Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

medical science xy1110 > biochemistry 3 > Flashcards

biochemistry 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards Biology 101 flashcards
1
Q

what is gluconeogenesis

A
  • creation of new glucose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

where does gluconeogenesis occur

A
  • mainly in liver and Kinsey cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when does gluconeogenesis occur

A
  • starvation and prolonged exercise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the point of no return in carbohydrate biochemistry

A

phosphonolpyruvate —>pyruvate

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

what regulates gluconeogenesis

A
  • pyruvate carboxylase
  • phosphoenolpyruvate carboxylkinase
  • fructose-1,6-bisphosphatase
  • glucose- 6- phosphatase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

where is glucose-6-phosphate found

A

liver and ER

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

where is pyruvate carboxylase found

A

mitochondria

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

where is phosphoneolpyruvate carboxylkinase

A

cytosol

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

what are the precursors of gluconeogenesis

A
  • lactate - skeletal muscles
  • amino acids - skeletal muscles or food
  • glycerol - adipose tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

when is gluconeogenesis activated

A
  • low energy stores
  • low carbohydrate intake
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what causes a fructose-1,6-bisphosphate deficiency and what does it cause

A
  • autosmal reccesive disorder
  • mutation in FBP1
  • reduce gluconeogenesis leads to hypoglycaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does gierke disease cause - type 1- glycogen storage disease

A
  • decreased glucose-6-phosphate in liver or low endoplasmic reticulum uptake
  • increased liver glycolysis –> increased blood lactate and pyruvate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the symptoms of type 1 - glycogen disgorge disease - gierke disease

A
  • hyperglycaemia between meals
  • enlargement of liver
  • no raise in blood glucose with epinephrine and glucagon
  • increases fat metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what ethanol metabolism 1

A

Ethanol —> acetaldehyde by alcohol dehydrogenase

acetaldehyde –> acetate by aldehyde dehydrogenase

  • both produce NADH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how does increased NADH decrease gluconeogenesis

A

1) lactic acid build up
2) amino acids converted to pyruvate
3) glycerol converted to glyceraldehyde-3-phosphate
4) oxaloacetate converted to malate
- causes lactic acidosis, fatty liver, hyperglycaemia

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

how does fatty liver develop

A
  • from glyceraldehyde-3-phosphate –> lipids
17
Q

how does alcoholic hepatitis occur

A

liver cells die resulting in inflammation

18
Q

how does cirrhosis occur

A
  • scar tissue forms
  • not able to convert ammonia into urea
  • rise in blood ammonia
  • neural toxicity
19
Q

what causes alcoholic flush

A
  • dominant causing allele
  • higher protein degradation
  • acetaldehyde build up
  • overactive ADH
20
Q

what are the naturally occurring glycosidic links

A

1,2
1,4 - linear
1,6 - branched

21
Q

what is the structure importance of glycogen

A
  • glycogen spheres
  • large amount of glucose
  • short glucose chains - soluble
  • less water interacting
22
Q

glucose-6-phosphate to glucose-1-phosphate

A

phosphoglucomutase

23
Q

what converts glucose-1-phosphate to UDP-glucose

A
  • UDP glucose pyrophohorylase
  • UPT –>PPI
24
Q

what are the stages of glycogenesis

A
  • starts with glycogenin
  • transfer of glucose from UDP-glucose
  • autocatalysis - 6-7 units
  • glycogen synthase recruited and further elongation
  • branching induced by branching enzyme from 1,4 to 1,6
25
Q

what is ethanol metabolism 2

A

ethanol –> acetaldehyde by MEOS - microsomal ethanol-oxidising system

26
Q

what are the stages of glycogenolysis

A

1) glycogen phosphorylase breaks down q,4 bonds and glucose-1-phosphate released

2) debranching enzymes - 1,6 residues hydrolysed tp glucose and truncate branch to 1,4 chain

3) phosphoglucomutase - isomerism glucose-1-phosphate to glucose-6-phosphate

27
Q

what does glycogen synthase do

A
  • promotes glycogen synthesis
  • covalent modification pf insulin ang glucagon
  • glucagon signalling –> phosphorylated - inactive
  • insulin signalling –> dephosphorylated - active
28
Q

what does glycogen phosphorylase do

A
  • promotes glycogen degradation
  • allosteric control of muscle and liver - glucose, ATP and glucose-6-phosphate inhibited and AMP activated
  • covalent modification of insulin and glucagon
    glucagon - active
    insulin - inactive
29
Q

what causes type 2 glycogen storage disease (Pompe disease) and what are the symptoms

A
  • mutation of alpha 1,4 glucosidase - lysosomal enzyme
  • enlargement of the liver and proximal muscle weakness causing cardiorespiratory failure and death before 2
30
Q

what causes type 3 glycogen storage disease (cori disease ) and what are they symptoms

A
  • mutation of amyloid-1,6-glucosidase
  • hyperglycaemia, enlargement of liver, no rain in blood glucose with epinephrine and glucagon
  • increase fat metabolism
31
Q

what causes type 5 glycogen storage disease (McArdle disease) and what are the symptoms

A
  • mutation in muscle glycogen phosphorylase activity making it absent
  • increased creatine phosphate breakdown
  • short exercise causes fatigue, muscle pain and cramps

medical science xy1110 (40 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions