Exam 2: Carbohydrates Flashcards
What are 2 other names for carbohydrates
sugars, saccharides
What are carbohydrates made of , what is the formula
C, H, O (CH2O)n
What does n mean in the formula, what is the min
n= C must be at least 3
What are the functions of carbs
energy source: glycolysis, Citric acid cycle, ETC
structural mol: cell membrane surface
signaling mol: also cell membrane surface
What are the 7 types of rxns a carb can undergo
mutarotation: changes from alpha or beta to 6 or 5 member rings
oxidation: aldehyde or CH2OC can get oxidized or both.
reduction: aldehydes and ketones are reduced to alcohols
isomerization: rearrangements
esterification: an alcohol with anything attached to it can get transferred onto the carb. PO4 and SO4 can get added.
glycoside formation: hemiacetal and alcohol create acetal. or aldehyde
glycosylation: a sugar can get attached to a protein or lipid. OH of anomeric C binds to N or O in proteins
Give examples of products of advanced and early glycosylation
early: carboxymethyllysine
advanced: pentosidine
What are the 3 monosaccharide derivatives
uronic acids: group of CH2OH is oxidized
amino sugars: replace 1+ OH with an amine or multiple amines.
deoxy sugars: removal of OH for H
What is an example of an lactone ring and why is it important
ascorbic acid vitamin C
What is an example of a product you can get from glycoside formation rxns
salicin (aspirin on steroids)
Give 2 examples of uronic acids where are they found
alpha-D-glucuronate produced in liver binds to big mols to make them more H2O sol
Beta-D-Iduronate: part of connective tissue helps with hydration
What effect comes with an amino sugar
more charged, attracts more H2O
What effect comes with an amino sugar
more charged, attracts more H2O
What is a disaccharide?
2 monosaccharides bonded together to form a glycosidic bond
What are 2 important examples of disaccharides?
lactose: in milk
beta cellobiose: degradation of cellulose in plants
sucrose: table sugar
What kind of mol is lactose
a reducing sugar with a free anomeric C
Why is lactose important in digestion
lactose = glucose + galactose. enzyme lactase breaks down lactose in intestines. If your body no longer produces lactase enzymes, you are lactose intolerant
Where is the glycosidic bond in lactose located?
between OH of C1 on galactose and C4 on glucose
What is a polysaccharide
polymer of mono or disaccharides 15-1000
What is an oligosaccharide
a mini polysaccharide with 5-15 monosaccharides
What are the 2 types of oligosaccharides
1) attached by N-link at N and Asp in protein
1) o linked: attached to protein through O in Ser or Thr
Name 4 important large polymers
starch: storage mol in plants
glycogen: storage molecule in mammals
cellulose: structural in plants
chitin: structural in exoskeletons
What is a homopolymer
polysaccharide made of 1 type of monosaccharide repeated
what is a heteropolymer
polysaccharide with 2+ different monosaccharides
Are the 4 large polymers homopolymers of heteropolymers? of what repeated molecule
homopolymers of glucose
What what is the polymer of chitin
N-acetyl glucose amine
What shape does chitin have, what kinds of bonds form
long straight chains that stack and form H bonds, per unit they form beta 1,4 glycosidic bonds
What is the polymer of cellulose
glucose beta 1,4 glucose
How are cellulose and chitin structurally different
cellulose does not have an acetyl amino group
What shape is cellulose
long strands but more rigid
Who is more rigid, cellulose or chitin, what makes them so rigid.
chitin is more. the beta 1.4 glycosidic bond allows for more H bonds in both mols
of the 4 large polymers who is the most abundant on earth
cellulose
What characteristics do both starch and glycogen have
act as glucose storage molecules
non reducing end (no anomeric C)
easier to break down than beta 1,4 linkage molecule
What are the beta 1,4 linkage molecules and what are the alpha 1,4 linkage molecules
beta: cellulose and chitin
alpha glycogen and starch
How are starch and glycogen different
starch can have kinks or branches every 20-25 monomers the bond is alpha 1,6 linkage
starch is in plants glycogen is in mammals
glycogen can have alpha 1,6 linkage every 8-12 monomers
glycogen is more compact and takes up less space
What is the polymer for starch and glycogen
alpha 1,4 glucose
What are the 2 forms of polysaccharides that can occur in starch
amylose: unbranched, alpha 1,4 linkage only (forms left handed helix)
amylopectin: branched with alpha 1,6 linkage as well as alpha 1,4 linkage
where is glycogen found in mammals? Why is the structure convenient for mammals only?
mostly in liver and muscle cells. The compact structure makes energy mobilization from hydrolysis faster. compact structure also helps to be in mobile animal bodies
What is a glycoconjugate
compounds that result from covalent linkages of carbs to both proteins and lipids
What are the 2 types of glycoconjugates describe them
proteoglycans : mostly saccharides with some proteins
glycoproteins: mostly proteins with some saccharides
What are the characteristics of proteoglycans
extremely high carb concentration
have GAG chains and N and O glycosidic linkages
produced in the golgi
Question 7.5 which of the following sugars or sugar derivatives are reducing sugars? Which are capable of mutarotation?
a) glucose
b) fructose
c) alpha methyl G glucoside
d) sucrose
a) reducing can do mutarotation
b) reducing can do mutarotation
c) non reducing
d) non reducing
What is an example of a glycoprotein that is on the surface of eukaryotic cells
CAM cell adhesion molecules.
What are the functions of glycoproteins
blood clotting factors, hormones, membrane proteins and can be enzymes
What are the roles of galactose, glucose and fructose in living organisms
glucose: primary fuel for living cells
fructose: often used as sweetening agent in food.
galactose: synthesis of biomolecules like lactose.
