搜索
R1 | R2 | R3 | 抗冻活性 |
HO | CH3 | Galactosyl | No |
N-Acetyl | CH3 | Galactosyl | Yes |
N-Acetyl | H | Galactosyl | No |
N-Acetyl | CH3 | H | Yes |
O-Acetyl |
| H | No |
O-Acetyl | CH3 | Galactosyl | No |
| A．二糖与苏氨酸残基的结合不是抗冻活性所必需的 |
| B．C-3位O上连接的Galactosyl不为抗冻活性所必需 |
| C．C-2位的N-Acetyl不为抗冻活性所必需 |
| D．如果将三糖与苏氨酸残基结合其抗冻活性会升高 |
同类型试题
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
