The membranes of winter wheat are able to remain fluid when it is extremely cold by _____.
The idea that a just government must derive its powers from the approval of the people it governs. Tadpoles are larger than tadpoles.
How do the membranes of winter wheat cells remain fluid when it is extremely cold?
Many plants can adapt to temperature changes by changing the ratio of unsaturated to saturated fatty acids in their cell membranes. For example, as winter approaches, winter wheat increases the percent of unsaturated phospholipids, which prevents membranes from freezing and maintains fluidity.
When a cell is in equilibrium with its environment which of the following occurs for substances that can diffuse through the cell A There is random movement of substances into and out of the cell B there is directed movement of substances into and out of the cell C there is no movement of substances into?
Diffusion is the net movement of a substance from a region of higher concentration to a region of lower concentration. A concentration gradient is created by the difference in concentration between two environments, which drives diffusion.
When biological membranes are frozen and then fractured They tend to break along the middle of the bilayer The best explanation for this is that *?
The best explanation for why biological membranes tend to break along the middle of the bilayer when frozen and then fractured is that. C) hydrophilic interactions between the opposite membrane surfaces are destroyed when membranes are frozen and then fractured.
How do unsaturated fatty acids help keep any membrane more fluid at lower temperatures quizlet?
The double bonds in unsaturated fatty acids form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly together at lower temperatures, and weak hydrophobic interactions in the interior of the membrane are easily disrupted.
Why do unsaturated fatty acids help keep a membrane more fluid?
When unsaturated fatty acids are compressed, the “kinks” in their tails push adjacent phospholipid molecules away, allowing the membrane to remain fluid. Cholesterol acts as a buffer, preventing lower temperatures from inhibiting fluidity and higher temperatures from increasing fluidity.
Why are lipids and proteins free to move laterally in membranes?
The double bonds cause kinks in the fatty acid tails, preventing adjacent lipids from packing tightly together. Why are lipids and proteins free to move around in membranes? The interior of the membrane has only weak hydrophobic interactions.
Does the net movement of molecules slow down as equilibrium is reached?
The movement of molecules does not stop at equilibrium, and the movement of materials in both directions is equal.
What is the movement of water across the plasma membrane called?
The net movement of water across a selectively permeable membrane is osmosis, which is caused by a difference in solute concentrations on both sides of the membrane.
Which of the following results is most likely when a plant cell is submerged in hypertonic solution?
When a plant cell is submerged in a hypertonic solution, which of the following outcomes is most likely? Plasmolysis shrinks the interior of the cell.
What would likely move through the phospholipid bilayer the most easily?
CO2 is likely to travel through the lipid bilayer at a much faster rate than the other molecules.
When a membrane is freeze-fractured the bilayer splits down the middle between the two layers?
When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. The bumps seen on the fractured surface of a freeze-fractured membrane in an electron micrograph are: Integral proteins.
When a membrane is freeze-fractured the bilayer splits?
The bilayer splits down the middle between the two layers of phospholipids when a membrane is freeze-fractured.
Which of the following is a reasonable exclamation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures?
The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly. Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures?
Which of the following is an explanation of why saturated fatty acids keep membranes less fluid at higher temperatures?
Saturated fatty acids reduce the fluidity of a membrane; if only saturated fatty acids are available, the membrane’s transition temperature rises until it reaches ambient temperature, at which point the membrane becomes a gel.
What factors increase membrane fluidity?
Let’s look at the variables that affect membrane fluidity now!
- Factor #1: The length of the fatty acid tail, which influences membrane fluidity.
- Factor #2: Temperature.
- Factor #3: Cholesterol content of the bilayer.
- Factor #4: The degree of saturation of the fatty acid tails.