009 Glucose Metabolism

Question 1

these two things only use glucose for energy

Answer 1

RBCs and the brain

Question 2

hypoglycemia levels

Answer 2

<60 mg/dL

Question 3

normoglycemia levels

Answer 3

70-100 mg/dL

Question 4

hyperglycemia levels

Answer 4

> 100 mg/dL

Question 5

some glucose transporters can also transport these sugars

Answer 5

fructose/ galactose

Question 6

skeletal muscle can readily take up glucose with this molecule

Answer 6

insulin

the affinity of the glucose transporter in the liver is not that high-only if concentrations are high

Question 7

GLUT 1&3

Answer 7

many different cells (continuous uptake)

Km= 1mM (high affinity for glucose)

Question 8

GLUT 2

Answer 8

pancreas and liver

Km= 15-20 mM (Serum: 4-8mM)

Question 9

GLUT 4

Answer 9

muscle and fat cells
Km= 5
Insulin metabolizes GLUT 4

Question 10

glucose can pass this barrier

Answer 10

blood brain

Question 11

fasting serum glucose for diabetes mellitus

Answer 11

> 126 mg/dL

Question 12

type 2 DiaMe transporter defect

Answer 12

GLUT 4

Question 13

diabetes insipidus

Answer 13

excessive urine excretion
deficiency of antidiuretic hormone
resulting of kidneys to reabsorb water

Question 14

three fuel molecules

Answer 14

fats
carbs/polysaccharides
proteins

Question 15

role of hexokinase or glucokinase(liver only)

Answer 15

this is the enzyme that turns glucose into glucose 6 phosphate. when this happens, the glucose is not not able to leave the cell because it is phosphorylated and has a negative charge. the only way to get out of the cell is if it becomes dephosphorylated with glucose 6 phosphatase and the liver is the only place that has this enzyme available to dephosphorylate and that is why the liver is where the glucose is stored

Question 16

caloric value of foods

Answer 16

fats have most 9.3 kcal/g
alcohol 7.0 kcal/g
carbs and proteins both 4.1 kcal/g

Question 17

anabolic reaction is

Answer 17

endergonic

Question 18

catabolic reaction is

Answer 18

exergonic

Question 19

glucose to pyruvate

Answer 19

glycolysis

Question 20

pyruvate to glucose

Answer 20

gluconeogenesis

Question 21

glucose to ribose 5-phosphate

Answer 21

pentose phosphate pathway

Question 22

glucose to glycogen

Answer 22

glycogenesis (synthesis)

Question 23

glycogen to glucose

Answer 23

glycogenolysis (degradation)

Question 24

role of glycolysis

Answer 24

leads to production of ATP which is essential to life and to other intermediates that are necessary in other pathways
catabolic
exergonic

Question 25

role of gluconeogenesis

Answer 25

anaerobic conditions in skeletal muscle lead to production of lactate from pyruvate so this pyruvate can be converted back to pyruvate for use helps control glycemia levels anabolic endergonic more reductive pathway (because most steps keep being reduced)

Question 26

role of pentose phosphate pathway

Answer 26

alternate pathway for the metabolism of glucose. backbone of needed components in the cells. reduces NADP to NADPH which has high energy electrons catabolic exergonic more oxidative pathway because reducing NADPH

Question 27

the key central molecule to everything

Answer 27

glucose 6 phosphate (it can lead to so many different pathways- glycogen, pyruvate, ribose 5 phosphate)

Question 28

where glucose to pyruvate goes to aerobic conditions

Answer 28

acetyl coA

Question 29

two ways to synthesize acetyl CoA

Answer 29

glycolysis and fatty acid beta oxidation

Question 30

glucose to pyruvate to lactate

Answer 30

anaerobic conditions

Question 31

glucose to pyruvate to acetyl CoA to Krebs

Answer 31

aerobic respiration

Question 32

does aerobic or anaerobic produce glucose faster

Answer 32

anaerobic

Question 33

what converts lactate to glucose

Answer 33

gluconeogenesis

Question 34

glucagon is made up of

Answer 34

alpha cells of the pancreas and released when serum glucose is low

Question 35

insulin is made up of

Answer 35

beta cells of the pancreas and released when serum glucose is high

Question 36

the only lipid that enter the gluconeogenic pathway

Answer 36

glycerol

Question 37

glycolysis outcomes

Answer 37

oxidation of glucose to pyruvate net synthesis of ATP anaerobic conditions (goes to lactate) aerobic conditions (oxidized to acetyl CoA, enters Krebs which then provides high energy electrons for oxphos)

Question 38

RBC lack

Answer 38

mitonchondria, can't use FA as fuel

Question 39

in brain, these can't pass the blood/brain barrier

Answer 39

FA

Question 40

in this tissue.... glycolysis produces ATP faster than FA oxidation

Answer 40

active skeletal muscle

Question 41

liver uses these as preferred fuels for overnight fasting

Answer 41

alpha keto acids and FA

Question 42

in liver, instead of using a bunch of glucose, it will be stored as

Answer 42

glycogen

Question 43

disaccharide of glucose and fructose (table sugars, fruits)

Answer 43

sucrose

Question 44

disaccharide of glucose and galactose (milk sugar)

Answer 44

lactose

Question 45

these two sugars can be converted into intermediates of the glycolytic pathway

Answer 45

fructose and galactose

Question 46

the synthesis of glucose in the liver from AA

Answer 46

gluconeogenesis

Question 47

type 1 DM effects

Answer 47

have no insulin so they have to shift from glucose as primary energy source to fatty acids which produce ketone bodies so they have to watch out for ketoacidosis

Question 48

phase 1 pentose phosphate pathway

Answer 48

oxidative reactions that lead to production of NADPH and pentose phosphates (like ribose 5 phosphate)

Question 49

phase 2 pentose phosphate pathway

Answer 49

non oxidative reactions that link to intermediates of glycolysis (ribose is converted to intermediates of the glycolytic pathway and then they can be metabolized to make ATP. all depends on the needs of the cell)

Question 50

the role of NAPDH

Answer 50

needed for the biosynthesis of FA, cholesterols and other processes in the body that require the high energy electrons

Question 51

if a cell needs NADPH but not pentoses then what happens

Answer 51

the pentoses are converted to intermediates in the glycolytic pathways

Question 52

how does the cell determine what kind of intermediates it needs from the pathways

Answer 52

depends on the concentration of ATP in the cell and depending on what the concentration is, the reaction will shift that way

Question 53

why does a deficiency of glucose 6 phosphate dehydrogenase in red blood cells fuse hemolytic anemia

Answer 53

because NADPH is needed to maintain the glutathione in a reduced state to keep a healthy RBC membrane. otherwise it will look like an old cell and the spleen will lyse the cell. may be triggered in the presence of infection that is oxidative in nature and adds stress to the cell membrane

Question 54

glycogen storage diseases

Answer 54

deficiency of glucose 6 phosphatase (GSD 1a) or glucose 6 phosphate transporter (GSD 1b) both have same effect

Question 55

GSD 1a and 1b

Answer 55

causes severe hypoglycemia, lactic acidosis, and elevated serum urate. the liver tissue is primarily affected

Question 56

is glucose a primary fuel in the liver

Answer 56

no because it is just mostly stored there as a storehouse for other tissues

Question 57

resting skeletal muscle primary fuel

Answer 57

FA

Question 58

active skeletal muscle primary fuel

Answer 58

glucose

Question 59

what two hormones have reciprocal regulation of the glycolytic pathways

Answer 59

insulin and glucagon

Question 60

phosphorylation of glycogen phosphorylase and glycogen synthase

Answer 60

activates glycogen phosphorylase | inhibits glycogen synthase

Question 61

glycogen synthase activation

Answer 61

dephosphorylation

Question 62

glycogen phosphorylase activation

Answer 62

phosphorylation