Q5 KIDNEY + HOMEOSTASIS

what is an enzyme

a biological catalysts

how is tertiary structure affected

The tertiary structure determines the active site which is only complementary to a specific substrate

where does hormones come from

endocrine gland

link between arterial blood pressure and renal blood flow

as arterial blood pressure increases, renal blood flows also tends to increase, delivering more blood to the kidneys

link between renal blood flow and pressure in the glomeruli

increase in renal blood flow resulted in a higher pressure in the glomeruli

nephron function

• as arterial blood pressure increases, renal blood flows also tends to increasedelivering more blood to the glomeruli.

• In response, the glomerular hydrostatic pressure also increases, which would usually raise glomerular filtration rate (GFR)

describe and explain effect of ADH to KIDNEYS

• ADH released from Posterior Pituitary Gland binds to receptors on collecting duct

• Causes aquaporins to fuse with the cell membrane

• Which makes the collecting duct more permeable to water

• So water move out of duct into blood via osmosis/ reabsorbed back into the blood in the capillaries surrounding the collecting duct

• So water potential decreases in the medulla

• Urine/Filtrate is more concentrated but less volume.

GFR AND renal artery pressure? (Renal blood flow RBF)

Describe the trend

Use you knowledge of constriction in blood afferent arteriole to explain the GFR AND THE RBF

(the graph showed an increase in both the GFR and RBF and then a slight decrease)

• Increased vasoconstriction

• Increased hydrostatic pressure

• Increased GFR?

• Due to increased resistance to flow?

What is a hormone and how is tertiary structure affected

hormone is a chemical released by the endocrine glands which binds to a specific receptor on the target tissues/ organs to produce an effect

Tertiary structure determines the shape of the hormone, shape must be complementary to the receptor. If shape of the active site of the hormone is changed then it will no longer bind to the receptors in target tissues