配体(ligand)是（）。

单项选择题配体(ligand)是（）。

A．酶与底物共价结合的活性位点；
B．酶与底物非共价结合的活性位点；
C．对于一个与蛋白质以共价形式相作用的小分子的普遍称呼；
D．对于一个与蛋白质以非共价形式相作用的小分子的普遍称呼；
E．一个缺乏酶活性的球蛋白

点击查看答案

你可能感兴趣的试题

1.单项选择题肌动蛋白纤维对于黏着斑就像( )对于半桥粒。

A．肌球蛋白纤维
B．角蛋白纤维
C．微丝
D．钙粘着蛋白

点击查看答案

2.单项选择题Developing frog embryos treated with anti-fibronectin antibodies

A．Develop normally.( )
B．Stop cell division.
C．Have abnormal cell migration(迁移).
D．Don't exhibit action potentials.

点击查看答案

3.单项选择题All of the following are true about antisense RNA except ( )

A．Is complementary to mRNA.
B．Forms double-stranded RNA.
C．Joins with the 30S subunit.
D．Inhibits protein synthesis.

点击查看答案

4.单项选择题The 5S rRNA differs from the other cellular rRNAs in which of the following ways ( )

A．The genes are located outside the nucleolus(核仁).
B．The genes are transcribed by RNA polymerase III.
C．The promoter region of the 5S rRNA gene is internal to the gene.
D． all of the above

点击查看答案

5.单项选择题A eukaryotic cell has( )

A．One copy of each ribosomal transcription unit.
B．Thousands of copies of the 5S rRNA gene.
C．Two copies of each gene for rRNA and ribosomal proteins.
D．Two copies of each gene for rRNA and one copy of each ribosomal proteingene.

点击查看答案

6.单项选择题Which one of the following was used to determine the structure of the DNA molecule ( )

A．Transmission(透射) electron microscope
B．Scanning electron microscope
C．Differential centrifugatioin(差速离心)
D．X-ray crystallography

点击查看答案

7.单项选择题Plant guard cells(保卫细胞) have a higher [C1-] than the outside environment. The most likely explanation for this is( ).

A． Water leaves the cell by osmosis.
B． C1- is diffusing through transmembrane channels.
C． C1- diffusion is aided by a mobile carrier.
D．An active transport symport transports C1-/H+.
E．None of the above

点击查看答案

8.单项选择题在下列组织中, 紧密连接特别重要的有( )

A．Stomach(胃) and kidneys
B．Smooth muscle
C．Heart muscle
D．Intestinal epithelial tissue(肠表皮组织)

点击查看答案

9.单项选择题钙泵的作用主要是( )。

A．降低细胞质中Ca2+的浓度；
B．提高细胞质中Ca2+的浓度；
C．降低内质网中Ca2+的浓度；
D．降低线粒体中Ca2+的浓度

点击查看答案

10.单项选择题The hormone glucagons(胰高血糖素) stimulates the breakdown of stored glycogen in liver and muscle cells by the following enzymes. Which is the first enzyme that must be activated ( )

A．Protein kinase A
B．Phosphorylase kinase
C．Glycogen phosphorylase
D．Protein phosphatase
E． Protein phosphatase inhibitor-1

点击查看答案

延伸阅读

你可能感兴趣的试题