Post absorptive processing of carbs

Question 1

what are the 3 sugars we get from crabs and where to they come from

Answer 1

glucose from starch and glycogen
fructose from sucrose
galactose from lactose

Question 2

same 2 diseases associated with fructose and galactose

Answer 2

hereditary fructose intolerance

galactosaemia (more rare)

Question 3

which sugar is most important in infants

Answer 3

galactose which forms 50% of carbs - comes from milk etc

Question 4

what are four possible uses for glucose

Answer 4

metab to produce energy
conversion for glycogen in store
synthesis of the cellular components (DNA)
conversion to fat for storage

Question 5

what level must blood glucose be stable at

Answer 5

5mM

below 3 = confusion and coma
above 8 = long term vascular damage

Question 6

what are the two phases of glycolysis

Answer 6

preparative phase

generating phase

Question 7

what happens in the preparative phase of glycolysis

Answer 7

glucose to fructose 1-6 biphopshate which requires ATP

Question 8

what happens during the generating phase of glycolysis

Answer 8

fructose 1-6 diphosphate to 2 pyruvate molecules which generates atp and NADH for more atp production later

Question 9

what is the difference in yield of atp in aerobic vs anaerobic conditions

Answer 9

2 in glycolysis in anaerobic
5-7 in glycolysis in aerobic
complete oxidation of glucose via kerb - 30-32

Question 10

what are the three control points of glycolysis

Answer 10

hexokinase/glucokinase
phosphofructokinase
pyruvate kinase

Question 11

describe the complete reactions of anaerobic glycolysis

Answer 11

pyruvate converted to lactate creating NAD+

NADH converted back turning glyceraldehyde phosphate to 1-3biphosphate glycerine

Question 12

what is the warburg effect and what is it used for

Answer 12

tumours take up more glucose than other tissues and using PET scan it can be used to identify tumours

Question 13

what are the two types of glycogen

Answer 13

a1-4 linkages

a1-6 branch points

Question 14

what is the difference between blood glucose and liver glycogen / muscle glycogen

Answer 14

liver glycogen fluctuates throughout the day which is why people feel ill when they don’t eat
glycogen in muscle doesn’t fluctuate like liver due to different roles
blood glucose is always stable level

Question 15

describe the steps involved in

Answer 15

conversion of glucose 6 phosphate to glucose 1 phosphate 
synthesis of UDP - glucose 
needs a primer 
chain elongation 
insertion of branch points

Question 16

in the liver and kidney what is converted to glucose

Answer 16

glucose 6 phosphate

Question 17

what are fatty acids used for

Answer 17

converted to triacylglycerols for storage

used to synthesis other lipids for membranes etc

Question 18

where does fatty acid synthesis occur

Answer 18

mainly in the liver
adipose tissue
breast tissue during lactation
in the cell cytosol

Question 19

how do you get fat on a low fat diet

Answer 19

fatty acids are synthesis from the cytosolic acetyl CoA, which is produced from citrate

Question 20

describe the process of triacylclycerol synthesis

Answer 20

addition of fatty acids to a molecule of glycerol 3 phosphate
occurs in endoplasmic reticulum

Question 21

how is triacylglyerceol stored

Answer 21

in adipose tissue - stored in cytosol
in the liver packaged into VLDL secreted into the blood where it is transport to adipose tissue and other peripheral tissues for energy

Question 22

from milliseconds to hours how long do these processes take
available substrate
amount of product
activity of enzyme - allosteric modification vs covalent modification
rate of synthesis of enzymes
degradation

Answer 22

milli 
milli 
milli 
secs-mins
hours 
hours

Question 23

what does amp activated protein kinase do

Answer 23

phosphorylates key enzymes involved in every metabolism in heart adipose tissue liver and muscle
increase energy providing pathways
inhibit anabolic pathways

Question 24

how does insulin affects glycolysis

Answer 24

increases expression of genes which code from enzymes of glycolysis
decrease those which code for glucoeogenesis
high insulin stimulates glycolysis

Question 25

how doe glucagon influence glycolysis

Answer 25

regulates level of fructose 2,6 diphosphate which ataivtes glycolysis and habits gluconeogenesis 
when phosphorylated (high glucagon) the enzymes degrades F26B which decreases glycolysis and vice versa 
high glucagon = glycolysis inhibited