Option: Human Phys

Is a chemical messenger that is transported indiscriminately via the bloodstream to act on a distant target cells.

Are lipophilic hormones that are able to freely diffuse across the plasma membrane of cells.

They bind to receptors in either the cytoplasm or nucleus of the target cell, for an active receptor-hormone complex. This activated complex moves into the nucleus and binds directly to DNA, acting as a transcription factor for gene expression.

They are hormones that are hydrophilic and lipophobic, thus cannot freely cross the plasma membrane.

They bind to receptors on the surface of the cell, which are typically coupled to internally anchored proteins. The receptors complex activates a series of intercellular molecules called second messengers, which initiates cell activity. This process is called signal transduction. The use of second messengers enables the amplification of the initial signals as more molecules are activated.

A section of the brain that links the nervous and endocrine systems in order to maintain homeostasis.

Is an anabolic peptide hormone that stimulates growth.

The production and secretion of milk by maternal mammary glands following birth.

Occurs when chemicals released by a cell stimulate the cell itself (self-signalling).

Occurs when chemicals released stimulate a neighbouring cell.

Occurs when chemicals released travel in the bloodstream to activate distant cells.

Hormones are released as they are produced [vesicles fuse directly with cell membrane].

Hormones are stored in vesicles and only released following an external signal.

Involves a response that is the reverse of the change detected.

Involves a response that reinforces the change detected.

A chemical substance found in foods that is used in the human body.

Nutrients that cannot be synthesised by the body and must be ingested as part of the diet.

Organic molecules with complex structures that are diverse and clasifed into groups.

Stunting Wasting Obesity

Both do not dissolve in the bloodstream and hence are carried by lipoproteins

Low density lipoproteins saturated trans fats From liver to rest of the body

High density lipoproteins cis polyunsaturated fats From body to liver

Genetic condition (autosomal) that results in impaired metabolism of phenylalanine. Caused due to mutation in gene encoding for enzyme (phenylalanine hydroxylase) that breaks excess phenylalanine into tyrosine. Normal: excess phenylalanine –> Tyrosine With PKU: Excess phenylalanine –> phenylpyruvate or phenylketone

• Stretch receptors in the stomach and intestine become activated when ingested food distends these organs • Adipose tissue releases hormones in response to fat storage • The pancreas will release hormones in response to changes in blood sugar concentrations