Lecture 34

Question 1

which part/s of the GIT absorb nutrients ?

Answer 1

Small intestine

• carbohydrate, fat and protein
• most ions: sodium, potassium
• most water

Large intestine (colon)

• some water (fine tuning)
• some ions (fine tuning)

Question 2

How does the GIT absorb Carbohydrates?

Answer 2

Trough the enzymes

• polysaccharides (most)
• • meat and plants
• disaccharides (some)
• • sucrose
• monosaccharides (a little)
• • glucose

the carbohydrates and amino acids get diffused to the blood from the cells due to the energy source of Na+ because it goes from a high concentration ( the cells) to a low concentration (the blood) but diffusing the carbohydrate into the cells cost energy to diffuse it.

very similar to protein digestion

Question 3

How does the GIT absorb Fat?

Answer 3

they are insoluble so they don’ t mix with water.
but the biosalts that are produced in the galbladder are either hydrophobic or hydrophylic and then they break down even smaller into micelles. this absorbed into the small intestine cells. the extra salts with that gets absorbed and recycled. then in the small intestine cells they are broken down into monoglycerides and fatty acids, then reassembled into triglycerides and then that is repackaged into chylomicrons and that is reabsorbed into the blood.

Question 4

How does the GIT absorb protein?

Answer 4

• protein digestion releases amino acids

Dietary protein-> enzymatic digestion -> amino acids -> absorption -> body protein

amino acids absorbed using:
Apical (top)
- sodium- coupled secondary active transport
- the sodium electrochemical gradient is used as a driving force so it can go up the sodium gradient, and the concentration in the cell can build up and then diffuse down the sodium gradient into the blood

the protein and amino acids get diffused to the blood from the cells due to the energy source of Na+ because it goes from a high concentration ( the cells) to a low concentration (the blood) but diffusing the protein into the cells cost energy to diffuse it. water will always follow the diffusion to the blood.

Question 5

why is sodium (Na+) important for the absorption of carbohydrate and protein?

Answer 5

because its a sodium chemical gradient and is used as the channel to transport the nutrients trough (Na+/K+ ATP pump)

Question 6

where is water absorbed in the GIT and how?

Answer 6

into the blood it follows the diffusion due to osmosis

Question 7

How does exercise affect the blood supply of the GIT?

Answer 7

the blood supply increases