Nutrient digestion and absorption 1

Question 1

what are carbs needed for?

Answer 1

main energy source in the body

Question 2

Simplest carbohydrate/which one can be absorbed into the body

Answer 2

Monosaccharides

3 monosaccharides taken up by the body are glucose, galactose and fructose- hexose sugars

Question 3

What are disaccharides and main ones

Answer 3

Two monosaccharides linked together via a glycosidic bond
Lactose= glucose +galactose– broken down by lactase
Maltose= glucose+ glucose– broken down by maltase
Sucrose= fructose + glucose– broken down by sucrase

Question 4

Starch

Answer 4

• plant storage form of glucose
• L-amylose + amylopectin
• L- amylose= glucose in straight chains
• amylopectin= chained glucose with alpha 1,4 glycosidic bonds

Question 5

what can break down alpha 1,4 glycosidic bonds?

Answer 5

amylase

Question 6

Cellulose

Answer 6

• makes up plant cell walls- makes them stand
• straight chain glucose with beta 1,4 glycosidic bonds- -
• cannot be broken down by enzymes in the body
• only cellulase can break it down

Question 7

Glycogen

Answer 7

• animal storage form of glucose
• linked by alpha 1,4 glycosidic bonds
• 18 miles worth of glycogen in the body

Question 8

How is glucose taken up?

Answer 8

1- glucose and sodium taken up through apical membrane together through SGLUT1
2-inside cell sodium transported out through basolateral membrane via sodium-potassium pump
3-Glucose transported out of basolateral membrane via the GLUT-2 transporter
4- As a result of sodium being transported into the blood so is H20 through the tight juctionns

Question 9

How is galactose taken up?

Answer 9

same as glucose

Question 10

how is fructose taken up?

Answer 10

GLUT-5 in
GLUT-2 out
Does not require sodium- so no movement of h20

Question 11

How are proteins broken down?

Answer 11

peptidases and proteases

Question 12

EXO/ENDO

Answer 12

EX0= at the end-one by one
-amino
-carboxy
ENDO= in the middle

Question 13

Absorption of amino acids?

Answer 13

• aminoacid and sodium taken up by SAAT1

- h20 taken up

Question 14

Absorption of dipeptides and tripeptides

Answer 14

In acidic microclimate- Ph<6
Through PEPT1
Na taken up through NHE3

Question 15

Structure of the SI

Answer 15

• Microvilli
• Held together by adhesive junctions and tight junctions
• 2 membranes- apical and basolateral
• Digestive enzymes at brush border
• Membrane is lipid soluble so water soluble molecules need to be transported through using vectorial transport

Question 16

What are the apical and basolateral membranes in contact with?

Answer 16

Apical= the lumen 
Basolateral= blood

Question 17

Are the Membranes of the SI lipid soluble or water soluble

Answer 17

lipid