Unformatted text preview: a 1,4 linkage. the
c arbons involved are the same but linkage will make the difference - celluose hydroxyl group in the upward position. The type of linkage ( or ) determines the structure
St a r c h c an get the nutrients from grasss - organ known
as rumin - can break down the beta 1,4 glyocgic
bond. some organisms ahve the ability to
metabolism celluose - humans lack the enzyme.
metabolize stratch. E n e r g y s t o r a ge
4/15/13 C e l l u lose St r u c t u r a l su p po r t
MCB 2000 Lecture 26 have alpha 1,4 linages linear. at one branched point
y ou will have an alpha 1,6.
beyond 1,6 (branched only)
all the rest will have 1,4
linkage. amylopectin and
glyocgen only. glyocgen
adopt this structure. aniamsl
including human move a lot if an animal being chased by
pepetor. - ﬂ ight or ﬁ ght
r esponse advantage of having a branched stucture-allows for the breakdown of glyocgen at mult ends. to liberate the glucose
molecule by the animal. branched stucture allows for rapid degratio and the relaese of glucose to deal with an
emererngy situation. allows for some storage. water linked to glyocgen molecule. very polar. glyocgen Structure of Glycogen stored with water. Branched glucose
polymer linked together by
-1,4 glycosidic bonds
and -1,6 glycosidic
bonds at branch points.
Beginning of chain is
attached to a protein,
permits rapid synthesis
and degradation from
multiple reducing ends.
G- important protein that build glyocgen
s turcutre called glyocgeinin 4/15/13 Branched structure
increases solubility. Synthesis of Glycogen
When: Favored by high insulin/glucagon
ratio Synthesis occurs in response to
elevated blood glucose from a meal.
How: Requirement for UTP in the
Major enzyme: Glycogen synthase
HIgh insulin to glcagon - forming covalent bonds - Oglycolsis linkage - covalent. - make a protein from amino acids. - need to do the same
for glycogen - use UTP - use it as the activaition step - what is the activaition step for glycogen synthase? or fatty acid? or cholestoral? s ometimes use a nuecoltide- need to be aware of what the activaitoin step is. the reason you have an acitviation step is - not an exergonic
- it is engeronic -require reducing equailivant. glycogen- have a lot of enzyme for glyolcysis - glyocgen syntahse. - major enzyme r egulated - 4/15/13 MCB 2000 Lecture 26 Synthesis of Glycogen: Reactions
G-1-P + UTP
Catalyzed by UDP-glucose
pyrophosphorylase add phosphate - to trap glucose in
the cell - conecntration gradient.
c ould go into glycoysis - glyocgen
s ynthesis - start with glucose 6
phosphate - move to number 1
position - isomerization - then
gluocse 1 phosphate activate with
UTP and end up UDP glucose. this
is the activaition step glucose 1
phosphate plus UTP to get UDPglucsoe - every time you add a
s ingel glucose molecule you need
to carry out the activaiton step - not
a one time only stpe - everytime
y ou had a...
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This note was uploaded on 09/17/2013 for the course MCB 2610 / 200 taught by Professor Feldman during the Fall '12 term at UConn.
- Fall '12