Cell Membrane Structure and Passive transport/Osmosis review

What is the function of the hydrophilic 'head' of a phospholipid in the cell membrane?

• It repels water

• It interacts with water

• It does not interact with water

• It forms a single layer

What does the term 'semi-permeable' mean in the context of the cell membrane?

• All molecules can pass through

• No molecules can pass through

• Some molecules can pass through easily, others cannot

• Only water can pass through

Tags

NGSS.HS-LS2-3

Fill in the blank: Integral (channel) proteins provide a ______ to allow certain molecules/substances to pass through the cell membrane.

• pathway

• barrier

• signal

• charge

Osmosis is facilitated diffusion of water molecules (H2O) using an _______.

• aquaporin

• enzyme

• lipid bilayer

• carrier protein

What happens when water tries to diffuse across the cell membrane without an aquaporin?

• Water is repelled by the hydrophobic tails

• Water passes through easily

• Water is attracted by the hydrophilic heads

• Water is converted to another substance

What is the role of aquaporin in water diffusion across the cell membrane?

• It blocks water from passing

• It allows water to avoid the hydrophobic tails

• It converts water to another substance

• It repels water

Why must the hydrophilic heads of the phospholipid bilayer face the outside and inside of the cell?

• To repel water

• To attract water and interact with the cytosol

• To form a single layer

• To block all molecules

Arrangement #2: If the hydrophobic tails face the outside of the cell, what would happen?

• A) Water would enter the cell easily

• B) Water would not be able to enter the cell

• C) The cytosol would attract water

• D) The cell would become permeable to all substances

According to the fluid mosaic model, what is the cell membrane made up of?

• A) A single layer of phospholipid molecules

• B) A bilayer of phospholipid molecules

• C) A layer of protein molecules

• D) A layer of carbohydrate molecules

Fill in the blank: The cell membrane is ______ because phospholipids and proteins move freely and fluidly and slide past one another.

• flexible

• rigid

• sticky

• fragile