structure and function: carbohydrates Flashcards
what are the functions of carbohydrates?
storage,structure, source of dietary fibers, major energy source, components of cellular membrane
what is the amino acid form in human?
L form
what is the sugar form in humans?
D form
what is the monomeric units of carbohydrates?
monosaccharides
what is an example of hexoses?
glucose
what can react with the free aldehyde or keto group ?
cupric ions
are aldose and ketose reducing sugars?
yes
where is the functional group located on the aldose and ketose?
aldose-carbon 1, ketose- carbon 2
detection of sugars in urine are based on what?
reducing properties of sugars
what is the unit type of sugars normally found in urine?
monosaccharides
how are aldehydes or ketones located in the sugar?
by there reducing properties
what for of carbohydrates are manly found at the urine level?
monosaccharides
after noticing the high elevation of glucose in a patients urine, the doctor concluded that the patient had, what?
diabetes mellitus
the doctor wanting to test a patient to see if they had fructose present in their blood, so he asked the nurse to get a dipstick test ready, what do you think the results will be?
you will not be able to detect sucrose with a dipstick test it is only specific for glucose
what are the sugars that can be detected by benedicts test?
glucose, sucrose, fructose
in glycolysis, there are two intermediates, glyceraldehyde and dihydroxacetoe, what type of sugars are these?
aldose and ketose
an enzyme was placed in a tube with an alpha glucose and beta glucose, which are interconvertible by mutarotation, but the enzyme only reacted with the beta glucose, why is that?
because even though they are interconvertible, the enzymes are specific to the beta form of the sugar
what are epimers?
carbohydrates that differ in the configuration around one of the asymmetric C atoms
are mannose and galactose epimers?
no because they are different in carbon atoms, mannose is C2 and C4
how are pentose sugars linked to the purine or pyrimidine base?
By Beta-N-glycosidic linkage
what are polyols?
sugar alcohols
a dipstick was used, and the doctor found that there was an elevated amount of sugar in the urine. the patient also stated that they had diabetes mellitus. which polyol is partly responsible for this disease?
sorbitol
this polyol is formed when galactose in the lens in children is untreated galactosemia?
galactitol
which disaccharide is beta1—>4?
lactose
which disaccharide is made up of glucose and fructose?
sucrose
is lactose a non reducing sugar with the beta1–>4?
no it is a reducing sugar, sucrose is non reducing
which monosaccharide is a ketohexose and contains HFCS?
fructose
is HFCS a diasaccharides or a monosacharide?
a monosaccharide
what is the linkage of sucrose?
alpha1–>2
is fructose alpha 1 —>4 ?
no it is a monosacharride
the disaccharide that cosist of 2 glucose molecule is what?
maltose
what is alpha1—>4 ?
maltose
what is the carbohydrate that is a heteropolysaccharide?
GAGS (Glycosaminoglycans)
what type of polysaccharides are starch and glycogen?
homopolysaccharides
what is glycogenin?
it is core protein surrounded by branches of glycogen and acts as a primer for glucose
where are alpha 1->6 and 1->4 located?
alpha 1->6 is located at the branches and alpha 1->4 is in the main chain
between alpha 1->6 and 1->4 ,which one is more abundant?
alpha1–>4
where do glycigen sorage disorders occur?
in the liver and muscles
where is starch present?
in plants
what are the characterisitics of amylose?
linear unbranced polymer of glucose
what is amylopectin?
branched polymer of glucose
what is the major dieatary polysaccharide?
starchand it is digested by salivary and pancreatic amylase
what isthe difference between amylopectin and glycogen?
amylopectin hase fewer number of branches compared to glycogen
what are examples of GAGs?
hyaluronic acid and heparin
whats are GAGs made up of?
glucuronic acid and an amino sugar(glucosamine or galactosamine)
how is cellulose different from starch and glycogen?
cellulose has BETA 1->4 linkage
can cellulose be cleaved by an enzyme in the human gut?
no
can lactase cleave cellulose?
no lactase can only hydrolyze the disaccharide lactose
is sucrose a non reducing sugar?
yes
is maltose a non reducing sugar?
no it is a reducing sugar
how can glycosylation occur?
O-linked(oh group-ser/thr), N-linked(Asn),
