SAT II Biology M : Other Cell Functions

Study concepts, example questions & explanations for SAT II Biology M

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Example Questions

Example Question #1 : Other Cell Functions

Which of the following types of transport require ATP?

Possible Answers:

The Na+/Kpump releasing 3 sodium ions outside of the cell and 2 potassium ions into the cell

Sodium ions moving from an area of high concentration to an area of low concentration through a voltage-gated sodium channel

Glucose moving into the cell, down its concentration gradient, through a channel

Water moving down its concentration gradient through an aquaporin

Water moving from an area of low solute concentration to an area of high solute concentration

Correct answer:

The Na+/Kpump releasing 3 sodium ions outside of the cell and 2 potassium ions into the cell

Explanation:

The Na+/K+ pump is active transport and therefore requires ATP. Since the pump is moving ions against its concentration gradient, it requires ATP to change the conformation of the pump to release the ions. All of the other forms of transport are either diffusion (moving down its concentration gradient) or facilitated diffusion (moving down its concentration gradient with the help of a channel or carrier). 

Good tip: Pumps are used for active transport while carrier proteins or channels are used for facilitated diffusion which is a type of passive transport.

Example Question #2 : Other Cell Functions

All of the following are a part of the Cell Theory EXCEPT __________.

Possible Answers:

cells arise from nonliving substances

all living things are made up of cells

the cell is the basic building block of life

cells carry genetic information

the chemical reactions necessary for life take place in the cell

Correct answer:

cells arise from nonliving substances

Explanation:

Cells do not arise from nonliving substances, though scientists used to believe they did. Through several experiments by many different scientists, it became clear that indeed all cells arise from preexisting cells.

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