pentose phosphate pathway/ fructose and galactose metabolism

the pentose phosphate pathway is turned on when ...

glucose concentrations are high in the liver, or by insulin in other cells

the pentose phosphate pathway metabolizes _____ glucose molecules at once

3

pentose phosphate pathway end products

NADPH and ribose 5-phosphate

NADPH function

fat synthesis

ribose 5-phosphate function

synthesis of nucelotides, DNA, RNA, and proteins

pentose [hosphate pathway enzymes are located in the _____

cytosol

true or false: both phases of the pentose phosphate pathway must occur togethr

false

phase one of the pentose phophate pathway produces _________

6 NADPH

is phase 1 of the pentose phophate pathway reversible or nireversible?

non-reversible

is phase one of the pentose phosphate pathway oxidative or non-oxidative?

oxidative

is phase two of the pentose phophate pathway oxidative of non-oxidative?

non-oxidative

is phase two of the pentose phosphate pathway reversible or irreversible?

reversible

phase two of the pentose phophate pathway produces ...

one ribose 5-phosphate

phase two of the pentose phophate pathway is a series of ...

keto-aldo-epimer arrangements

continued part two of the pentose phophate pathway

3 ribulose 5-phosphate --> ribose 5-phosphate + 2 xylulose 5-phosphate

standalone part two of the pentose phosphate pathway

3 glucose 6-phosphate --> ribose 5-phosphate + 2 xylulose 5-phosphate

does part two of the pentose phophate pathway produces NADPH?

no

why can't rbc's make ribose 5-phosphate?

they lack ribosomes

what clinical condition is caused by NADPH deficiency/ glutathione inactivity?

hemolytic anemia

3 Glucose 6-phosphate --> 3 6-phosphogluconate enzyme

G6PD

glucuronic acid function

bonded to lipid soluble metabolites for excretion in bile and urine

lipid soluble metabolite examples

bilirubin, drugs

where does DHAP come from?

glycolysis or gluconeogenesis

When fructose is consumed by itself it is converted to _____

glucose

when fructose is consumed in large amounts with glucose, it is synthesized to ...

fatty acids

clinical outcomes of excessive fructose consumption

non-alcoholic fatty liver disease, obesity, hyperlipidemia

where does galactose and fructose catabolism occur?

in the liver

Galactose 1-phosphate + UDP Glucose ↔ glucose 1-phosphate + UDP Galactose

galactose 1-phosphate uridyl transferase

Dietary galactose + ATP ®--> galactose 1-phosphate + ADP

galactokinase

•Dietary fructose + ATP ®--> fructose 1-phosphate + ADP

fructokinase

3 Glucose 6-phosphate --> 3 6-phosphogluconate

g6pd

lactase synthesis equation

UDP galactose + glucose --> lactose

UDP galactose + glucose --> lactase

lactose synthase

where does lactose synthesis happen?

mammary gland

glucosamine 6-phosphate functions

precursor for polysaccharides

glucosamine 6-phosphate equaiton

fructose 6-phosphate + glutamine --> glucosamine 6-phosphate + glutamate

sorbitol can be formed when...

glucose of fructose levels are high

what sugar alcohol causes many of the complications in t2d?

sorbitol

what type of compound is sorbitol?

sugar alcohol

sorbbitol can be made from...

glucose and fructose

sorbitol glucose equation

glucose + nadph + h --> sorbitol + nadp

sorbitol fructose equation

fructose + nadh + h --> sorbitol + nad

glucose + nadph + h --> sorbitol + nadp

aldose reductase

aldose reductase location

blood