Chapter 6: Carbohydrates Flashcards
Recent studies on cell surface carbohydrates has demonstrated an unusually high concentration of __ (IUPAC name __) on the surface of some cancer cells. It is a complex monosaccharide that is found on all our normal cells, as well. It is a signal that a cell is “__,” thereby protecting it from attack by our immune system. If certain cancer cells have an abundance of sialic acid on the surface, those cancer cells are essentially __ to the cells of our immune system that should attack and destroy them.
- sialic acid
- N-acetylneuraminic acid
- self
- invisible
How do medical researchers aim to make cancer cells more visible to the immune system?
- Researchers attach the enzyme sialidase to an antibody that binds to cancer cells, facilitating the removal of sialic acid from the cell surface.
- The enzyme sialidase, when attached to the antibody, clips away the sialic acid from the cancer cell surface, making them identifiable as foreign by the immune system.
__ are the most abundant class of bioorganic molecules on planet Earth. Although their abundance in the human body is relatively low, they constitute about __ by mass of dry plant materials.
- Carbohydrates
- 75%
Two major types of biochemical substances
- bioinorganic substances (no carbon)
- bioorganic substances (contains carbon)
Subtypes of bioinorganic substances and their abundance in the human body
- water (70%)
- inorganic salts (about 5%)
Subtypes of bioorganic substances and their abundance in the human body
- Proteins (about 15%)
- Lipids (about 8%)
- Carbohydrates (about 2%)
- Nucleic acids (about 2%)
Green (chlorophyll-containing) plants produce __ via photosynthesis.
carbohydrates
Formula of photosynthesis
CO2 + H20 + Solar energy –(chlorophyll/plant enzymes)–> carbohydrates +O2
Two main uses for the carbohydrates in plants:
- In the form of cellulose, carbohydrates serve as structural elements
- In the form of starch, they provide energy reserves for the plants
__ is a polymer of glucose, a sugar produced by the plant during photosynthesis, and used as a source of energy. It is stored as __ in structures called __.
- Starch
- grains/granules
- amyloplasts
__ is the major carbohydrate source for humans and animals. The average human diet should ideally be about __ carbohydrate by mass.
- Dietary intake of plant materials
- two-thirds
Carbohydrates have the following functions in humans:
- Carbohydrate oxidation provides energy.
- short-term energy reserve
- supply carbon atoms for the synthesis of other biochemical substances
- genetic control of growth and development
- structural components of cell membranes.
- cell–cell and cell–molecule recognition processes.
carbohydrates that contribute to short-term energy reserve in the human body
carbohydrates stored in the form of glycogen
What is the primary function of carbohydrate oxidation in humans?
Carbohydrate oxidation provides energy, releasing approximately 4 kilocalories (kcal) of energy per gram when cells “burn” carbohydrates for fuel.
Besides energy, what do carbohydrates supply for the synthesis of other biochemical substances?
Carbohydrates supply carbon atoms necessary for the synthesis of proteins, lipids, and nucleic acids.
carbohydrates that are involved in the genetic control of growth and development of living cells
ribose and deoxyribose
carbohydrates involved in the structure of cell membranes
Carbohydrates linked to lipids
carbohydrates involved in various cell–cell and cell–molecule recognition processes.
Carbohydrates linked to proteins
the basis for the term carbohydrate (“hydrate of carbon”)
Cn(H2O)n
Most simple carbohydrates have empirical formulas that fit the general formula __ which can be written as __
- CnH2nOn
- Cn(H2O)n
A carbohydrate is a __, a __, or a compound that yields __ or __ upon hydrolysis.
- polyhydroxy aldehyde
- polyhydroxy ketone
- polyhydroxy aldehydes
- polyhydroxy ketones
Carbohydrates are classified on the basis of __
molecular size
Types of carbohydrates
- Monosaccharide
- Disaccharide
- Oligosaccharide
- Polysaccharide
- type of carbohydrate that contains a single polyhydroxy aldehyde or polyhydroxy ketone unit.
- cannot be broken down into simpler units by __.
- water-soluble, white, crystalline solids
- Monosaccharides
- hydrolysis reactions
- type of carbohydrate that contains two monosaccharide units covalently bonded to each other
- crystalline, water-soluble substances.
Disaccharides
Hydrolysis of a disaccharide produces __.
two monosaccharide units
Give 2 examples of disaccharides
- Sucrose (table sugar)
- lactose (milk sugar)
type of carbohydrate that contains 3-10 monosaccharide units covalently bonded to each other.
oligosaccharide
- seldom encountered in biochemical systems.
- usually found associated with proteins and lipids in complex molecules that have both structural and regulatory functions.
“Free” oligosaccharides
Complete hydrolysis of an oligosaccharide produces several __
monosaccharide molecules
- a __ produces 3 monosaccharide units
- a __ produces 6 monosaccharide units
- trisaccharide
- hexasaccharide
a polymeric carbohydrate that contains many monosaccharide units covalently bonded to each other. The number of monosaccharide units present in a polysaccharide varies from a few hundred units to over 50,000 units.
polysaccharide
carbohydrates that undergo hydrolysis under appropriate conditions to produce monosaccharides
- disaccharides
- oligosaccharides
- polysaccharides
The prefixes __ and __ found in the complete name of a monosaccharide are used to identify one of two possible isomeric forms called __.
- D- ; L-
- stereoisomers
By definition, each member of a pair of stereoisomers must have the same molecular formula and the same bonding pattern; D- and L- differ in the __ in the molecule.
spatial arrangements of atoms
A carbon atom that has four different groups bonded to it
chiral carbon
Any molecule containing a chiral carbon is a __ and will exist as a pair of __.
- chiral molecule
- enantiomers
images that coincide at all points when the images are laid upon each other.
Superimposable mirror images
images where not all points coincide when the images are laid upon each other.
Nonsuperimposable mirror images
Different responses are usually observed for right-handed and left-handed forms of a molecule, and our bodies typically use only _____ of the two forms of a chiral compound.
one
What are the three possible scenarios regarding the biological activity of the two forms of a chiral compound?
- Sometimes both forms are biologically active, each form giving a different response;
- Sometimes both elicit the same response, but one form’s response is many times greater than that of the other; and
- Sometimes only one of the two forms is biochemically active.
How many stereoisomeric forms can a compound with n chiral centers have, according to the general rule?
a maximum of 2^n stereoisomeric forms
When three chiral centers are present, how many stereoisomers are possible?
At most, eight stereoisomers are possible (2^3 = 8), forming four pairs of enantiomers.
isomers in which atoms have different connectivity
constitutional isomers
three types of constitutional isomers
- skeletal
- positional
- functional group isomers
isomers with different carbon atom arrangements and different hydrogen arrangements
skeletal isomer
isomers that differ in the location of the functional group
positional isomer
isomers that contain different functional groups
functional group isomers
isomers with atoms of the same connectivity that differ only in the orientation of the atoms in space
stereoisomers
types and subtypes of stereoisomers
- enantiomers
- diastereoisomers
–> cis-trans isomers
–> Most other diastereoisomers (two or more chiral centers)
- stereoisomers that are non-superimposable mirror images of each other
- Handedness (D and L forms) is determined by the configuration at the highest-numbered chiral center.
enantiomers
stereoisomerism that results from restricted rotation of chemical bonds
- sometimes possible when a ring is present
- sometimes possible when a double bond is present
cis-trans isomers
What is the characteristic feature of an optically active compound?
rotates the plane of polarized light
How does the plane-polarized light setup work?
- Begin with a sodium lamp emitting unpolarized light.
- Use a polaroid filter to create plane-polarized light.
- Shine the light through a tube with an enantiomer solution.
- Place a second polaroid filter (analyzer) after the tube.
- Rotate the second filter to observe changes in light intensity, demonstrating how enantiomers interact with plane-polarized light.
a chiral compound that rotates the plane of polarized light in a clockwise direction.
dextrorotatory compound
a chiral compound that rotates the plane of polarized light in a counterclockwise direction
levorotatory compound
Why do enantiomers share the same boiling points, melting points, and densities?
These physical properties are not influenced by chirality, as they depend on intermolecular forces, which remain identical for enantiomers.
How do enantiomers’ solubilities in achiral and chiral solvents differ?
- same solubility = achiral solvents (e.g. ethanol)
- different solubilities = chiral solvents (e.g. d-2-butanol)
What influences the rate and extent of reaction for enantiomers with another reactant?
achiral reactant = same rate and extent of reaction
chiral reactant = different rate and extent of reaction
Why do enantiomers generate different responses in the human body?
Receptor sites in the body have associated chirality. Enantiomers consistently produce varied responses when interacting with these sites, ranging from slight to very different responses.
The response of the body to the D isomer of the hormone is __ than its response to the L isomer of the hormone.
20 times greater
Classification of monosaccharides based on the type of carbonyl group
- aldose
- ketose
a monosaccharide that contains an aldehyde functional group.
aldose
aldoses are
polyhydroxy aldehydes.
a monosaccharide that contains a ketone functional group.
ketose
ketoses are
polyhydroxy ketones
How are monosaccharides typically classified?
according to:
- number of carbon atoms
- their functional group
classification for an aldose with 3 carbons
aldotriose
classification for a ketose with 6 carbons
ketohexose
Which two trioses are essential intermediates in glycolysis?
The simplest trioses:
- D-Glyceraldehyde (chiral molecule)
- dihydroxyacetone (achiral molecule)
Biochemically Important Monosaccharides
- D-Glyceraldehyde and Dihydroxyacetone (glycolysis)
- D-Glucose and D-Galactose
- D-Fructose
- D-Ribose
Biochemically Important Monosaccharide
* Found in high amounts in ripe fruits
* Blood sugar
* Also called dextrose
D-Glucose
D-Glucose is also called
dextrose
Biochemically Important Monosaccharide
* seldom encountered as a free monosaccharide
D-Galactose
Biochemically Important Monosaccharide
* Synthesized from glucose in the body for the production of lactose (a disaccharide of glucose and galactose)
D-Galactose
Biochemically Important Monosaccharide
* called brain sugar because it is a component of glycoproteins found in brain and nerve tissue
D-Galactose
Biochemically Important Monosaccharide
* also present in the chemical markers that distinguish various types of blood—A, B, AB, and O
D-Galactose
Biochemically Important Monosaccharide
* biochemically the most important
ketohexose.
D-Fructose
Biochemically Important Monosaccharide
- also known as levulose and fruit sugar
D-Fructose
D-Fructose is also known as
- levulose
- fruit sugar
Biochemically Important Monosaccharides
* sweetest-tasting of all sugars
* found in many fruits and is present in honey in equal amounts with glucose
* used as a dietary sugar because less is needed for the same amount of sweetness
D-Fructose
Biochemically Important Monosaccharide
* 5-carbon sugar (pentose)
* Component of ribonucleic acids (RNAs) and energy-rich compounds such as adenosine triphosphate (ATP).
D-Ribose
What distinguishes the structures of D-Glucose and D-Ribose?
number of carbon atoms
How do the structures of D-Fructose and D-Glucose differ?
- D-Glucose has an aldehyde functional group
- D-Fructose has a ketone functional group.
What is the structural consequence for monosaccharides with five or more carbon atoms?
they exist in equilibrium between open-chain and cyclic structures
Why are cyclic structures dominant in the equilibrium of monosaccharides?
intramolecular reaction between the carbonyl group (C=O) and a hydroxyl group (-OH), forming cyclic hemiacetals
The cyclic hemiacetal forms of D-Glucose result from the intermolecular reaction between the carbonyl group and the hydroxyl group on Carbon 5. How many enantiomers are made and what is the basis in naming them?
- 2 enantiomers
- depends on how ring closure occurs
In the cyclic hemiacetal forms of monosaccharides, what name is given when the -OH group in Carbon 5 is above? Below?
-b (beta)-
- a (alpha)-
Although monosaccharides exist mostly in cyclic forms, a small amount of the open-chain form is always present, which provides an __ – this with an adjacent hydroxyl can be oxidized to a __ by an oxidizing agent.
- aldehyde group
- carboxylic acid
aldoses act as reducing agents in such reactions, they are called __.
- reducing sugars
Primary alcohol (oxidation) –> aldehyde
Aldehyde (reduction) –> primary alcohol
Aldehyde (oxidation) –> __
- carboxylic acid
Oxidation of primary alcohol leads to
- aldehyde
Reduction of aldehyde results to
- primary alcohol
What oxidize/s the aldehyde end of an aldose to give an aldonic acid?
- Tollens and Benedict’s solutions
What does the oxidation of aldehyde end of an aldose give?
- aldonic acid
A solution when glucose reduces Ag+ ion to Ag
- Tollens Solution
A solution when glucose reduces Cu2+ ion to Cu+ ion
- Benedict’s Solution
In a Benedict’s solution, what happens when glucose is present (Positive reaction)? What will happen if there’s no presence of glucose?
- a brick-red precipitate with reducing sugars (because of Cu2O)
- Blue
Under the basic conditions associated with Tollens and Benedict’s solutions, ketoses are also__. In this situation, the ketose undergoes a __ that produces an aldose, and the aldose then reacts. Thus, all monosaccharides, both aldoses and ketoses, are__.
- reducing sugars
- structural rearrangement
- reducing sugars
__ can oxidize both ends of a monosaccharide at the same time (the carbonyl group and the terminal primary alcohol group) to produce a__. Such polyhydroxy dicarboxylic acids are known as __.
- Strong oxidizing agents
- dicarboxylic acid
- aldaric acids
Although it is difficult to do in the laboratory, in biochemical systems __ can oxidize the primary alcohol end of an aldose such as glucose, without oxidation of the aldehyde group, to produce an__.
- enzymes
- alduronic acid
The carbonyl group present in a monosaccharide (either an aldose or a ketose) can be reduced to a hydroxyl group, using __ as the reducing agent. Such polyhydroxy alcohols are called__. These alcohols are used as moisturizing agents in foods and cosmetics because of their affinity for water.
- hydrogen
- sugar alcohols or alditols
D-sorbitol have properties similar to those of the __ and also used as a sweetening agent
- trihydroxy alcohol glycerol
D-Sorbitol in our __ are metabolized by bacteria. People who are sensitive to D-Sorbitol (absorb it poorly) will have it undigested. A bacterial by-product of such bacterial action is large amounts of __, which causes major discomfort.
- large intestines
- intestinal gas
A __ is an acetal formed from a cyclic monosaccharide by replacement of the hemiacetal carbon -OH group with an -OR group. More specifically, a glycoside produced from glucose is called a glucoside, that from galactose is called a __, and so on.
- glycoside
- galactoside
__, formed from phosphoric acid and various monosaccharides, are commonly encountered in biochemical systems.
- Phosphate esters
Specific enzymes in the human body catalyze the esterification of the hemiacetal group (carbon 1) produces __
- glucose 1-phosphate
Specific enzymes in the human body catalyze the esterification of the primary alcohol group (carbon 6) in glucose to produce __
- glucose 6-phosphate
These phosphate esters of glucose are stable in aqueous solution and play important roles in the metabolism of carbohydrates. (phosphate ester formation of monosaccharides)
- glucose 1-phosphate
- glucose 6-phosphate
Amino sugars and their N-acetyl derivatives are important building blocks of polysaccharides found in __ and__. The N-acetyl derivatives of D-glucosamine and D-galactosamine are present in the __ on red blood cells, which distinguish the various__.
- chitin
- hyaluronic acid
- biochemical markers
- blood types
Derivatives of Monosaccharides
- Acidic sugars (obtained by oxidation)
- Sugar alcohols (obtained by reduction)
- Glycosides (reaction with an alcohol)
- Phosphate esters
- Amino sugars
Acidic sugar with an acid group on top
- aldonic acid (e.g. D-Gluconic acid)
Acidic sugar with an acid group on bottom
- alduronic acid (e.g. D-Glucuronic acid)
Acidic sugar with acid groups on both top and bottom
- aldaric acid (e.g. D-Glucaric acid)
Disaccharides consist of two monosaccharides joined through an “__.”
- oxygen bridge
the bond between two monosaccharides resulting from the reaction between the hemiacetal carbon atom -OH group of one monosaccharide and an -OH group on the other monosaccharide.
- glycosidic linkage
Monosaccharide (functioning as __) + monosaccharice (functioning as __) disaccharide + H2O
- hemiacetal
- alcohol
In biological systems, we commonly see only particular disaccharides, such as__, __, or__. These specific disaccharides are produced in cells because the reactions are catalyzed by enzymes.
- maltose
- lactose
- sucrose
A disaccharide that is often called malt sugar (malt=germinated barley that has been baked and ground; contains this disaccharide)
- Maltose
A disaccharide that is produced whenever the polysaccharide starch breaks down
- Maltose
A disaccharide that is made up of two D-glucose units, one of which must be α-D-glucose
- α(1→4) linkage
- Maltose
Three forms of maltose present in aqueous solution.
- α-Maltose
- β-Maltose
- Open-chain aldehyde form
In the hydrolysis of D-maltose, whether in a laboratory flask or in a living organism, it produces__. An acidic environment (H+) or the __ is needed for the hydrolysis to occur.
- two molecules of D-glucose
- enzyme maltase
__, the enzyme that breaks the glucose–glucose α(1→4) linkage present in maltose, is found both in the human body and in yeast. Consequently, maltose is __ easily by humans and is readily __ by yeast.
- Maltase
- digested
- fermented
Biochemically Important Disaccharides
It is an intermediate in the hydrolysis of the polysaccharide cellulose.
- Cellobiose
Like maltose, cellobiose contains two D-glucose monosaccharide units. Differs from maltose in that one of the d-glucose units—the one functioning as a hemiacetal—must have a __ instead of the __ * β(1→4) linkage
- β configuration
- α configuration (maltose)
Like maltose, cellobiose is a __, has __ in aqueous solution, and upon hydrolysis produces__.
- reducing sugar
- three isomeric forms
- two D-glucose molecules
Both the human body and yeast lack the enzyme __ needed to break the glucose–glucose __ of cellobiose. Thus, cellobiose cannot be digested by humans or fermented by yeast.
- cellobiase
- β(1→4) linkage
A biochemically important disaccharide that the major sugar found in milk.
- Lactose
Lactose is made up of a __ and a __ joined by a __ glycosidic linkage. The glucose hemiacetal center is unaffected when galactose bonds to glucose in the formation of lactose, so lactose is a __ (the glucose ring can open to give an aldehyde)
- β-D-galactose unit
- D-glucose unit
- β(1→4) linkage
- reducing sugar
Lactose can be hydrolyzed by __ or by the enzyme__, forming an equimolar mixture of __ and__.
- acid
- lactase
- galactose
- glucose
In the human body, the galactose so produced is then converted to __ by other enzymes.
- glucose
a condition in which people lack the enzyme lactase; lowest among Scandinavians and other northern Europeans and highest among native North Americans, Southeast Asians, Africans, and Greeks. 60% of adults (the majority) are lactose intolerant.
There are no milk-drinking adult animals; only baby animals drink milk.
- lactose intolerance
When lactose molecules remain in the intestine undigested, they __ to themselves, causing fullness, discomfort, cramping, nausea, and diarrhea.
- attract water
Bacterial fermentation of the lactose further along the intestinal tract produces __ and__, adding to the discomfort.
- acid (lactic acid)
- gas
A biochemically important disaccharide that is a common table sugar and the most abundant of all disaccharides and occurs throughout the plant kingdom.
- sucrose
A biochemically important disaccharide that has a α-D-glucose and β-F-fructose in an α,β(1→2) glycosidic linkage
- sucrose
Sucrose, unlike maltose, cellobiose, and lactose, is a __; the hemiacetal center (anomeric carbon atom) of each monosaccharide is involved in the __.
- nonreducing sugar
- glycosidic linkage
A biochemically important disaccharide exists in only one form—there are no α and β isomers, and an open-chain form is not possible.
Sucrose
Hydrolysis of sucrose formula
D-Sucrose + H2O –H+ or sucrase–> D-glucose + D-fructose (invert sugar)
When sucrose is cooked with acid-containing foods such as fruits or berries, partial hydrolysis takes place, forming some __. Jams and jellies prepared in this manner are actually sweeter than the pure sucrose
- invert sugar
artificial sweeteners and sugar substitutes
- saccharin
- aspartame
- sucralose
Honeybees and many other insects posses an enzyme called __ that hydrolyses sucrose to invert sugar. Thus, honey is predominantly a mixture of __ and __ with some unhydrolyzed __.
- invertase
- D-glucose
- D-fructose
- sucrose
The term “invert” sugar comes from the observation that the __ changes from __ (clockwise) to __ (counterclockwise) when sucrose is hydrolyzed to invert sugar.
- direction of plane-polarized light
- positive
- negative
For sucrose, the rotation is __
66+ degrees
The net rotation for invert sugar mixture of fructose? glucose?
- -93 degrees
- -+52 degrees =-40 derees
cleavage of glycosidic linkage releases the __. Water particles from the reaction by supplying an H atom to one monosaccharide (the one that retains the O atom of the glycosidic linkage) and supplying an -OH group entity to other monosaccharides
two monosaccharides
Two naturally occurring oligosaccharides found in onions, cabbage, broccoli, brussel sprouts, whole wheat, and all types of beans are the __ and the __.
- trisaccharide raffinose
- tetrasaccharide stachyose
- carbohydrates that contain three to ten monosaccharide units.
- Oligosaccharides
Humans lack the digestive enzymes necessary to metabolize either __ or __. Hence these oligosaccharides, when ingested in food, pass undigested into the large intestine, where bacteria act upon them. This bacterial action usually produces __ and __.
- raffinose
- stachyose
- discomfort
- flatulence (gas).
Many plants, including the potato plant, produce toxins as a defense against insects and predators. __ is the potato plant’s toxin. Its amounts in potatoes increase when potatoes __ and when they are __ (__).
- Solanine
- sprout
- exposed to sunlight (green coloration)
the presence of an underlying green color in the skin of potatoes denotes the presence of
chlorophyll (green pigment) and solanine (toxin)
Oligosaccharides: Blood Type
Carbohydrates present in Blood type O
- 2 Galactose
- N-acetylglucosamine
- Fructose (end)
Oligosaccharides: Blood Type
Carbohydrates present in Blood Type A
- 2 Galactose
- N-acetylglucosamine
- Fructose (end)
- N-Acetylgalactosamine (end)
Oligosaccharides: Blood Type
Carbohydrates present in Blood Type B
- 3 Galactose
- N-acetylglucosamine
- 1 Fructose (end)
What blood type is called the universal donor? universal acceptor?
- Blood Type O
- Blood Type AB
Donor Blood Type is A, what recipient blood types are compatible?
A and O
Donor Blood Type is B, what recipient blood types are compatible?
B and O
Donor Blood Type is AB, what recipient blood types are compatible?
AB
Donor Blood Type is O, what recipient blood types are compatible?
A, B, AB, O
an alternate name for a polysaccharide.
Glycan
Important parameters that distinguish various polysaccharides (or glycans) from each other are:
- The identity of the monosaccharide repeating unit(s) in the polymer chain. (homopolysaccharide and heteropolysaccharide)
- The length of the polymer chain. (from less than a hundred monomer units to over 50,000 monomer units.)
- As with disaccharides, the type of glycosidic linkage between monomer units.
- The degree of branching of the polymer chain.
a polysaccharide in which only one type of monosaccharide monomer is present.
homopolysaccharide
a polysaccharide in which more than one (usually two) type of monosaccharide monomer is present.
heteropolysaccharide
a polysaccharide that is a storage form for monosaccharides and is used as an energy source in cells.
storage polysaccharide
present in the amylopectin structure at each branch point
α (1->6) linkage
has a structure similar to that of amylopectin; all glycosidic linkages are of the a type, and both (1→4) and (1→6) linkages are present.
glycogen
__ and __ differ in the number of glucose units between branches and in the total number of glucose units present in a molecule. __ is about three times more highly branched than __, and it is much larger, with up to 1,000,000 __ units present.
- Glycogen
- amylopectin
- Glycogen
- amylopectin
- glucose
an ideal storage form for glucose. The large size of these macromolecules prevents them from diffusing out of cells.
glycogen
glucose –> glycogen
glycogenesis
glycogen –> glucose
glycogenolysis
Cellulose
Source:
Subunit:
Bonds:
Branches:
Diagram:
Shape:
- plant
- β-glucose
- 1-4
- None
- alternating monosaccharide units (upside down)
- fibrous structure (called microfibrils)
starch-amylose
Source:
Subunit:
Bonds:
Branches:
Diagram:
Shape:
- plant
- α-glucose
- 1-4
- None
- repeating units of monosaccharide
- spiral
starch-amylopectin
Source:
Subunit:
Bonds:
Branches:
Diagram:
Shape:
- plant
- α-glucose
- 1-4 and 1-6
- Yes (~per 20 subunits)
- repeating units of monosaccharides with branches
- Complexly branched and dendritic
glycogen
Source:
Subunit:
Bonds:
Branches:
Diagram:
Shape:
- animals
- α-glucose
- 1-4 and 1-6
- Yes (~per 10 subunits)
- repeating units of monosaccharides with more branches
- more Complexly branched and dendritic
the structural component of plant cell walls
cellulose
__ is the most abundant naturally occurring polysaccharide; high concentrations can be found in the __
- cellulose
- “woody” portions of plants—stems, stalks, and trunks
almost pure cellulose (95%)
cotton
percentage of cellulose in wood
50%
The linear (straight-chain) cellulose molecules, when aligned side by side, become water insoluble fibers because of __ involving the numerous __ present.
- inter-chain hydrogen bonding
- hydroxyl groups
the second most abundant naturally occurring polysaccharide.
chitin
A polysaccharide that gives rigidity to the exoskeletons of crabs, lobsters, shrimp, insects, and other arthropods, in the cell walls of fungi
chitin
Chitin is a polysaccharide that is a polymer of the amino sugar __, a monosaccharide found in blood-type oligosaccharide
N-acetyl-D-glucosamine (NAG)
types of glycosidic linkages for common glucose-containing Di- and Polysaccharides
- α (1->4) linakge
- α (1->4) and (1->6) linkages
- β (1->4) linkage
- α ,β (1–>2) linkage
2 examples of carbohydrates with α (1->4) linkage
- maltose (glucose-glucose)
- amylose (unbranched glucose polymer, form of starch)
2 examples of carbohydrates with α (1->4) and (1->6) linkages
- amylopectin (branched glucose polymer, form of starch)
- glycogen (highly branded glucose polymer)
3 examples of carbohydrates with β (1->4) linkages
- lactose (galactose-glucose)
- cellobiose (glucose-glucose)
- cellulose (unbranched glucose polymer)
An example of a carbohydrate with α,β (1–>2) linkage
sucrose (glucose-sucrose)
a polysaccharide with a disaccharide repeating unit in which one of the disaccharide components is an amino sugar and one or both disaccharide components has a negative charge due to a sulfate group or a carboxyl group.
acidic polysaccharide
An acidic polysaccharide is a polysaccharide with a disaccharide repeating unit in which one of the disaccharide components is an __ and one or both disaccharide components has a negative charge due to a __ or a __.
- amino sugar
- sulfate group
- carboxyl group
acidic polysaccharides are __; two different monosaccharides are present in an alternating pattern.
heteropolysaccharides
Two of the most well-known acidic polysaccharides are __ and __, both of which have unbranched-chain structures
- hyaluronic acid
- heparin
An acidic polysaccharide that contains alternating residues of N-acetyl-β-D-glucosamine (NAG; the monomer of chitin) and D-glucuronate.
hyaluronic acid
An acidic polysaccharide that is highly viscous; serve as lubricants in the fluid of joints
hyaluronic acid
An acidic polysaccharide associated with the jelly-like consistency of the vitreous humor of the eye.
hyaluronic acid
The Greek word __ means “glass” means hyaluronic acid solutions have a __ appearance.
- hyalos
- glass-like
a small highly sulfated polysaccharide (acidic) with only 15–90 disaccharide residues per chain.
Heparin
The monosaccharides present in heparin’s disaccharide repeating unit are a sulfate derivative of D-glucuronate (__) and a doubly sulfated derivative of d-glucosamine (__). Both of these monosaccharide derivatives contain two negatively charged acidic groups.
- D-glucuronate-2 sulfate
- N-sulfo-D-glucosamine-6-sulfate
Heparin is a __. It is naturally present in mast cells and is released at the site of tissue injury. ◀ It prevents the formation of clots in the blood and retards the growth of existing clots within the blood. It does not, however, break down clots that have already formed.
- blood anticoagulant
Pharmaceutical-grade heparin is applied as an anticoagulant to the interior/exterior surface of external objects that come in contact with blood (test tubes, kidney dialysis machine surfaces, prosthetic implant materials) to prevent the blood from __. The source for pharmaceutical heparin is the __ or __ of slaughterhouse animals (pigs and cows).
- clotting
- intestinal
- lung tissue
a dietary monosaccharide or dietary disaccharide; are usually sweet to the taste and are commonly referred to as sugars
simple carbohydrates
two types of simple carbohydrates
- natural sugar
- refined sugar
a type of simple carbohydrate that is naturally present in whole foods. Give 2 important sources
natural sugar
- milk
- fresh fruit
a type of simple carbohydrate that has been separated from its plant source. Give 2 major sources
refined sugar
- sugar beets
- sugar cane
A type of simple carbohydrate is often said to provide empty calories because it provides energy but few other nutrients.
refined sugar
a type of simple carbohydrate that is accompanied by nutrients.
natural sugar
A tablespoon of sucrose (table sugar, refined) provides __ of energy just as a small orange does. The small orange (natural sugar), however, also supplies __, __, __, and __; table sugar provides no other nutrients.
- 50 calories
- vitamin C
- potassium
- calcium
- fiber
a dietary polysaccharide.
complex carbohydrate
The main complex carbohydrates are __ and __, substances not generally sweet to the taste.
- starch
- cellulose
It is now known that mono-, di-, and oligosaccharides attached through glycosidic linkages to lipid molecules (__) and protein molecules (__) have a wide range of biochemical functions, including allowing cells to interact with invading bacteria and viruses and enabling cells of differing function to recognize each other.
- glycolipids
- glycoproteins
a lipid molecule that has one or more carbohydrate (or carbohydrate derivative) units covalently bonded to it.
glycolipid
a protein molecule that has one or more carbohydrate (or carbohydrate derivative) units covalently bonded to it.
glycoprotein
Glycolipids called __ and __ occur extensively in brain tissue
- cerebrosides
- gangliosides
Glycoproteins called __ are key components of the body’s immune system response to invading foreign materials
immunoglobins
5 types of antibodies
- IgA
- IgD
- IgE
- IgG
- IgM
Y-shaped proteins that recognize unique markers (antigens) on pathogens
antibodies or immunoglobulins (Ig)
type of antibody:
- secreted into mucous, saliva, tears, and colostrum.
- Tags pathogens for destruction
IgA
type of antibody:
- a B-cell receptor
- Stimulates release of IgM
IgD
type of antibody:
- binds mast cells and basophils
- Allergy and antiparasitic activity
IgE
type of antibody:
- bonds to phagocytes
- Main blood antibody for secondary responses.
- Crosses placenta
IgG
type of antibody:
- fixes complement. - maintain antibody of primary responses
- B-cell receptor
- Immune system memory
IgM
