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Flashcards in B3 Deck (13):

What is the definition of diffusion?

Diffusion is the random movement of particles from an area of high concentration to an area of low concentration


What is meant by concentration gradient?

A concentration gradient is a difference in the concentration of a substance between one area and another. A steep concentration gradient = a large difference in concentration


What is the definition of osmosis?

Osmosis is the diffusion of water from a dilute solution to a more concentrated solution through a partially permeable membrane


What is a partially permeable membrane?

A partially permeable membrane allows water molecules through but not other molecules


What happens when a plant cell is placed in pure water?

Pure water has a higher concentration of water than the cytoplasm of a cell. Water would enter the cell by osmosis. The plant cell wall prevents the cell from bursting.


Why do sports drinks contain sugar?

Sports drinks contain sugars to replace the sugar used in energy release by respiration during exercise


What happens if the ions and water lost during exercise are not replaced?

Sports drinks contain ions and water to replace the ions and water lost from sweating during exercise.


What is meant by active transport?

Active transport is the movement of substances from a low concentration to a high concentration (against the concentration gradient) using energy from respiration.


Why is active transport important in living organisms?

Active transport allows cells to absorb ions from a dilute solution.


How are soluble food molecules absorbed by villi in the small intestine?

Soluble food molecules are absorbed by villi in the small intestine by diffusion and active transport.


How are the lungs protected?

The lungs are protected by the ribcage.


What do we call the movement of air into and out of the lungs?

The movement of air into and out of the lungs is called ventilation.


How does carbon dioxide enter the leaves of plants?

Carbon dioxide enters the leaves of plants by diffusion. The leaves of plants by diffusion. The concentration inside the leaves is low as the cells use it in photosynthesis.