Midterm - Carbohydrates

Question 1

stereoisomers

Answer 1

same molecular formula and sequence but differ in 3D space due to chiral carbon atoms

Question 2

enantiomer

Answer 2

mirror image

Question 3

diastereomers

Answer 3

not a mirror

Question 4

D - configuration

Answer 4

last OH group on the right

Question 5

L-configuration

Answer 5

last OH group on the left

Question 6

how to determine the number of stereoisomers for a molecule

Answer 6

2^n
where n = # chiral carbons

Question 7

why are D-monosaccharides nutritionally important

Answer 7

digestive enzymes are stereospecific for D sugars

Question 8

hemiacetal

Answer 8

made from aldose

Question 9

hemiketal

Answer 9

made from ketose

Question 10

what is the most common oligosaccharide

Answer 10

disaccharides

Question 11

what are two types of polysaccharides

Answer 11

homopolysaccharides
heteropolysaccharides

Question 12

which is more abundant in food

Answer 12

homopolysaccharides

Question 13

what polysaccharide is rich in plants

Answer 13

starch (amylose, amylopectin)

Question 14

what polysaccharide is rich in animal

Answer 14

glycogen

Question 15

what kind of fibre is cellulose

Answer 15

both a dietary and a functional fibre

Question 16

what is cellulose

Answer 16

homopolysaccharide of B-1,4 glucose units

Question 17

health benefits of fibre

Answer 17

maintains function and health of gut
decreases constipation
increases satiety

Question 18

3 fates of glucose in a cell

Answer 18

1. enters glycogenesis for energy storage
2. enters glycolysis for energy production
3. enters hexose monophosphate shunt to generate precursors for biogenesis

Question 19

what does the use of glucose depend on

Answer 19

the cell and its requirements at the time

Question 20

glycogenin

Answer 20

enzyme that serves as a scaffold on which to attach glucose molecules to build glycogen (primer)

Question 21

how many glucose molecules can be contained in a single glycogen structure

Answer 21

30,000+

Question 22

what do insulin and glucagon work to maintain

Answer 22

blood glucose homeostasis

Question 23

when does the cori cycle occur

Answer 23

anaerobic state

Question 24

what is the hexose monophosphate shunt important for

Answer 24

NADH production and ribose synthesis

Question 25

where does the hexose monophosphate shunt occur

Answer 25

cytoplasm

Question 26

what is the hexose monophosphate shunt used to generate

Answer 26

NADPH and precursors for nucleotide synthesis

Question 27

what is the total amount of energy from 1 molecule of glucose

Answer 27

38 ATP

Question 28

when is gluconeogensis active

Answer 28

when glucose is needed in the body

Question 29

what are nearly all monosaccharides taken up by

Answer 29

enterocytes

Question 30

what is the transport of glucose to galactose from lumen to blood dependent on

Answer 30

basolateral Na-K ATPase activity

Question 31

what is fructose taken up by

Answer 31

facilitated transport

Question 32

how do glucose, galactose and fructose all enter blood

Answer 32

via GLUT2

Question 33

what is the primary source of energy for cells

Answer 33

glucose

Question 34

what do carbs spare

Answer 34

protein (prevents protein breakdown)

Question 35

what do carbs prevent

Answer 35

ketosis

Question 36

what occurs when carbs are limited

Answer 36

fats get broken down for energy, producing ketone bodies and causing blood to become acidic