module 4 carbohydrates Flashcards
how is the bulk of glucose made
through photosythesis
what is the general structure for glucose; chemical
general: CnH2nOn
chemical: C6H12O6
what are the additional terms used to define carbohydrates
sugar, monosaccharide, disaccharide, polysaccaride
in general conversation what does sugar refer to
table sugar: sucrose
what is the saccharide word derived from
greek word for sugar
define monosacchardie
single sugar: mono-meaning 1
define oligosaccharides
short chain of simple sugars bonded together and similar to oligopeptides
define polysaccharides
long chain of monosaccharies: 20 or more: some are branched while others are linear
what are the 4 main functions of carbohydrates
they are an energy source
as intermediates in metabolic pathways
Structure: glucose polymers make up cellulose which is basis for corn stalk; chitin which is skeleton for bugs
RNA/DNA structure
which functional groups do monosaccharides have and what name indicates their group
either an aldehyde: aldose: deglyceralehyde
ketone: ketose: dihydroxyacetone- indicated by =O on 2nd carbon
how many carbons to monosaccharides typically have in nature
3-8 carbons
which are the smallest monosaccharides
trioses: glyceraldehyde and dihydroxyacetone
what are fisher projection formulas
2D structures that represent 3D carbohydrates
what do fisher projections show
all carbon in the molecule or indicate interior carbon by intersection of bonds
What do D and L indicate
D is right handed of molecule
L is left handed of molecule- cousin of right.
similar to human hands- same molecules but different arrangements
Where are the -OH groups on the D and L of a molecule
pentiulate: 2nd to last carbon
for D: on right hand side
for L: on left hand side
What do the D and L stand for
D: dextrorotory
L: Levororatory
why is glucose known as dextrose
because the molecule is always in the D form
Why is the molecule always in the D form in nature
specificity of enzymes that produce carbohydrates
specific active site is 3D and the one that produces glucose is in the form that outlines a D structure
define epimers
monosaccharides that differ only in 1 position
monosaccharides exist as
ring structures and straight chain structures
in a ring structure how many carbon atoms are present
5 or 6
what is a furanose ring
a ring structure that has 4 carbons and 1 oxygen atom
furanose= furan for the ring and ose indicate sugar
what is a pyranose ring
a ring structure that has 5 carbon atoms and 1 oxygen atom
define heterocyclic
a structure that has a molecule other than carbon in its structure
where does the oxygen component of the ring come from
comes from the oxygen atom that started as part of one of the alcohol groups
this group reacts with another carbon in the same molecule and forms a ring
what is a haworth projection
structural model for drawing cyclical monosaccharides
what does hemiacetal mean
molecule that forms after the oxygen from carbon 5 and carbon-1 react and form a bond
present when using glucose
where does the oxygen atom come from in terms of glucsoe
-OH group from carbon-5 react with carbon-1
electron on carbon-5 are attracted to carbon-1
they mix and a rearrangement of atoms as the -OH group on 5th carbon becomes C-O-C and the aldehyde on carbon-1 becomes an alcohol group
define anormeric carbon
reduced or reacted carbon ring structure
what is the only difference in the anormeric structures
position of the -OH group on the anormeric carbon
What are anomers
structural forms that differ only on the anormeric carbon
what are the 2 names for the anomers and where is the -OH for each of these molecules
alpha: -OH is in the down position
beta: -OH is in the up position
describe drawing galactose haworth structure
start with galactose in its fisher structure
next draw pyranose form with oxygen in upper right of the structure and CH2OH of carbon 6 in the up position
for carbon 2,3,4 put the OH in the up position if it is on the L on the fisher projection and down if its on the right
carbon 5 doesn’t have O since its involved in the hemiacetal bond
if drawing beta form put OH up and down for alpha
how can anomers convert from one to the other
through open chain molecules
what is the only structure found in polysaccharides
ring structure- no open molecules
due to the anomeric carbon that locks the structure in place
which reaction do 2 monosaccharides go through to form a glycosidic linkage and what is the new link called
condensation
o-glycosidic- highlights the oxygen in the bond
what is the most common bond for hexoses to make
how do scientists write this bond
carbon-1 of one molecule and carbon-4 of another
1->4
how is the connection shown between 2 molecules in a o-glycosidic bond
curved arrows toward oxygen atom
when is it common to see the alpha 1->6 o-glycosidic linkage
when polysaccharides whose branches form the main chain
lactose is an example of a molecule that has what and how are they joined
2 different types: glucose and galactose; joined by beta 1->4 o-glycosidic
what does an oligosaccharide of glucose molecules connected by alpha 1->4 generally create
a chain of molecules
how many monosaccharides typically make up a polysaccharide
long chain of o-glycosidic
1 thousand to 1 million
define homopolymer
single type of monosaccharide: example glucose
define heteropolymer
more than one type of monosaccharide- typically in a repeating fashion
glucose makes what 3 homopolysaccharides
starch, glycogen, cellulose
what is starch made up and which organism stores it
plants store it
made up of amylose and amylopectin
what is amylose
linear chain of glucose joined together in alpha 1->4 bonds- no breaking of the chain
what is a main chain
chain that has a few thousand to million glucose bonded together
describe amylopectin
long chain of glucose: has branches every 24-30 glucose on the main chain
branches have residues connected by alpha 1->4; allows branches to form larger compounds
what is the reducing end of a molecule
undergoes chemical reactions easily as the carbon is not connected to another monosaccharide
what is non-reducing end
left side of amylose- has o-glycosidic molecule and this limits the ability to react with other monosaccharides
what is glycogen
carbohydrate storage but in animals
long chain of glucose connected by alpha 1->4
but it does form branches alpha 1>6 every 8-12 molecules
more branching allows for more extensive storage
where is glycogen found in humans
liver and muscle
liver helps maintain glucose levels in the body
which polysaccharide is the basis for plant structures such as corn stalks and cotton
cellulose
describe cellulose structure
long chain of glucose with no branching
it is beta 1->4 instead of alpha
why can’t humans and most animals break down cellulose
we don’t have the enzyme to degrade cellulose
what does chitin form
hard skeleton of beetles and other insects
what is the structure of chitin
similar to amylose: beta 1-4 bonds
how is the chain for chitin different from cellulose
chitin has a derivitive of glucose in its chain and to each glucose molecule an a -NH–CO-CH3 has been added to carbon-2
this allows for the sheet formation in the exoskeleton
What is the H-bond
hydrogen bonds are critical and non-covalent due to the number of -OH on each glucose molecule
what is the result of many hydrogen bonds
a massive structure
typically seen in homopolysaccharides
formed from many intramolecular bonds
Which carbon in erythrose would tell you if the monosaccharide is D or L? Give the carbon’s number in your answer.
carbon 3 which is the pentilmulate carbon
Glucose and mannose are epimers. Name another epimer of glucose besides mannose.
galactose
Does the compound C7H14O8 fit the formal definition of a carbohydrate? Explain.
no. there is an additional oxygen and the general sequence should be CnH2nOn
When is the LaTeX: \alphaα 1LaTeX: \rightarrow→6 connection typically found in carbohydrates?
in polysaccharides where branching occurs
What are the similarities and differences between amylose and amylopectin? Explain in at least three complete sentences.
similarities: they are both part of starch, both are homopolysaccharides of glucose and both have alpha 1->4 connections between glucose
differences: amylopectin has branching with alpha 1->6 branches, is bigger than amylose and amylose does not have branching
How is chitin different from cellulose?
Chitin has glucose with derivitives attached. -NH-CO-CH3
where are alpha 1->6 bonds found in carbohydrates
where glycogen and amylopectin branch
In what ways are amylose and a protein alike?
they both can form alpha helices
