Jan29 M2-Normal and Abnormal Carbohydrate Metabolism - 1 Flashcards

1
Q

3 classes of macronutrients

A

lipids, polysaccharides, proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

(EXAM) 3 stages of catabolism for macronutrients

A

1: Hydrolysis into monomers
2. conversion to acetyl coa
3. oxidative phosphorylation of acetyl coa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what ar the building blocks of lipids

A

glycerol and fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is energy in the body exactly, what do we get out of glucose

A

ATP (high energy phosphate bonds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

main source of polysaccharides in our food. which polysaccharide + all its breakdown disaccharide and monosaccharides

A

potatoes, rice, pasta: starch. maltose. glucose + glucose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what breaks down maltose into glucose + glucose

A

a disaccharase in the intestinal epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

lactose kind of molecule, food source and components

A

disaccharide. milk. glucose + galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

sucrose kind of molecule, food source and components

A

disaccharide. plant products and sugar cane. glucose + fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

basis for lactose intolerance + type of disease

A

deficiency in lactase (disaccharase). not genetic. function of bowel lost over time (mostly in early childhood). NOT genetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

symptoms in lactose intolerance + reason

A

flatulence and diarrhea. lactase not digested so goes to bowel and bacteria transform it to gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

sucrase deficiency charact.

A

rare, Inuit population, same things occur as lactase deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where glucose is the most metabolized

A

liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which monosaccharides can be transformed to glycogen (repolymerized) for storage

A

glucose and galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

GLUTs: how many and why they differ

A
  1. expressed in specific cell types bc have specific properties
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

(EXAM) two GLUTs of interest + tissues

A

glut2: liver and pancreas

glut 4: muscle and adipose tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

(EXAM) glut2 features and why useful to the liver

A

bidirectional transport bc livers metabolize glucose but also exports it when we’re fasting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

(EXAM) glut2: why useful to the pancreas

A

allows beta cell to sense circulating glucose levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

(EXAM) 3 main insulin target tissues

A

liver, fat, muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

(EXAM) glut4 in what tissue + very important property that is unique to it

A

fat and muscle.

Sensitive to insulin**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

(EXAM) how insulin acts on glut4

A

vesicles carrying glut4 but just sitting in the cell fuse with the plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

2 drivers of diabetes worldwide nowadays

A

obesity (more calories intake)

sedentarity (less calories burned)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

type 1 DM pathophgy and % of DMs

A

autoimmune destruction of insulin producing beta cells. 10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

type 2 DM pathophgy and % of DMs

A

insulin made but not as much glut4 is put in the membrane. 90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

type 2 DM: what tissue is most affected

A

skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
type 2 DM first stage (Early)
pancreas ramps up insulin prod and glucose levels stay normal
26
type 2 DM 2nd stage (later)
beta cells lose ability to produce high amount of insulin (huge amount damages the cell)
27
other disorders of macronutrients metabolism and diseases that come with these disorders
fat metab and protein metab deregulated. | stroke, kidney failure, cognitive dysfct, muscle weakness, dementia, sarcopenia, bone more prone to fracture
28
(EXAM) first enzyme of glycolysis: 2 enzymes possible
hexokinase and glucokinase
29
(EXAM) hexokinase charact and what cells
cells other than liver and pancreas. enough activity to make enough glucose for cell to survive
30
(EXAM) glucokinase charact and what cells
liver and pancreas. extra activity to break down glucose.
31
glucokinase advantages over hexokinase
more dynamic range of activity, more sensitive to glucose levels (works harder at higher glucose) and much higher max velocit
32
why glucokinase does extra activity
also responsible for making fat in the body so breaks down glucose into metabolites then used to synthesize fats which are secreted and circulate
33
(EXAM) why is the first step of glycolysis (glucose to glucose 6 P) irreversible
requires ATP consumption. REGULATED STEP
34
2nd step (glucose 6 P to fructose 6 P) what kind of rx
isomerization
35
(EXAM) 2nd step limiting enzyme in glycolysis and its job
PFK1. fructose 6 P to fructose 1-6 bisP
36
what controls PFK1 activity
hormones and metabolites in the cell
37
what happens in glycolysis after get fructose 1,6 bisP and why is it important
aldolase splits it into 2 metabolites. important bc results of downstream rxs must be multiplied by 2
38
what does aldolase yield from fructose 1,6 bisP
DHAP and glyceraldehyde 3P
39
link between DHAP and glyceraldehyde 3P + which is used for rest of glycolysis
can be converted into each other by triose phosphate isomerase. DHAP made into glyceraldehyde 3P (used for the rest of glycolysis)
40
(EXAM) why glyceraldehyde 3P to product step is important
NADH (+ H+) is made from NAD+ + Pi.
41
(EXAM)glyceraldehyde-3P + product. product name and enzyme in this rx
GAPDH. make 1,3-biphosphoglycerate
42
(EXAM) 1,3-biphosphoglycerate + product step: why important
makes ATP (gives one P to ADP)
43
(EXAM) 2nd step in glycolysis where ATP is yielded and product of this step
phsophoenoylpyruvate to pyruvate (done by pyruvate kinase). | ADP to ATP
44
(EXAM) 3 irreversible and regulated steps of glycolysis and why
1st step (GK or HK) and PFK1 step. (because consume ATP) + pyruvate kinase step (to make pyruvate)
45
(EXAM) glycolysis: investments, products and end result in terms of ATP, NADH and pyruvate
invest: 1 glucose + 2 ATP (step 1 and 3) product: 4 ATP + 2 NADH + 2 pyruvate NET: 2 ATP, 2 NADH, 2 pyruvate
46
(EXAM) insulin: fcts on muscle, fat and liver other than gluT insertion
stimulates transcription of 3 glycolysis genes: GK or HK + PFK1 + pyruvate kinase also called PK (last step)
47
GK use in pancreas vs liver
liver: provide substrate for fat synthesis pancreas: tell beta cell how much insulin to release
48
type 2 diabetes (poor response to insulin): what enzyme is affected + treatment possible
glucokinase (step 1 glycolysis. liver and pancreas). | treatment: small molecule activators of GK
49
(EXAM) one mutation in GK: disease name and treatment
MODY (maturity onset disease of the young). DON'T need insulin
50
MODY often confused with what disease and diff between the two
often confused with type 1 diabetes. type 1 DM needs insulin. MODY doesn't need insulin
51
(EXAM) 2 mutations in GK consequence and treatment
permanent neonatal DM (PNDM). Need insulin.
52
enzyme breaking down sucrose + products
sucrase. gives glucose + fructose
53
(EXAM) fructose: 2 steps diff in glycolysis and consequence
1. fructose kinase makes it fructose 1P 2. aldolase B makes it glyceraldhehyde and DHAP BYPASSES GK regulation/HK regulation
54
what can happen to glyceraldehyde from 2nd step of fructose glycolysis
1. converted to glycerol (backbone for fat synthesis( | 2. phosphorylated into glyceraldehyde-3P to use it in glycolysis
55
important theory on one of the many drivers of obesity
high consumption of fructose (ex. soft drinks) = metab rapidly by liver to make glycerol + acetylcoa to make fat
56
(EXAM) fructose intolerance cause
genetic mutation in aldolase B
57
(EXAM) 2 important implications of fructose intolerance
1. fructose 1 P is an inhibitor of PFK1 2. ATP of the cell is harvested to make fructose 1 P that won't lead to ATP prod. (phosphate and energy deficiency, liver cells damaged)
58
symptoms in fructose intolerance
toxicity, tissue damage (liver, kidney), hypoglycemia
59
(EXAM) why hypoglycemia in fructose intolerance
fructose 1 P inhibits breakdown of glycogen storage. consequence: metabolites like phosphoenoylpyruvate can't make glucose bc the more upstream pathway is blocked
60
(EXAM) glycolysis: how it is changed in cancer + name of that
hyperactivated. Warburg effect | * *cancer cell uses glucose faster and makes lactate instead of acetyl-CoA
61
(EXAM) glycolysis enzymes affected in cancer
HK overexpressed | HK and PK VARIANT is expressed (very active)
62
basis for PET scan
measure hyperactivity of glycolysis by radiolabelling glucose (add radioactive 18F on a hydroxyl group)
63
what happens to 18F glucose in the body
phosphorylated but not further metabolized and gets stocked in the cell: seen on imaging
64
PET used for what
stage cancers and check for metastases
65
what bacteria can do with pyruvate
ethanol
66
(EXAM) what our body can do with pyruvate
1. make acetyl coa to go in TCA (pyruvate dehydrogenase) 2. reduce it to lactate (lactate dehydrogenase) 3. make it oxaloacetate (pyruvate carboxylase) (OAA is TCA intermediate)
67
why transformation of pyruvate into lactate by lactate dehydrogenase is something important
needs a NADH so yields NAD. NADH is a redox metabolite exchanging protons and we need a balance of NAD and NADH in the cell bc used in a lot of places. This rx consumes the NADH produced from glycolysis
68
what determines if pyruvate made into acetyl coa or lactate
O2 amount in the cell. high O2: make acetyl coa | low O2: make lactate
69
when do we have low O2 and pyruvate made into lactate
cardioresp exercise/high intensity sport like hockey
70
why pyruvate to acetyl coa pathway works less in low O2
too much pyruvate to the few O2 left (O2 consumed too fast)
71
lactate effect on muscle + how it is metabolized
muscle pain. | lactate goes in blood, reaches lier, metab by reverse rx (lactate to pyruvate)
72
clinical use of lactate
measure in ill patients to check if severe illness bc shows something is wrong
73
high lactate can be marker of what
O2 deficiency, MI, bleeding (not delivering O2), hypotensive states.