Lecture 58

Question 1

Digestion of Proteins

Answer 1

3 stepped process (gastric digestion –> intestinal digestion of peptidases –> intestinal digestion of intracellular peptidase)
only free amino acids are released into the blood

Question 2

gastric digestion of proteins

Answer 2

low pH of the stomach denatures the proteins
first step in digestion
exception is pepsin which is stable and active in acidic pH

Question 3

intestinal digestion of proteins (2)

Answer 3

peptidase at the luminal surface produces free amino acids and di/tripeptides

Question 4

intestinal digestion of proteins (3)

Answer 4

intracellular peptidases hydrolyzes di/tripeptides

Question 5

digestion of carbohydrates

Answer 5

through a-amylase and enzymes on the luminal surface
only monosaccharides are absorbed in the body

Question 6

a-amylase

Answer 6

turns starch and glycogen to maltose and maltotriose in the saliva and pancreatic juice

Question 7

enzymes on the luminal surface of small intestine

Answer 7

maltase (converts maltose –> glucose)
sucrase (converts sucrose –> glucose/fructose)
lactase (converts lactose –> glucose/galactose)

Question 8

Raffinose

Answer 8

oligosaccharide
cannot be hydrolyzed by human enzymes

Question 9

digestion of lipids

Answer 9

solubilized first by bile acid then gastric and pancreatic lipase hydrolyzes tricylglycerols to fatty acids and monoacylglycerols

Question 10

trans fats

Answer 10

raise blood cholesterol levels and increase the risk of heart disease

Question 11

role of essential fatty acids

Answer 11

synthesize eiconsanoids

Question 12

chylomicron

Answer 12

delivers lipids to tissues

Question 13

macronutrients in muscle

Answer 13

lipids - energy source
carbohydrates –> glycogen - used during exercise
protein - storage

Question 14

macronutrients in adipose tissue

Answer 14

lipids - fat storage
excess proteins - converted to triacylglycerol
excess carbohydrates - triacylglycerol

Question 15

lipids in the brain

Answer 15

stored, but fat cannot be used as an energy source

Question 16

macronutrients in the liver

Answer 16

lipids - converted to ketone bodies in ketogenesis when starved
carbohydrates –> glycogen - used to maintain blood glucose levels

Question 17

essential fatty acids

Answer 17

omega-3 (w-3) fatty acids
omega-6 (w-6) fatty acids

Question 18

omega-3 (w-3) fatty acids

Answer 18

a-linolenic acid (18:3)
eicosapentaenoic acid (EPA)(20:5)
docosahexaenoic acid (DHA)(22:6)

Question 19

omega-6 (w-6) fatty acids

Answer 19

linoleic acid (18:2)
arachidonic acid (20:4)

Question 20

essential aa that cannot be synthesized

Answer 20

histidine
isoleucine
leucine
lysine
threonine
tryptophan
valine

Question 21

essential amino acid categories

Answer 21

cannot be synthesized in the body
not enough synthesis by the body to be sufficient

Question 22

essential aa that are not synthesized enough

Answer 22

arginine
methionine
phenylalanine

Question 23

deficiency in essential lipids

Answer 23

changes to the regulatory processes of blood pressure, blood clotting, and immune functions

Question 24

deficiency in essential proteins

Answer 24

negative nitrogen balance

Question 25

well-fed state

Answer 25

insulin release
glycolysis

Question 26

early fasting state

Answer 26

glucagon release
gluconeogenesis

Question 27

fasting state

Answer 27

gluconeogenesis
ketogenesis

Question 28

marasmus

Answer 28

inadequate intake of both protein and energy sources
thin, wasted appearance
small for their age

Question 29

Kwashiorkor

Answer 29

inadequate intake of protein with adequate energy intake
mainly in children aged 1 to 3yo
deceptive plump appearance due to edema