A biochemistry problem is scored no more than 100 points

Complex 3, inhibiting the oxidation of -hydroxybutyric acid or succinic acid is equivalent to completely blocking the NADH and FADH2 pathways, only blocking complex 3 and complex 4 can do it, and the formation of tetramethyl-p-phenylenediamine requires ubiquinone, non-dihydroubiquinone, so the electrons must stop at complex 3, so that vitamin C can react with tetramethyl-p-phenylenediamine.

Inhibition is succinate CoQ reductase.

There are two most important respiratory chains in the mitochondria of human cells, namely the NADH oxidizing respiratory chain and the succinic acid oxidizing respiratory chain. They differ in their initial hydrogen acceptors, the amount of ATP generated, and their applications. The NADH oxidation respiratory chain is the most widely used, and the vast majority of the dehydrogenation reactions in the catabolism of sugar, lipids and proteins are completed through this respiratory chain.

The succinic acid oxidizing respiratory chain intersects with the nadh oxidative respiratory chain pathway described above at Q. Its dehydroflavase can only catalyze the dehydrogenation of certain metabolites, but cannot catalyze the dehydrogenation of NADH or NADPH.

The transport of hydrogen and electrons in the respiratory chain has a strict sequence and direction. According to the redox principle, the redox-reduction potential E is a measure of the affinity of the substance to the electron, and the electrode potential reflects the tendency of electron gain and loss, and the lower the value of the E o', the greater the tendency of oxygen to release electrons from (A AH2), the easier it is to become a reducing agent and rank in front of the respiratory chain. Therefore, NADH has the strongest reducing ability, and oxygen molecules have the strongest oxidizing ability.

The spontaneous flow of electrons is from a substance with low electrode potential (reduced state) to an oxidation state with high potential, and it is currently accepted that it is arranged in order of increasing value according to the standard oxygen return potential.

Electrons are transferred from NADH to oxygen molecules through 3 large protein complexes, namely NADH dehydrogenase, cytochrome BC1 complex and cytochrome oxidase to oxygen (also known as complexes, electrons are transferred from FADH2 to oxygen through succinic acid-CoQ reductase (complex) through Q, complex, to oxygen (succinate-CoQ reductase catalyzes the reaction of free energy changes too little).

Oxidation of hydroxybutyric acid or succinic acid is the second respiratory chain.

Oxidation of vitamin C + tetramethyl-p-phenylenediamine is the first respiratory chain.

The two respiratory strands intersect at Q, so this inhibitor inhibits the site of the second respiratory strand before Q, which is the succinate-coenzyme Q reductase (complex).

The answer is: it is succinic acid-CoQ reductase (complex) that is inhibited

Those who are going to graduate school

Take a look at Wang Jingyan's biochemistry and there will be an answer......

How complex are creatures?

You can log in to the Creature Show**.

Solution: The number of amino acid residues shared by this protein is: 240000 120=2000 (pcs).

Let n of them be in the -fold conformation, then: 2000 - n) = where (2000-n) is the number of amino acids in the -helix = 2060 n = 981, that is, there are 981 amino acids in the -fold conformation, so the number of amino acids in the -helix is: 2000 - 981 = 1019 (pcs).

So the percentage of -helical amino acids in the total is: 1019 2000 100%=

Because random mating is large enough to satisfy the law of equilibrium of genes.

So: U+(2V 2)=U+V A:W+(2V 2)=W+V

aa: (u+v)^2 aa:(w+v)^2 aa:2*(u+v)(w+v)

2.Because the law of equilibrium is satisfied.

The proportion of the three genotypes in the second generation is not the same as the proportion of the three genotypes in the child generation.

But the gene frequency doesn't change, which means a(f2) = a(f1) a(f2) = a(f1).

aa:[(u+v)^2+(u+v)(w+v)]^2

aa:[(w+v)^2+(u+v)(w+v)]^2

aa::2*[(w+v)^2+(u+v)(w+v)]*w+v)^2+(u+v)(w+v)]

Note: [Any group of randomly mated generations can satisfy the equilibrium law, that is, the gene frequency does not change].

Random hybridization should not be calculated using Mendel's law, but directly by gamete genotype.

p0(a)=u+v, p0(a)=v+w

f1aa : aa : aa = (u+v)² u+v)(v+w) :v+w)²

The genotype of F2 can be deduced from P1(a) and P1(A).

The genotype of the second generation (F2) can be (not absolutely) the same proportion as the three genotypes of the child generation (F1), for example, when U=W, allele A and A have the same heritability, p0(a)=p0(a), so the proportion of offspring must be the same.

20 A trisaccharide is completely hydrolyzed by -galactosidase to obtain D-galactose and D-glucose, the ratio of which is 2:1, the original trisaccharide is reduced with NaBH4, and then it is completely methylated and acid-hydrolyzed, and then NaBH4 is reduced again, and finally acetic acidification with acetic anhydride to obtain two products: 2,3,4,6-tetramethyl1,5-diacetyl-galactitol liquid perturbation, trimethyl-1,5,6-triacetyl-galactitol, Pentamethyl-4-acetyl-sorbitol.

Analyze and write the structure of these three sugars. [d -galβ(1→6)d-galβ(1→4)d-glc]

When the percentage content of -d-mannose is x, then the percentage content of -d-mannose is 100-x

21x+(-92)(100-x)= x=30

Then the -D-mannose content is 30%.

Protein content = nitrogen content of the sample.

So it's grams. This happens to be written in the biochemistry book

This can't be done, first of all, you must have the name of the protein sample, and then you can find the molecular weight and n content of the protein, and you can find the protein weight by using the ratio! But now there are no protein names, so the answer is hard to find, so you can take a good look at the question!