Cell Membrane Transport Quiz

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Questions and Answers

What type of transport does not require energy and occurs down a concentration gradient?

Endocytosis

Active transport

Phagocytosis

Facilitated diffusion (correct)

What is the primary energy source used in active transport?

Lipids

Nucleotides

Adenosine triphosphate (ATP) (correct)

Glucose

Which of the following describes osmosis?

Transport of substances without any membrane involvement

Active transport of ions across the membrane

Movement of molecules from high to low concentration through a semi-permeable membrane (correct)

Exocytosis of waste materials from the cell

What do transport proteins do in facilitated diffusion?

Create portals or attach to molecules for transport Signup and view all the answers

Which process allows the cell to expel sodium ions against their concentration gradient?

Active transport Signup and view all the answers

What does the fluid mosaic model describe?

The dynamic nature and structure of cell membranes. Signup and view all the answers

What role do glycoproteins and glycolipids play in cells?

They act as chemical markers and linkers between cells. Signup and view all the answers

How does cholesterol affect the cell membrane?

It increases membrane rigidity and firmness at moderate to high temperatures. Signup and view all the answers

What is a characteristic of phospholipids in the cell membrane?

They exhibit lateral movement within the same layer. Signup and view all the answers

Which of the following activities do glycoproteins participate in?

They can help in blood clotting and protection against diseases. Signup and view all the answers

What is the primary function of protein molecules in the cell membrane?

To facilitate nutrient transport and maintain cell structure Signup and view all the answers

How do carbohydrates function in the cell membrane?

They help identify the cell and link it to other cells Signup and view all the answers

What type of proteins span both layers of the cell membrane?

Transmembrane proteins that are involved in nutrient transport Signup and view all the answers

Which statement about carbohydrates in the cell membrane is correct?

They can form glycolipids and glycoproteins Signup and view all the answers

Where are carbohydrate molecules located in the cell membrane?

On the outer surface of the outermost layer of the membrane Signup and view all the answers

What is the primary function of the phospholipid bilayer in the cell membrane?

To separate the cell from its environment Signup and view all the answers

Which type of protein is responsible for transporting nutrients across the cell membrane?

Transport proteins Signup and view all the answers

What characterizes the hydrophobic tails of phospholipids in the cell membrane?

They repel water Signup and view all the answers

What role do proteins play in the cell membrane?

They can facilitate various cellular processes Signup and view all the answers

What is the characteristic of the space between the two layers of phospholipids in the cell membrane?

It is fluid-repellent and semipermeable Signup and view all the answers

Study Notes

Cell Membrane Transport

The fluid mosaic model describes how nutrients are transported into and out of the cell.
Nutrient and waste transport may be passive (doesn't require energy) or active (requires energy) to move molecules across the cell membrane.
Passive transport can occur through diffusion where molecules flow from a region of high concentration to a region of low concentration (down a concentration gradient).
If molecules diffuse through a semipermeable membrane, the process is called osmosis.
In cells, a type of assisted passive transport called facilitated diffusion works because of transport proteins, which create membrane-spanning portals for specific molecules or ions to attach to a specific side, and release it on the other side of the membrane.
In contrast, active transport is fueled by a coenzyme called adenosine triphosphate (ATP) – which delivers chemical energy captured from the breakdown of food to other parts of the cell – to move molecules up a concentration gradient.
Active transport allows the cell to expel waste ions, such as sodium (Na+), from the cell even though the concentration of sodium ions outside the cell may be higher than the concentration inside.

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Description

Test your understanding of the fluid mosaic model and the mechanisms of nutrient and waste transport across cell membranes. This quiz covers both passive and active transport, including diffusion, osmosis, and facilitated diffusion. Challenge yourself to recall how energy and transport proteins facilitate cellular processes.