B1:Cell Transport Flashcards
(15 cards)
What is diffusion?
The spreading out of the particles of any substance in a solution, or particles of a gas, causing a net movement from an area of higher concentration to an area of lower concentration
What substances in animals and plants are transported in and out of cells by diffusion?
Oxygen, carbon dioxide and urea
How does the difference in concentration affect the rate of diffusion?
Increased concentration gradient increases the rate of diffusion
How does the temperature affect the rate of diffusion?
Increased temperature increases the rate of diffusion because particles have more kinetic energy and are moving faster
How does the surface area of the membrane affect the rate of diffusion?
Increased surface area increases the rate of diffusion.
How are single cells organisms adapted for diffusion?
It has a large surface area to volume ratio
How is the small intestine adapted for exchange?
It is long and has villi for a large surface area, the cell membranes are thin for a short diffusion pathway, there is a rich blood supply to maintain a steep concentration gradient and lots of mitochondria
How are the lungs adapted for exchange?
Lots of alveoli for a large surface area, thin membrane for a short diffusion pathway and good ventilation and blood supply to maintain a steep concentration gradient
How are the gills in a fish adapted for exchange?
Large surface area, thin membrane for a short diffusion pathway and good ventilation and blood supply to maintain a steep concentration gradient
How are the roots adapted for exchange?
Large surface area, thin surface membrane for a short diffusion pathway and lots of mitochondria for active transport
How are the leaves adapted for exchange?
Large surface area and thin for short diffusion pathway
What is osmosis?
The movement of water from a dilute to concentrated solution through a partially permeable membrane
What is active transport?
The movement of substances from a more dilute solution to a more concentrated solution (against the concentration gradient). It requires energy.
What is an example of active transport in animals?
Absorption of sugar in the gut from a low to high concentration
What is an example of active transport in plants?
Absorption of mineral ions into plant root hairs
