Transport Mechanisms in Cells

In this video, Mr. Poser, the AP Biology teacher, reviews the mechanisms of transport in cells, focusing on passive transport, facilitated diffusion, and active transport. Passive transport involves diffusion across the cell membrane without energy, while facilitated diffusion requires membrane proteins to help small charged or polar molecules pass through. Active transport, which moves molecules against the concentration gradient, requires energy and membrane proteins. The video also covers specific types of active transport, including electrogenic pumps, co-transport, and processes like endocytosis and exocytosis.

What are the three main types of transport mechanisms discussed in the video?

• Facilitated diffusion, osmosis, and active transport

• Passive transport, active transport, and facilitated diffusion

• Osmosis, diffusion, and active transport

• Endocytosis, exocytosis, and passive transport

Which type of molecules typically move through passive transport?

• Proteins and nucleic acids

• Small nonpolar molecules

• Large polar molecules

• Ions and charged particles

What is a key characteristic of passive transport?

• It requires no energy

• It moves molecules against the concentration gradient

• It requires energy

• It involves membrane proteins

Facilitated diffusion is necessary for which type of molecules?

• Small charged or polar molecules

• Large nonpolar molecules

• Large charged molecules

• Small nonpolar molecules

What role do membrane proteins play in facilitated diffusion?

• They create a concentration gradient

• They break down molecules

• They act as channels or carriers

• They provide energy for transport

Active transport is characterized by which of the following?

• Facilitated by channel proteins

• Movement with the concentration gradient

• Use of ATP and membrane proteins

• No energy requirement

Which of the following is an example of active transport?

• Osmosis of water

• Sodium-potassium pump

• Facilitated diffusion of glucose

• Diffusion of oxygen

What is the function of electrogenic pumps in active transport?

• They break down ATP

• They facilitate passive transport

• They generate voltage across membranes

• They transport water molecules

What is the main difference between exocytosis and endocytosis?

• Exocytosis is passive, endocytosis is active

• Exocytosis involves secretion of molecules, endocytosis involves intake

• Exocytosis requires energy, endocytosis does not

• Exocytosis involves intake of molecules, endocytosis involves secretion

Which process involves the cell 'drinking' smaller liquid particles?

• Pinocytosis

• Exocytosis

• Facilitated diffusion

• Phagocytosis