Cell Transport

What is the definition of OSMOSIS?

• Diffusion of water through a selectively permeable membrane

• Molecular structure that surrounds the cell and controls what enters and leaves the cell

• Movement of molecules across the cell membrane against the concentration gradient

• Movement of molecules across the cell membrane from an area of high concentration to low concentration

What is the definition of ACTIVE TRANSPORT?

• Movement of molecules across the cell membrane against the concentration gradient

• Diffusion of water through a selectively permeable membrane

• Molecular structure that surrounds the cell and controls what enters and leaves the cell

• Movement of molecules across the cell membrane from an area of high concentration to low concentration

In passive diffusion, substances always move...

• from an area of higher concentration to an area of lower concentration

• from an area with more of the molecules to an area with fewer of the molecules

• from an area of lower concentration to an area of higher concentration

• from an area with fewer of the molecules to an area with more of the molecules

Active transport requires ______, moves materials from __________________, and goes _______ the concentration gradient.

• No energy, low to high, against
• ATP, high to low, with
• ATP, low to high, with
• ATP, low to high, against

Two examples of passive transport are

• Endocytosis and Exocytosis

• Diffusion and Osmosis

• Endocytosis and Diffusion

• Facilitated Diffusion and Pinocytosis

The cell below is in a _________ solution.

• Hypotonic
• Hypertonic
• Isotonic

The cell below is in a _____________ solution.

• Hypertonic
• Hypotonic
• Isotonic

This cell organelle helps organisms maintain homeostasis by controlling what substances may enter or leave cells.

• vacuole
• nucleus
• cell membrane
• cell wall

___ is reached when there are stable internal and external cell conditions.

• Energy

• Active transport

• Homeostasis

• Passive transport

Some students used vinegar to dissolve away the shells of three eggs and used these eggs as models of human red blood cells. The students observed the changes in the eggs when they were placed in different solutions.

Which Statement best describes the role of the cell membrane in this model?

• The cell membrane is an impermeable barrier that prevents water from entering the cell.

• The cell membrane allows solutes to enter the cell, which causes the cell to shrink.

• The cell membrane allows water to enter and leave the cell.

• The cell membrane removes solutes from the environment.