Explore Hormones

Which system produces chemical messengers known as hormones?

• nervous system

• immune system

• endocrine system

• cardiovascular system

These are chemical substances secreted by endocrine cells.

• lipids

• cytoplasm

• hormones

• sugars

Most hormones are ________.

• regulated by a positive feedback mechanism

• classified as steroids

• released upon stimulation by other hormones

• controlled by blood levels of ions or nutrients

Hormones are chemically categorised into which two types?

• hydrophilic

• hydrophobic

• messengers

• target cells

Which hormones bind to receptors on the plasma membrane?

• hydrophilic

• hydrophobic

• amino acids

• steroid hormones

Water-soluble hormones, such as proteins and peptide hormones, activate target cells using ________.

• direct gene activation

• the second-messenger system

• steroid hormone action

• diffusion

Which hormones cross the phospholipid membrane to reach the receptors in the nucleus of the cell?

• hydrophilic

• hydrophobic

• amino acids

• steroid hormones

How would you classify a hormone that is made from cholesterol, such as a sex hormone?

• steroid hormone

• amine hormone

• peptide hormone

• protein hormone

In the second-messenger system, what serves as the first messenger?

• cyclic AMP (cAMP)

• DNA

• ATP

• the hormone

Being lipid soluble, steroids can do all the following EXCEPT ________.

• diffuse through the plasma membranes of target cells

• catalyze a reaction that produces cyclic AMP (cAMP)

• enter the nucleus

• bind to receptor proteins within the nucleus