Movement in and out of cells Flashcards
What is diffusion?
the movement of molecules from the region of high concentration to the region of low concentration down the concentration gradient
What is osmosis?
the movement of water molecules from a region of high water potential to a region of low water potential down the water potential gradient through a semi permeable membrane.
What is active transport?
the movement of molecules against a concentration gradient using energy for respiration. Molecules are actively transported through a cell membrane from a region of low concentration to a region of high concentration
What is meant by the word “Turgid”
cells are described as turgid when they are swollen due to high water content.
What is meant by turgor pressure?
the pressure on the cell wall from the cell membrane pushing upon it. this is a result of the cell becoming turgid as water moves into the cell via osmosis.
What is meant by “Plasmolysis”
plasmolysis occurs when there is too little water in the cells. In plant cells, the cell membrane peels away from the cell wall.
What are carrier proteins and what do they do?
carrier proteins facilitate active transport. They are embedded in the cell membrane and allow passage through it. Molecules from the side with low concentration bind to the carrier proteins then changes shape using energy from respiration. This forces the molecules to move through the membrane to the side with high concentration, where it is then released.
explain the uptake of water in plants
water moves in and out of the cells through the cell membranes via osmosis. Water is important to provide support for the cell structure through maintaining turgor pressure. It also provides a medium in which metabolic reactions occur, Water has a high specific heat capacity, thus acts as a temperature buffer. This is important as it maintains the optimum temperature for enzyme reactions.
How do root hair cells take in ions and nitrates. Use and mention active transport.
plants take up ions such as nitrates and magnesium from the soil via the root hair cells. The concentration of ions in the root hair cells is greater than the concentration of ions in the soil. Energy from respiration is therefore used to transport ions into the cell against the concentration gradient.
how does the body take in glucose?
glucose is taken up in the small intestine and kidney tubules. Glucose moves against the concentration gradient through carrier proteins.
