What is Expression: Definition and 999 Discussions
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and small nuclear RNA (snRNA), the product is a functional non-coding RNA. Gene expression is summarized in the central dogma of molecular biology first formulated by Francis Crick in 1958, further developed in his 1970 article, and expanded by the subsequent discoveries of reverse transcription and RNA replication.The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and utilized by viruses—to generate the macromolecular machinery for life.
In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, i.e. observable trait. The genetic information stored in DNA represents the genotype, whereas the phenotype results from the "interpretation" of that information. Such phenotypes are often expressed by the synthesis of proteins that control the organism's structure and development, or that act as enzymes catalyzing specific metabolic pathways.
All steps in the gene expression process may be modulated (regulated), including the transcription, RNA splicing, translation, and post-translational modification of a protein. Regulation of gene expression gives control over the timing, location, and amount of a given gene product (protein or ncRNA) present in a cell and can have a profound effect on the cellular structure and function. Regulation of gene expression is the basis for cellular differentiation, development, morphogenesis and the versatility and adaptability of any organism. Gene regulation may therefore serve as a substrate for evolutionary change.
not actually homework, but things I need to know:
1: simplify the expression e^{a ln b} (write it in a way that dosen't involve logarithims)
i want to prove the identities:
lnab = lna + lnb
lna^b = blna
\frac{d}{dx}lnx = \frac{1}{x}
i also want to derive the useful assumption...
I'm finding the percent error in a S.R. problem and getting a really small number. How can I find the exact percentage? This is the result that needs to be simplified:
6.7x10^(-16) / (1 + 6.7x10^(-16))
If I do an order of magnitude approximation, then the bottom becomes 1, but that will...
I have been asked to simplify this one:
12x3 + 8x2 / 6x2 + 4x
By factoring it out I have simplified it to 4x2 / 2x
Is there anything I can do to simplify it further? I know the rules of dividing powers and hence if it was 4x2 / 4x I know I could simplify it to to 4x (subtract the...
How can I simplify this expression? As it is already factorised (factored) I do not see what else I can do to simplify it.
x(9x+2) / x3(x-2)
The only thing that I can think of is if I unfactorise everything to give the following:(although it doesn't seem to be very simplified from the...
I know this expression should return a Gaussian distribution but I can't get Mathematica to simplify the integral. What am I missing?
\text{Simplify}\left[\frac{\text{Product}\left[\text{PDF}\left[\text{NormalDistribution}[y,\sigma...
Hi,
Will anybody help me to find the maximum of the following expression:
|\cos^m\theta_1
(c\cos^n\theta_2+se^{i(\gamma-n\lambda_2)}\sin^n\theta_2)+e^{-im\lambda_1}\sin^m\theta_1 (\pm ce^{-in\lambda_2}\sin^n\theta_2+se^{i\gamma}\cos^n\theta_2)|^2
where m,n\ge 2 are fixed positive...
freal Loops?
Hi everybody..
I have a question.
Recently, I'm using g95 to run my Fortran 95 program.
But it occur an error, which is:
REAL expression in DO loop at <1> - to enable REAL loop parameters use -freal-loops
What is freal loop exactly?
and How to solve this problem...
Homework Statement
By first expressing the general term in partial fractions, find an expression in terms of n for
summation of r=2 to n ( 1 / (r^2 - 1) ). Hence show that summation of r=1 to n ( 1 / r^2) i less than 7/4 for all values of n
Homework Equations
The Attempt at a...
Homework Statement
Derive an expression for the total energy required to asemble a sphere of charge corresponding to a nucleus of atomic number Z and radius R. Assume the nucleus is a sphere of uniform volume charge density \rho
Homework Equations
\rho = mass / volume = 3Am / 4*pi*R3...
it is given that R1=R2
http://i43.tinypic.com/b8359w.jpg
i used voltage divider
i tried to calculate it by taking v1 as the midle poit of the left brench
and v2 as the middle point of the of the other branch
so Vout=V_s/2 -Vs[r/(r+1/jwc )=v_s/2(1-rjwc/2(rjwc+1))
i can't get the...
it is given that R1=R2
http://i43.tinypic.com/b8359w.jpg
i used voltage divider
i tried to calculate it by taking v1 as the midle poit of the left brench
and v2 as the middle point of the of the other branch
so Vout=V_s/2 -Vs[r/(r+1/jwc )=v_s/2(1-rjwc/2(rjwc+1))
i can't get the...
Homework Statement
Aqueous solutions of hypochlorous acid, HOCl, can be unstable due to the reaction:
2HOCl <--> Cl- + ClO2- + 2H+
(c) Write out the balanced reaction appropriate to basic solution corresponding to the reaction given above.
Homework Equations
K =...
Homework Statement
Write the partial fraction decomposition of the rational expression. Check your result algebraically.
(x2 – 7x + 16)/[(x + 2)(x2 – 4x + 5)]
The Attempt at a Solution
[A/(x+2)] + [(Bx+C)/(x2-4x+5)]
x2-7x+16= A(X2-4x+5)+(Bx+C)(x+2)...
Homework Statement
cos(2 * arcsin(2x))
Use a triangle to simplify each expression. Where application, state the range of x's for which the simplification holds.
Homework Equations
cos(2t) = cos^2(t) - sin^2(t) = 1-2sin^2(t) = 2cos^2(t) - 1
The Attempt at a Solution
My attempt was the...
Homework Statement
Use double-angle and addition formulæ and other relations for trigonometrical functions to find an expression for sin(3x) in terms of sin x alone.
My problem is I don't know what is meant by "find an expression for sin(3x) in terms of sin x alone.". I know the relevant...
Homework Statement
Given the luminosity profile L(r)=L0e(-r/D) and the density profile p(r) = v02/(4piGr2) find an expression for the mass-to-light ratio as a function of distance from the center of the galaxy r. Assume the ratio is unity at r = D.
The Attempt at a Solution
At first I...
When we are resolving a periodic piecewise continuous function in a fouriers series of harmonic terms, as follows: f(x)= a0/2 +Σancos nΠx/L + Σ bnsin nΠx/L, period 2L
we are essentially expressing a sectionally discontinuous function (with finite no of such finite discontinuities, if at...
Homework Statement
Consider the power series.
sigma (n=1 to infinity) x^n / [n(n+1)]
if f(x) = sigma x^n / [n(n+1)], then compute a closed-form expression for f(x).
It says: "Hint: let g(x) = x * f(x) and compute g''(x). Integrate this twice to get back to g(x) and hence derive...
Hi,
I have:
\frac{a}{b+a+s} + \frac{c*b}{(b+a+s)(c+s)}
I can rearrange that to:
\frac{a-c}{b+a-c} * \frac{b+a}{b+a+s} + \frac{b}{b+a-c} * \frac{c}{c+s}
Is this correct? If so, can someone tell me why the +s changes into a -c?
Homework Statement
Consider the vector \vec A whose origin is \vec r.
1)Express the vector \vec A in a basis of Cartesian coordinates, cylindrical and spherical ones.
2)Repeat part 1) if the origin is \vec r + \vec r_0.
Homework Equations
None given.
The Attempt at a Solution
1)In...
Homework Statement
I have two sets E and L.
I have to show that E is a subset of L, using only complement, union and the empty set.
I.e. all members of E also have to be members or L, but L may contain members not included in E.Homework Equations
The Attempt at a Solution
Am I right in...
the expression for the magnetic flux changing area is :
change in m.flux=B.dA
and for varying magnetic field
change in m.flux=dB.A
but for when the both is changing then what will the expression
Homework Statement
Sorry if the question sounds a bit off, i wasnt quite sure how to word it.
My math question is: given the expression Sn=n^2 + 2n, determine an expression, in simplified form, for Sn-1 in terms of n.
Homework Equations
NA (i don't think there are any equations for...
p = 4
q = -2
r = 3
s = -5
on that basis, evaluate this expression:
3r - 3p + 5q
I make it to be -7 (15 - 12 + (-10)
But my math book says the answer is -13. Can anyone explain where I have gone wrong?
Thanks
Homework Statement
Decompose the rational expression into a sum of partial fractions:
(x+1)/(3(x-2)2)
I am familiar with the method of decomposing fractions into a sum of partials fractions (solving for A, B, C, etc.). What is confusing me is the coefficient 3 in the denominator. Do I...
I write MATLAB program on my computer but when I copy the file to another computer and press F5 to run, there is a message 'unexpected MATLAB expression'
what should I do?
I write MATLAB program on my computer but when I copy the file to another computer and press F5 to run, there is a message 'unexpected MATLAB expression'
what should I do?
Hello,
during a calculation I got the following term:
\varepsilon^{i_1 \ldots i_n}\varepsilon_{j_1 \ldots j_n} (a_{i_1}^{j_1}\ldots a_{i_n}^{j_n})
where \varepsilon is the levi-civita symbol and a_i^j are real numbers.
Is it possible to simplify that expression?
Substitute each of the capital letters by a different digit from 0 to 9 to satisfy this set of cryptarithmetic relationships. None of the numbers can contain any leading zero.
(ABC)*(DE)=(BCD)*(BF), and:
FA+DF- CE=1
in this photo there is the circuit and the KVL of the solution
but when i tried to do the KVL
i go from the arc(3 lines represents potential zero)
in counter clockwise direction
so i get V_L + V_C+V_R-V_s=0
when i go against the direction of a current the voltage is on PLUS
when in the...
We have been doing research on the differential expression of one gene between two cell lines (A and B cell lines), with high expression in A cell line and no expression in B cell line. We found that ~250 bp in the promoter of the gene has its activity in A cell line, but no activity in B cell...
can anyone tell me how to get the real and imaginary parts of the following function :
(x+ i y)* Log( a+i b) where x, y a and b are all real numbers and i =sqrt (-1).
Thanks very much
Homework Statement
I have a quiz tomorrow and i know a problem like this is going to be on it and i need to figure out the process
Homework Equations
the expression is: (2x^2-3x+1)(4)(3x+2)^3(3)+(3x+2)^4(4x-3)
The Attempt at a Solution
i know the final answer(3x+2)^3(36x^2-37x+6)...
Homework Statement
Make a BCD 3321 encoder. So if you input 0100, the encoder will output (depending on your design) either a 1001, or a 0101. Similarly, an input of 0101 will output either a 1010 or a 0110 (again, depending on your design).Homework Equations
I know you're supposed to use...
The thin, uniformly charged rod shown in the figure below has a linear charge density λ. Find an expression for the electric potential at P. (Use k_e for ke, lambda for λ, a, b, and L as necessary.)
Homework Equations
dV=k*dq/r
lambda*dx=dq
The Attempt at a Solution
I integrated...
Hey, so I have an assignment and this is one of the questions on it, I did it but I am not sure if what I did is right.
What I did was find Ceq=(C1C2)/(C1+C2))
So then Q=CV(t)=(C1C2)/(C1+C2))V(t)
Then I found the voltage across C2=Q/C2=(C1C2)/(C1+C2))V(t)/C2=(C1)/(C1+C2))V(t)
And...
Homework Statement
I have to rewrite the following expression using a radical. I know the correct answer according to my textbook is 4x√x.
Homework Equations
4x ^{3/2} The Attempt at a Solution
√4x^3
is this the right start?
Homework Statement
A small sphere carrying a charge of q with mass m is suspended from point A by a massless thread of length L, as shown in the figure. A second sphere carrying a charge of 2q with mass M is suspended from a fixed rod from point B. The distance between A and B is equal to...
I've recently come across a http://technologyinterface.nmsu.edu/Spring08/" for why power is maximised in a component when its resistance R_L equals the internal resistance R.
But in part (5) of method 1, we need to find the minimum non-negative value that the expression k+k^-^1 can take. For...
Homework Statement
Rewrite the following expression as a single product.
Hint: Perform a change of variable first.
Homework Equations
The Attempt at a Solution
I looked at the example from the book regarding a change of variable. They first started out by calculating the upper and lower...
The problem is to find a closed form for the expectation (mu) and standard deviation (sigma) of the probability density function underneath (Maple notation):
f(t) = a*exp(a*t)*BesselK(0, 2*sqrt(exp(a*t)))/BesselK(1, 2)
I was able to find an expression for mu::
mu =...
Hi
I have seen the expression for mass flow rate in one of the problems I am working on. I used to simply apply the expression for calculating the mass flow rate with respect to the position as (ρu + (∂u ∕∂x)dx) dy dz). ρ, u are density and velocity component respectively.
I would like to...
Hi all.
I´m looking for an expression for displacement of the waveform, eta(x,y,t) , of a circular wave that is created when a stone is dropped into a pond. Simplest case, assuming an ideal fluid and neglecting non-linear effects.
Thanks,
/scepter
I have been trying to do this problem for a long time, and still can not do it. I know the answer is sin2x, but I have no idea how to do it:
write expression as sine, cosine, or tangent of an angle
sin3xcosx - cos3xsinx
THANKS!