please answer all parts of the question 1. In this problem, we will develop macr
ID: 257364 • Letter: P
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please answer all parts of the question
1. In this problem, we will develop macroscopic analogies to mechanical components in the cell, in order to get a better feel for the scales involved. You may need to look up some numbers as you go. Show your calculations and indicate any additional values used Imagine scaling up a typical eukaryotic cell (let's say a fibroblast, to be concrete) and all its constituent parts to the size of a large house (roughly 15m across) (a) First we'll consider the nucleus and the genome in this analogy i. In terms of size, the nucleus of the cell will resemble which of the following in ii. In terms of its thickness, the DNA chain in this analogy will resemble: a thread ii. What total length of analogous chain must fit inside this house to represent your imaginary house: a marble, a basketball, a chair, a room? a piece of spaghetti, an extension cord, a snake, or a plumbing pipe? the entire human genome? Give an approximate example of a comparable macroscopic distance (e.g.: the length of the UCSD campus) iv. Nucleosomes, in this analogy, will most closely resemble: a grain of sand, a v. Consider what would happen if you wrapped a strand of raw spaghetti twice al differences between DNA and spaghetti that marble, a basketball, a chair? around a marble, like DNA around a nucleosome. How does a cell manage to do this? Comment on the m make this possible and explain where the energy for such deformation comes rom (b) Now consider the rest of the cell. i. What will be the diameter of a microtubule in this analogy? ii. In our analogy, the thickness of the cell membrane would be comparable to: a sheet of paper, a notebook, a wall? Page 1 of4 Physics 177/277 Problem Set 1 Due 4/12/2017 ii. Mitochondria in our analogy would be roughly the size of: a marble, a basket- ball, a chair, a room?Explanation / Answer
a. i. nucleus of a cell will resemble the size of a room. in a typical animal cell of 50 micro meters, the size of the nucleus will be approximately 7 micrometers.
ii. In terms of thickness the DNA chain in this analogy resemble a spaghetti. the diameter of the DNA will be 2 nanometer in a typical living cell.
iii. the total length of analogous chain that must fit inside this analogous house must be approximately equal to the size of the area of a big country like china. because the total length of DNA of a human cell is roughly 3 meters.
iv. Nucleosomes in this analogy will closely resemble to the size of a marble. because the diameter of a nucleosome in a living cell is about 11 nanometers.
v. The DNA wraps around the histone octamers of nucleosomes. this happens because of the acidic nature of DNA and basic nature of histone proteins, which attract with each other. the difference between the DNA and spaghetti in terms of mechanical properties is the spaghetti does not tightly bound to the marble, whereas the DNA binds tightly to the histone octamer due to its acidic nature.
(b) i. the diameter of the microtubule in this analogy can be equal to an extension cord. because the diameter of a microtubule in a living cell is about 25 nanometers.
ii. the thickness of the cell membrane will be equivalent to the notebook in our analogy. because the thickness of the cell membrane is about 10 nanometers in the living cell.
iii. mitochondria in our analogy will be roughly equivalent to the size of a tiny room. because the size of a mitochondria in a living cell range from 0.5 to10 micrometers.
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