WorksheetsBIO3101- Carbohydrates
Total questions: 32
Worksheet time: 19mins
• carbo - carbon & hydrate - water
• contains elements: C, H, O (in a ratio of 1:2:1)
• general formula: Cn (H2O)n
• also known as saccharide or sugar
•produced primarily through photosynthesis
•functions: energy source, energy storing molecules, structural components, derivatives in molecular biology
These statements refer to
Proteins
Carbohydrates
Enzyme
Lipid
They are example of glycoconjugates except
glycolipid
proteoglycan
peptidoglycan
glycoprotein
glucose
• contains single aldehyde/ketone group & hydroxyl groups at each C: polyhydroxyaldehyde/ polyhydroxyketone
• classification:
❖chemical nature of carbonyl grp → aldehyde - aldose & ketone - ketose
❖number of their C atoms → 3Ctriose, 4C-tetrose, 5C-pentose, 6Chexose, 7C-heptose, 8C-octose
• properties: can’t be hydrolyzed, soluble in water, can form isomers
These refer to .......
oligosaccharide
disaccharide
monosaccharide
glycoproteins
• an aldohexose sugar • common names include dextrose, grape sugar, blood sugar
• most important sugar in our diet → a source of energy and metabolic intermediate for cells
• most abundant organic compound found in nature • level in blood can be as high as 0.1%
these statements refer to ....
galactose
glucose
ribose
fructose
• an aldohexose sugar
• also called brain sugar
• found in dairy products(i.e. milk) & in sugar beets
• synthesized by the body, where it forms part of glycolipids and glycoproteins in several tissues
• considered a nutritive sweetener because it has food energy
• less sweet than glucose and not very water -soluble
fructose
glucose
ribose
galactose
• an aldopentose sugar
• an important sugar used in genetic material
• not used as energy source but an important backbone of RNA
• when C2 -OH is removed, deoxyribose is formed, which is the backbone of DNA
ribose
glucose
fructose
galactose
sucrose
• a ketohexose sugar
• known also as levulose
• sweetest of all sugars
• found as sugar of the fruits and also in honey
ribose
fructose
galactose
sucrose
glucose
These picture refer to .......
oligosaccharide stereochemistry
disaccharide stereochemistry
monosaccharide stereochemistry
nonsuperimposable molecules are
contain a chiral central C (i.e. asymmetry)
are different from each other (in spatial arrangement of atoms)
are optically active
are known as enantiomers (or optical isomers)
crystalline, water soluble, sweet tasting
Optically active compounds (i.e. enantiomers) rotate the plane of the polarized light…
Levorotatory isomers rotate plane to the LEFT [L-, (-)]
Dextrorotatory isomers rotate plane to the RIGHT [D-, (+)]
Dextrorotatory isomers rotate plane to the LEFT [D-, (+)]
Levorotatory isomers rotate plane to the RIGHT [L-, (-)]
•when 2 monosaccharides are joined together to form a glycoside by a glycosidic bond
• glycosidic bond: ❖ bond bet. one anomeric C of a monosaccharide with a hydroxyl grp of another monosaccharide ❖ cat. by an enzyme glycosidase via a condensation reaction ❖ various types: (1→2); (1→3); (1→4) (1→6) & , β configurations
•crystalline, water soluble, sweet tasting
What are examples of dissacharide?
[Picture shows how glycosidic bond is formed]
sucrose
lactose
cellobiose
ribose
Glycosidic properties are
water soluble
crystalline
sweet tasting
simple
α-D-glucopyranosyl (1→2) β-Dfructofuranoside
β-D-glucopyranosyl (1→4) α-Dglucopyranose
α-D-glucopyranosyl (1→4) β-Dglucopyranose
lactose is
α-D-glucopyranosyl (1→2) β-Dfructofuranoside
β-D-galactopyranosyl (1→4) β-Dglucopyranose
•consists of between 2 - 20 monosaccharides
•can be found linked to polypeptide/lipid in glycoprotein & glycolipid
•functions:
❖ glycoprotein – immune cell recognition, improve stability of protein folding, sperm-egg interaction
❖ glycolipid - provide energy, markers for cell recognition
•2 types of glycans: ❖ N-linked – after N-glycosylation at Asn
❖ O-linked – after O-glycosylation at hydroxylysine, hydroxyproline, Ser or Thr
These statements refer to
oligosaccharide
monosaccharide
dissacharide
TEKA JOM!
What are related with polysaccharide?
store energy or as structural components
•homopolysaccharide ❖ formed from one type of monosaccharide ❖ e.g.: starch, glycogen, cellulose, chitin
heteropolysaccharide ❖ formed from 2/more types of monosaccharide ❖ e.g.: glycosaminoglycan, peptidoglycan
can be found linked to polypeptide/lipid in glycoprotein & glycolipid
•homopolysaccharide
❖ formed from one type of monosaccharide
Eg of them are;
s_____, g______n, c_______e, c_it__
(a)
heteropolysaccharide
formed from 2/more types of monosaccharide
❖ e.g.: glycosaminoglycan, peptidoglycan
formed from one type of monosaccharide
e.g.: starch, glycogen, cellulose, chitin
Starch consists of ?
❖ α-amylose – linear glucose polymer linked by α(1→4) bonds
amylopectin – glucose units are linked in a linear way with α(1→4) bonds; branching takes place with α(1→6) bonds occurring each 24 to 30 glucose units
basic structure similar to amylopectin but more branches, every 8-12 glucose residues
linear polymer of glucose – 15000 residues linked by β(1 →4) linkage
main animal food storage
more compact than starch
Which homopolysaccharide is this?
Glycogen
Cellulose
Chitin
Glycosaminoglycan
Homopolysaccharide
Instead of becoming main component of plant cell wall, cellulose also has;
1. linear polymer of glucose – 15000 residues linked by β(1 →4) linkage
2. H -bonded structure form parallel microfibril – strong & water resistant
3. ________________________
major structural importance in vertebrate animals – e.g. proteoglycan in connective tissues, skin
polymer of N-acetyl-D-glucosamine bonded by β(1→4) linkage
cross -linked with matrix containing other polysaccharides & lignin – resistant to pressure
polymers of repeating disaccharide units (i.e. Nacetylgalactosamine or N-acetylglucosamine or one of their derivatives) with either sulfate or carboxylate grps
cross-linked thru tetrapeptide side chains
main component of arthropod’s exoskeleton as well as algae/fungi cell wall
This refer to C______
chitin
cellulose
chirality
carbohydrate
chitin and cellulose are similar except .......
polymer of N-acetyl-D-glucosamine bonded by β(1→4) linkage
every C2–OH grp replaced by acetamide
3 types of microfibril: α, β, γ
Both are homopolysaccharide
Below are heteropolysaccharide except
Glacosaminoglycan
Peptidoglycan
cellulose
chitin
1. mucopolysaccharide = Glycosaminoglycan
2. major structural importance in vertebrate animals – e.g. proteoglycan in connective tissues, skin
2. polymers of repeating disaccharide units (i.e. Nacetylgalactosamine or N-acetylglucosamine or one of their derivatives) with either sulfate or carboxylate grps
3. 5 main classes: hyaluronic acid, chondroitin sulfate, dermatan sulfate, heparin/heparan sulfate & keratan sulfate
True
False
Picture shows about what?
2 of 5 main classes of glycosaminoglycan
2 of 5 main classes of peptidoglycan
2 of 5 main classes of homopolysaccharide
Which are wrong about peptidoglycan?
neighbouring parallel peptidoglycan chains are covalently cross-linked thru tetrapeptide side chains
peptide component – D-amino acid containing tetrapeptide forms amide linkage with NAM’s lactic acid residue
polymers of repeating disaccharide units (i.e. Nacetylgalactosamine or N-acetylglucosamine or one of their derivatives) with either sulfate or carboxylate grps
major structural importance in vertebrate animals – e.g. proteoglycan in connective tissues, skin
1. cross-linked complex of polysaccharides and peptides found in the cell walls of bacteria
2. gives structural strength to bacterial cell wall; protects bacteria from osmotic lysis.
osmotic lysis, occurs when a cell bursts due to an osmotic imbalance that has caused excess water to diffuse into the cell.
These statements refer to ....
starch
cellulose
gram positive
gram negative
peptidoglycan
Which picture shows gram -ve bacteria peptidoglycan framework and what is the name?
Escherichia coli
Staphylococcus aureus
Lipoprotein is available in .....
E-coli
Staphylococcus aureus
