Q. What are the instructions that come from the nucleus to the ribosomes?
They receive their “orders” for protein synthesis from the nucleus where the DNA is transcribed into messenger RNA (mRNA). This mRNA travels to the ribosomes, which translate the code provided by the sequence of the nitrogenous bases in the mRNA into a specific order of amino acids in a protein.
Q. Where do ribosomes get their instructions?
Protein synthesis Synthesis of new proteins starts in the nucleus, where ribosomes get their instruction to begin the process. Sections of DNA (genes), encoding a specific protein, are copied over to messenger RNA (mRNA) strands in a process called transcription.
Q. Which is a mechanism for restricting the movement of proteins in the plasma membrane quizlet?
To restrict the movement of proteins in the plasma membrane, the proteins can be tethered to structures outside the cell, such as molecules in the extracellular matrix or on an adjacent cell, or to relatively immobile structures inside the cell, such as the cell cortex.
Q. Which membrane would show a more rapid recovery?
The FRAP curve for lipids would show a much more rapid recovery but only reach about 50% of the initial levels of fluorescence. The FRAP curve for lipids would show a much more rapid recovery to initial levels of fluorescence.
Q. What type of diffusion is the slowest concerning the movement of phospholipids in a membrane?
Because the hydrophobic core of a typical cell membrane is 100 – 1000 times more viscous than water, the diffusion rate of all substances across a phospholipid membrane is very much slower than the diffusion rate of the same molecule in water.
Q. Do proteins move in the plane of the membrane?
Like membrane lipids, membrane proteins do not tumble (flip-flop) across the lipid bilayer, but they do rotate about an axis perpendicular to the plane of the bilayer (rotational diffusion). In addition, many membrane proteins are able to move laterally within the membrane (lateral diffusion).
