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69 Cards in this Set

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The 4 types of Carbohydrates are:
Monosaccharides (M-sac)
Oligosaccharide (O-sac)
Polysaccharide (P-sac)
Glycoproteins
What 3 atoms make up all carbohydrates?
Carbon

Hydrogen

Oxygen
What is the formula for an unmodified m-sacc?
(CH₂O)_n

where n >= 3

*There will be twice as many hydrogens as carbons and oxygens
Define:

M-sac
The basic carohydrate unit. Many different types.
Define:

O-sac
Polymer of M-sac with 3-10 sugar components.

** O-sacs containing three or more residues are relatively rare, occurring almost entirely in plants.
Define:

P-sac
M-sac's strung together (> 10 sugars)
Define:

Glycoproteins
Proteins with O-sac chains attached to their polypeptide side-chains
What are 6 reasons carbohydrates are important
1 - Energy from the sun captured by plants is first stores as carbohydrates.

2 - Oxidation of carbohydrates provides energy to sustain life

3 - Carbohydrates are stored as P-sac's.

4 - The building blocks for nucleotides

5 - Glycolipids are part of biological membranes

6 - They play a structural function in plants, insects and bacteria.
How do M-sacs differ from each other?
They differ in the number of carbons and the arrangement of their hydrogens and oxygens.
What 2 types of M-sacs are there?

How do you differentiate between them?
Aldose and Ketose

Aldose - Carbonyl carbon is an aldehyde

Ketose - Carbonyl carbon is a ketone
Define:

Carbonyl carbon
Carbon double bonded to an oxygen
What is the name of the smallest aldose carbohydrate?
D-glyceraldehyde
What is the name of the smallest ketose carbohydrate?
Dihydroxyacetone
In nature we rarely see M-sacs containing more than _____ carbons.
...7...
Define the physical structure of D-Glucose in terms of:

Aldose/Ketose

# of chiral centers

# of possible stereoisomers
Aldose

4 chiral centers

16 possible stereoisomers
(2^4 = 16)
What 3 important functions does D-Glucose perform?
- Energy source

- Energy storage

- Structural role in plants
How do you distinguish if a carbohydrate is in D or L configuration?
Look at the *chiral* carbon farthest away from the carbonyl group.

If the -OH is on the right, it's D configuration.

If the -OH is on the left, it's in L configuration.
In terms of drawing a carbohydrate, how do you switch between the D and L configuration?
Position of -OH and -H around every *chiral* carbon will change.

Position of -OH and -H around non-chiral centers does not matter (in terms of switching between D and L)
The D and L forms of carbohydrates are mirror images of each other, also known as _____.
...enantiomers.
Which form of M-sacs (D or L) do we mostly see in nature?
D-Monosaccharides.
Define:

Epimer
Two M-sacs differ from each other in the configuration of *one* chiral center.
What happens to M-sacs in aqueous solutions?
In aqueous solutions, M-sacs form cyclic structures with an *additional* chiral center.
What is the structural difference between:

Pyranoses and Furanoses?
Pyranoses have 6 members in their rings.

Furanoses have 5 members in their rings.
Define:

Anomeric Carbon
The carbonyl carbon in a M-sac that cyclizes. (i.e. participates in forming a ring structure)

Upon forming a ring, the anomeric carbon will either be in the "α anomer" or "β anomer" configuration.
Define:

Anomers
Stereoisomers that differ in α/β configuration.
True/False:

Different anomers have different physical properties
True.
How do you tell the difference between an "α anomer" and a "β anomer".
In the ringed structure for an α-anomer, the -OH is *opposite* the CH₂OH.

In the ringed structure for a β-anomer, the -OH is on the same side as the CH₂OH.
During cyclyzing of an M-sac, which carbon becomes the additional chiral center?
The anomeric carbon
Define:

Mutarotation
Souce: Wiki

As a cyclic M-sac in solution will spontaneously switch between it's α and β forms
Pyranoses can assume _____ conformations.
...chair...
In chair conformation, the most stable form is established by putting the bulky side chains in the _____ position.
...equatorial...
True/False:

Pyranose rings are planar.
False
Uronic acids are formed by...

What suffix is appended to their parent aldose?
...oxidizing the primary alcohol group of an aldose.

-uronic acid
Aldonic acids are formed by...

What suffix is appended to their parent aldose?
...oxidizing the aldehyde group of an aldose.

-onic acid.
Derivatives of M-sacs:

What 2 acids can be produced from oxidizing an aldose?

What can be produced through the reduction of an aldose?
Gluconic Acid or Uronic Acid are produced from oxidizing an aldose.


Alcohol sugars are produced from reducing an aldose.
Another term for "alcohol sugars" is...
...alditols.
How are Amino Sugars formed?
A hydroxyl group is replaced by an amino group.
Define:

Glycosidic bond
The covalent linkage between the anomeric carbon and an alcohol or an amine
What is an N-Glycosidic bond?

How are they formed?
Bond between an anomeric carbon and a nitrogen on an amine.

The anomeric -OH reacts with an amine.
What is an O-Glycosidic bond?

How are they formed?
Bond between the anomeric carbon and an oxygen on an alcohol.

The anomeric -OH reacts with the hydroxyl (-OH) of an alcohol.
Another term for Polysaccharides is _____.
...glycans.
What type of bond links P-sacs together?
The M-sacs that make up a P-sac are linekd together via glycosidic bonds.
The most abundant D-sac is _____.
...sucrose.
Sucrose is formed from what two M-sacs?
Glucose + Fructose
Lactose is formed from what two M-sacs?
Glucose + Galactose
How is lactose formed?
Lactose is formed by linking:

- the C₁ of Galactose in the β-configuration to...

...the C₄ of Glucose.
What type of sugar is Lactose?
Lactose is a *reducing* sugar.
Define:

Reducing sugar
Saccharides bearing anomeric carbons that have not formed glycosidic bonds.
Define:

Non-reducing sugar
Saccharides bearing anomeric carbons that have all formed glycosidic bonds.
How is sucrose formed?
Sucrose is formed by linking:

- the C₁ of Glucose in the α-configuration with...

- ...the C₂ of Fructose in the β-configuration
What type of sugar is sucrose?
A non-reducing sugar.
Define:

Starch
A mixture of glycans that plants synthesize as their principal energy reserve.
What two compounds make up starch?
α-amylose

amylopectin
What is the structure of amylose?
Amylose is a linear polymer of glucose linked through α(1-4) bonds.
What is the structure of amylopectin?
Amylopectin is a polymer made up of glucose linked through:

- α(1-4) bonds and

- α(1-6) branch points
How any carbons are on the reducing end of starch?
1

One

Uno
Where is Cellulose found?
The primary structural component of plant cell walls.
Define the structure of:

Cellulose
A linear polymer of glucose.

C₁ of one glucose in the β-configuration is linked to C₄ of another glucose.
What type of bond cross-links linear polymers of glucose together?
Hydrogen bonds!
Define:

Chitin
The principal structural component of the exoskeletons of invertebrates such as:

crustaceans, bugs, and spiders.

Also present in the cell wall of fungi and many algi.
What are 5 properties for:

Glycosaminoglycans?
• Composed of repeating units containing two sugars

• Uronic acid and a hexosamine (sulfate groups)

• Heteropolysaccharides

• Found in animals

• Fill up the extracellular spaces with a gel-like substance (linked to proteins in proteoglycans)
What is the structure of Chitin?
C₁ of N-acetylglucosamine in β-configuration is linked to the C₄ of next residue.
Proteoglycans are large complexes composed of what 2 molecules?
glycoproteins

glycosaminoglycans
Peptidoglycans are the building blocks of...
...bacterial cell walls
Peptidoglycans are formed from chains of...
...Glycosaminoglycans.
What are 3 advantages for bacteria having peptidoglycan make up their cell wall?
1) Provides rigidity

2) Shape

3) Enables bacterium to live in a hypotonic environment (without going *pop*)
Define:

Glycoproteins
Proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide side-chains.
Glycoproteins:

What amino acids function in N-linked and O-linked glycosidic bonds?
N-linked: Asparagine (Asn)

O-linked: Serine (Ser) or Threonine (Thr)
What are 3 reasons for proteins to be glycosylated?
1) Help define protein structural function

2) Protection

3) Recognition