生物化学词汇

生物化学词汇

Active center.

活性中心

A specialized region of an enzyme where the enzyme interacts with the substrate and catalyzes its conversion to products. Many aminoacyl residues contribute to the active center.

Adenylyl cyclase.

腺苷酸环化酶

An enzyme that catalyzes the synthetic reaction of cyclic AMP from ATP in response to hormones such as epinephrine and glucagon.

Alanine-glucose cycle.

丙氨酸-葡萄糖循环

A cooperative pathway between liver and muscle in which the ammonia and carbon from amino acid metabolism are removed from the muscle as alanine, taken up by the liver, transaminated to pyruvate, converted into glucose, and shipped out back to the muscle.

albumin.

清蛋白

Albumin makes up 50% to 55% of the proteins of plasma and is thought to be the main contributor to osmotic pressure of blood. Another important function is that albumin has very broad and non-specific binding properties.

Allosteric enzyme.

变构酶

Allosteric enzymes are enzymes whose activity at the catalytic site may be modulated by the presence of allosteric effectors at an allosteric site. Allosteric means “occupy another space”, so an allosteric effector occupy another space, giving an effect on enzymes.

Allosteric regulation.

变构调节

A type of enzyme regulation in which an effector binds to one site on the enzyme and increase or decreases the activity at another site. Allosteric regulation provides a rapid means for regulation of their activity.

Aminoacyl-tRNA synthetase.

氨基酰tRNA合成酶

The enzymes are responsible for the recognition and attachment of the 20 amino acids to specific tRNA.

Anticodon.

反密码子

The template-recognition site on tRNA is a sequence of three bases called the anticodon, which recognizes a complementary sequence of three bases on mRNA.

Apoprotein.

载脂蛋白

The protein moiety of a lipoprotein. They mediate the interaction between lipoproteins and tissues.

Apoptosis.

细胞凋亡

Programmed cell death. The programmed cell death is tightly regulated, which plays important roles in physiologic processes. Typical morphologic changes can be observed in apoptosis. One or more endonucleases degrade DNA, leading to characteristic ladder of discrete DNA fragment on electrophoresis.

Bile salts.

胆汁酸盐

Salt form of bile acids and their conjugates. Since bile contains significant quantities of sodium and potassium and the pH is alkaline, it is assumed that the bile acids and their conjugates are in a salt form, so called “bile salts.”

Biotin.

生物素

A cofactor involved in carboxylation reactions. Most enzymes that catalyze the ATP-dependent addition of CO2 to a substrate (like acetyl-CoA carboxylase) requires the cofactor biotin.

Calcitonin.

降钙素

A 32-amino-acid peptide secreted by the parathyroid. The dominant biological action of calcitonin is to mediate a lowering of serum calcium levels. The hypocalcemic and hypophosphatemic effects of calcitonin are believed to be due to an inhibition of PTH-mediated calcium resorption.

Calcium-binding protein.

钙结合蛋白

1,25(OH)2-D3 stimulates gene transcription and formation of specific mRNA that codes for “calcium-binding protein”, also called “Calbindin”. Three distinct vitamin D-induced “Calbindin” have been isolated. Two of them are found exclusively inside the intestinal and kidney cells, which are actively involved in calcium translocation.

Calmodulin.

钙调蛋白

A ubiquitous calcium sensor in eukaryotes, regulates the activities of many intracellular proteins. The binding of Ca2+ to multiple sites in calmodulin induces a major conformational change that

converts it from an inactive to an active form. Activated calmodulin binds to many enzymes and modifies their activities.

cAMP.

环化腺苷一磷酸

Second messenger for increased demand for energy and glucose. cAMP activates cAMP-dependent protein kinase. Increased cAMP levels are associated with increased protein phosphorylation. Increases in the cAMP concentration cause activation of glycogen degradation, increased fatty acid breakdown, stimulation of glycolysis in muscle, and stimulation of gluconeogenesis in the liver.

cAMP-dependent protein kinase，PKA.

依赖cAMP的蛋白激酶

Most effects of cyclic AMP in eukaryotic cells are mediated by the activation of a single protein kinase. This key enzyme is called protein kinase A or cAMP-dependent protein kinase, which alters the activities of target proteins by phosphorylating specific serine or threonine residues.

Capping.

帽子生成

Putting a 7-methylguanosine triphosphate on the 5’ end of an mRNA molecule. Capping is involved in the recognition of mRNA and may increase the stability of the RNA by preventing the attack of 5’exonucleases.

Carnitine shuttle.

肉碱穿梭

Gets fatty acyl groups into mitochondria. Fatty acyl-CoA in the cytosol is transferred to carnitine to make fatty acyl carnitine, which is transported into mitochondria. Once inside, the fatty acyl group is transferred to CoA and the carnitine is returned to the mitochondrial membrane.