2023/2024
12- Which hormones are essential for normal growth and development?
- Normal growth and development require growth hormone, thyroid hormone, insulin and
insulin-like growth factors.
13- Why don’t adults with growth hormone hypersecretion grow taller?
- Their epiphyseal plate have closed.
14- What does hypercalcemia do to neuronal membrane potential, and why does that effect depress
neuromuscular excitability?
- Hypercalcemia hyperpolarizes the membrane potential, which makes it harder for the neuron
to fire an action potential.
16- Describe the renal transport of Ca^2+ from the tubule lumen to the ECF as active, passive,
facilitated diffusion, and so on.
- The Na⁺-Ca2⁺ exchanger is a secondary active transporter, and the Ca2⁺-ATPase is an active
transporter.
17- Name two compounds that store energy in high-energy phosphate bonds.
- ATP and phosphocreatine store energy in high-energy phosphate bonds.
18- What are the differences between a kinase, a phosphatase, and a phosphorylase?
- A kinase transfers a phosphate group from one substrate to another. A phosphatase removes
a phosphate group, and a phosphorylase adds one.