1.3 Transport In Cells Flashcards
What is diffusion?
The net movement of particles from an area of higher concentration to an area of lower concentration
What are the main factors that affect the rate of diffusion?
-Concentration gradient
-Temperature
-Surface area
How are singled-celled organisms adapted for diffusion?
They have a large surface area to volume ratio - maximises the rate of diffusion of molecules to meet the organisms needs
How is the surface area to volume ratio calculated?
Surface area = Number of Sides x ( Side x Length x Side Width)
Volume = Length x Width x Depth
Ratio = Surface Area:Volume
What are 4 factors increase the effectives of a gas exchange surface?
-Large surface area
-Thin membrane
-Efficient blood supply
-Ventilation
What is osmosis?
The movement of water from the dilute solution to a concentrated solution through partially permeable membrane.
What is meant when a solution is isotonic to a cell?
The concentration of the external and internal solutions are the same
What is meant when a solution is a hypertonic to cell?
The concentration of an external solution is higher than that of an internal solution.
What may happen when an animal cell is placed in a very hypotonic solution?
Water moves into the cell, causing it to burst
What may happen when an animal cell is placed in a very hypertonic solution?
Water moves out of the cell, causing it to shrivel up.
How do you plant leaves and stems remain rigid?
Turgor pressure - water moves in by osmosis causing the vacuole to swell and the cytoplasm to press against the cell wall
What is an active transport?
The movement of molecules from a more dilute solution to more concentrated solution against a concentration gradient, using energy from respiration
How do you plant root hair cells use active transport?
Root hair cells is active transport to take up mineral irons from a more dilute solution in soils. Irons such as magnesium and nitrates are required for a healthy growth.
How is active transport used to absorb the products of digestion?
Active transport is used to transport glucose from a lower concentration in the got to a higher concentration in the blood. Glucose is the transported to the tissues where it can be used in respiration.
