active transport?

• Active transport moves molecules against the concentration gradient

• Passive transport moves molecules from low to high concentration

• Active transport does not require energy

• Passive transport requires energy

What does endocytosis involve?

• Expelling substances out of the cell

• Bringing substances into the cell

• Moving substances along the concentration gradient

• Releasing energy in the form of ATP

Which organelle is responsible for producing vesicles for exocytosis?

• Nucleus

• Endoplasmic reticulum

• Golgi apparatus

• Mitochondria

What type of molecules move through simple diffusion?

• Ions

• Large charged particles

• Nonpolar hydrophobic molecules

• Polar hydrophilic molecules

Which transport mechanism requires ATP?

• Osmosis

• Simple diffusion

• Facilitated diffusion

• Active transport