Question

cells have receptors both inside the cell and in the cell membrane. recall that some molecules can easily cross the cell membrane, but others cannot. molecules that can cross the membrane bind to receptors inside the cell. molecules that cannot cross the membrane bind to receptors in the membrane. when the signal binds to a receptor, the receptor changes its shape. other molecules inside the cell respond to the changing shape of the receptor. the signal molecule itself never enters the cell. how does a receptor in the membrane transmit a message to the cell? 3.3 vocabulary check cell membrane phospholipid fluid mosaic model selective permeability receptor mark it up go back and highlight each sentence that has a vocabulary word in bold. circle the correct word from the choices below. 1. which material has selective permeability, a sponge or a shovel? 2. which contains the other, cell membrane or phospholipid? 3. which receives signals, a fluid mosaic model or a receptor? 3.3 the big picture 4. what does the cell membrane do for the cell? 5. describe how the phospholipids are arranged in the cell membrane. 6. do cells respond to every signal? explain. 7. explain how a tea bag is an example of selective permeability.

Explanation:

Step1: Recall cell - membrane properties

The cell membrane has selective permeability. Phospholipids are components of the cell membrane. A sponge and a shovel do not have selective permeability. So the answer to question 1 is cell membrane.

Step2: Understand cell - membrane composition

The cell membrane contains receptors. The fluid - mosaic model is a model of the cell membrane structure, not something that contains a receptor. So the cell membrane contains the receptor for question 2.

Step3: Identify signal - receiving component

Receptors receive signals. The fluid - mosaic model is a description of the cell - membrane structure, not a signal - receiving entity. So the receptor receives signals for question 3.

Step4: Summarize cell - membrane function

The cell membrane controls what enters and leaves the cell, provides protection and support, and is involved in cell - signaling.

Step5: Describe phospholipid arrangement

Phospholipids are arranged in a bilayer in the cell membrane, with the hydrophilic heads facing outward and the hydrophobic tails facing inward.

Step6: Analyze cell - signal response

Cells do not respond to every signal. They only respond to signals for which they have specific receptors.

Step7: Explain tea - bag as an example

A tea - bag is an example of selective permeability because water can pass through the pores of the tea - bag to extract the tea compounds, but the tea leaves themselves are retained inside the bag.

Answer:

1. cell membrane
2. cell membrane
3. receptor
4. Controls what enters and leaves the cell, provides protection and support, and is involved in cell - signaling.
5. Arranged in a bilayer with hydrophilic heads facing outward and hydrophobic tails facing inward.
6. No, they only respond to signals for which they have specific receptors.
7. Water can pass through the pores of the tea - bag to extract the tea compounds, but the tea leaves themselves are retained inside the bag.