Biochemical questions, masters, please come in, ask for detailed explanations

There are generally three types of high-energy phosphoric acid compounds: the phosphorus-oxygen bond type is the most common, such as phosphoenol-type compounds (PEP) and pyrophosphate compounds (ATP, AMP), but phosphorus-containing compounds are not necessarily high-energy compounds, such as glucose-6 phosphate and fructose-6 phosphate, which have very low release energy when hydrolyzed; The sulfur-carbon bond type is also a common high-energy phosphoric acid compound, such as acetyl-CoA.

The basic principle of lactose operon is to control the synthesis of three enzymes closely related to lactate metabolism (-galactosidase, galactoside permease, and -thiogalactoside transacetylase).

In the process of generating acetyl-CoA, a molecule of NADH is produced, which is oxidatively phosphorylated to produce 3 ATPs, and acetyl-CoA can produce 12 ATPs through the tricarboxylic acid cycle, so a total of 15

The raw material for the synthesis of triacylglycerol is glycerol 3-phosphate, so the conversion from glycerol to glycerol 3-phosphate requires the consumption of a high-energy phosphate bond.

RNA polymerase in prokaryotes is composed of a factor and a core enzyme whose function is to recognize the transcription start site.

A molecule of glucose anaerobic respiration can only produce 2 ATP, and the complete oxidation and decomposition of aerobic respiration can produce 38 ATP (NADH is calculated according to the production of 3 ATP, FADH2 is calculated as the production of 2 ATP, 8 ATP is produced in glycolysis, 3 are produced by pyruvate to acetyl-CoA, and 12 are produced by tricarboxylic acid, but two molecules of pyruvate are produced in glycolysis, so the ATP number of the last two processes needs to be multiplied by 2).

Because amino acids have a general formula, the difference between amino acids is only in the R group, so it depends on the side chain.

Depending on the nature of the sidechain, it can be divided into the following two categories:

1. Non-polar amino acids (7 kinds).

1. Non-polar aliphatics.

Alanine, isoleucine, leucine, valine, glycine, proline, methionine 2, non-polar aromatic.

Phenylalanine, tyrosine, tryptophan.

2. Polar amino acids.

1. Polarity is not charged.

Serine, threonine, cysteine, asparagine, glutamine 2, polar acidic (negatively charged).

Aspartic acid, glutamic acid.

3. Polar alkaline (positive charge).

Histidine, lysine, arginine.

Wrong, wrong, right.

Significance of km: KM=[S] when =vmax 2. Therefore, km is equal to the substrate concentration at half the maximum speed of the enzymatic reaction. So it has to be added.

Analysis: When the environmental pH is less than the amino acid PK, the group will undergo protonation (the carboxyl group is not dissociated and therefore uncharged; The amino group is protonated and has a positive charge). When the environmental pH is equal to the PK of a certain group of amino acids, half of the groups are dissociated (for carboxyl groups, half of the molecules are negatively charged, half of the molecules are uncharged, and each molecule has an average negative charge; For amino acids, half of the molecules are uncharged, half are positively charged, and each molecule has a positive charge on average).

When the environmental pH is greater than the PK of a certain group, the dissociation of the carboxyl group has a negative charge, and the amino group is not charged.

At pH=2, the lys-amino acid in the tetrapeptide has a positive charge and the side chain group has a positive charge. The glu-carboxyl group is negatively charged, and the side chain group is not charged; The amino and carboxyl groups of GLY and ALA are both peptide bonds and have no charged groups.

So choose A

The BAI oxidation energy supply of glutamic acid is calculated, and the ATP consumed by the removal of DU ZINH3 to synthesize urea is not considered. Glutamic acid DAO-ketoglutarate + NH3 production.

A reduced equivalent of Nadh+H+, (the enzyme in which L-glutamate dehydrogenase is present in the mitochondria, so Nadh+H+ does not need to go through the shuttle mechanism, and goes through the oxidative respiratory chain to produce an ATP) A-ketoglutarate enters the tricarboxylic acid cycle to regenerate oxaloacetate, producing a total of 2 Nadh+H+, a GTP (substrate-level phosphorylation), and a FADH2. 5+1+ oxaloacetate is decarboxylated to form pyruvate, and pyruvate is completely oxidized and decomposed to form an ATP, so a kind of generation looks at the mistakes, and asks for adoption.

The minimum number of iron atoms is 1

So, when the number of iron atoms is 1, the molecular weight is the smallest.

Just divide by 56.

When there are 4 iron atoms, multiply 4 by 56 and divide by it. Or just multiply the result by 4