BMS527 4 Carbohydrates: Structure and Function Practice Flashcards

One hundred fill-in-the-blank practice flashcards covering nomenclature, stereochemistry, cyclization, and derivatives of carbohydrates as presented in the lecture.

Carbohydrates function in the storage and generation of __________ (e.g., glucose, glycogen, starch).

energy

Carbohydrates are involved in molecular recognition, such as in the __________ system.

immune

In bacterial and plant cell walls, carbohydrates provide __________ __________ .

Cellular protection

__________ is a general function of carbohydrates involving glycoproteins.

Cell adhesion

Glycosaminoglycans function as biological __________ .

lubrication

Cellulose and chitin are examples of carbohydrates used for building and maintaining __________ __________ .

biological structure

The term carbohydrate comes from the words "Carbon" + "__________".

Hydrate

A carbohydrate chain consists of a minimum of __________ carbons.

3

Carbohydrates are defined as having multiple __________ groups.

hydroxyl (-OH)

The general formula for a carbohydrate is __________ .

$$(CH_2O)_n$$

For monosaccharides, the value of $n$ in the general formula ranges from __________ .

$$3 - 9$$

Monosaccharides with aldehyde functional groups are called __________ .

Aldoses

Monosaccharides with ketone functional groups are called __________ .

Ketoses

Simple sugars and derivatives with $3$ to $9$ carbon atoms are considered __________ .

monomers

A(n) __________ is a compound formed by linking several monosaccharides together, such as a disaccharide containing $2$ units.

Oligosaccharide

A polymer formed from multiple saccharide units is called a(n) __________ .

Polysaccharide

A polysaccharide consisting of only one type of saccharide unit is a(n) __________ .

homopolysaccharide

A polysaccharide consisting of different types of saccharide units is a(n) __________ .

heteropolysaccharide

__________ is a generic term for oligosaccharides and polysaccharides.

Glycan

A monosaccharide with five carbons is categorized as a(n) __________ .

pentose

A monosaccharide with six carbons is categorized as a(n) __________ .

hexose

A(n) __________ is a monosaccharide containing both an aldehyde group and five carbons.

Aldopentose

A(n) __________ is a monosaccharide containing both a ketone group and six carbons.

Ketohexose

Small carbohydrates that can act as reducing agents toward metal salts are called __________ sugars.

Reducing

Reducing sugars can reduce metal salts such as the ionic forms __________ or __________ .

$Ag^+$ or $Cu^{2+}$

Reducing sugars possess a free OH group on the __________ carbon.

anomeric

In chemical reactions, the acronym OIL stands for __________ __________ __________ .

Oxidation is loss

In chemical reactions, the acronym RIG stands for __________ __________ __________ .

Reduction is gain

Compared to a ketone, an aldehyde contains an "extra" __________ atom, making it easy to oxidize.

H

Oxidation of an aldose converts its aldehyde group into a(n) __________ __________ .

carboxylic acid

The __________ and __________ tests utilize the oxidation of aldehydes to detect aldose sugars.

Tollen’s and Benedict’s

__________ are constitutional isomers that can readily interconvert, a process often catalyzed by enzymes.

Tautomers

__________ is a five-carbon aldose sugar shown as a linear monosaccharide.

D-Ribose

D-Glucose, D-Galactose, and D-Mannose are all examples of __________ sugars.

hexose

D-Fructose is a common example of a(n) __________ sugar.

ketone

Isomers have identical __________ formulas.

molecular

__________ isomers have the same molecular formula but a different molecular framework.

Constitutional

__________ have the same atoms bonded identically but oriented differently in space.

Stereoisomers

The second carbon of __________ carries four different substituents, making it chiral.

glyceraldehyde

__________ are optical isomers that are nonsuperimposable mirror images.

Enantiomers

Glyceraldehyde has two enantiomers designated as __________ and __________ .

D and L

To go from D- to L- glucose, every chiral carbon must "__________" or flip.

flip

The D or L configuration is determined by the position of the hydroxyl group on the __________ numbered chiral carbon.

highest

In stereochemistry, the configuration is labeled __________ if the OH group is on the left.

L

In stereochemistry, the configuration is labeled __________ if the OH group is on the right.

D

All biologically relevant carbohydrates have a(n) __________ configuration.

D-

__________ are stereoisomers that are not mirror images of each other.

Diastereomers

Pairs of diastereomers that differ at only one stereocenter are called __________ .

Epimers

L-Mannose and L-Galactose are both __________ of glucose.

diastereomers

Most monosaccharides do not exist in high quantities in the __________ form.

linear

Cyclization of monosaccharides can form five-membered rings called __________ .

furanose

Cyclization of monosaccharides can form six-membered rings called __________ .

pyranose

Ring formation creates a new asymmetric center called the __________ __________ .

anomeric center

A(n) __________ projection is the common way to represent the ring structure of carbohydrates.

Haworth

A carbohydrate is in the __________ configuration when the $CH_2OH$ and the OH on the anomeric carbon are on the same side of the ring.

beta-anomer ($\beta$)

Groups on the __________ side of a Fischer projection face upwards in a Haworth representation.

left

Groups on the __________ side of a Fischer projection face downwards in a Haworth representation.

right

Monosaccharides in water can cycle between open and ring forms, a process called __________ .

Mutarotation

Mutarotation involves a change of configuration specifically about the __________ carbon.

anomeric

The product resulting from the cyclization of a ketose sugar is a(n) __________ .

hemiketal

Cyclization of an aldose sugar results in a(n) __________ .

hemiacetal

In nucleic acids, ribose is typically used in the __________ form.

Ribofuranose

RNA specifically uses the __________ form of ribose.

$\beta$-D-Ribofuranose

The bond connecting ribose to phosphate in nucleic acids is a $5'$ __________ linkage.

phosphodiester

The bond connecting ribose to a base in nucleic acids is a $1'$ carbon __________ bond.

glycosidic

Because ring structures cannot be planar, they exist as __________ isomers.

conformational

Glucopyranose exists in two main conformations: the __________ form and the boat form.

chair

The __________ form is preferred for glucopyranose because it avoids crowding of substituents.

chair

Crowding in the boat form occurs between groups at the "__________" and "__________" positions.

bow and stern

In a chair conformation, carbon substituents can be __________ (up/down) or equatorial (out to the side).

axial

Large groups in a chair conformation prefer the __________ position to avoid steric hindrance.

equatorial

Steric hindrance between an axial group and axial hydrogens two carbons away is called a(n) __________ clash.

$1,3$-diaxial

In the open form, the aldehyde group of an aldose tautomer can be oxidized to __________ or __________ .

$COOH$ or $COO^-$

The __________ end of a sugar is the side capable of acting as a reducing agent.

reducing

Glycosidic bonds form between at least one anomeric carbon and another group, resulting in __________ carbohydrates.

Complex

An oligosaccharide contains between __________ and __________ monosaccharide units.

$$2-10$$

A polysaccharide contains more than __________ monosaccharide units.

$$10$$

The formation of a glycosidic bond is a(n) __________ reaction.

Condensation

The formation of a glycosidic bond involves the elimination of __________ .

water

Glycosidic bond formation is __________ unfavorable and usually enzyme-driven.

thermodynamically

Energy for glycosidic bond formation is often provided by coupling the reaction to __________ production.

high-energy molecule

__________ is a disaccharide consisting of two glucose units linked by an $\alpha 1,4$ glycosidic bond.

Maltose

Sucrose is composed of a glucose unit linked to fructose via a(n) __________ glycosidic bond.

$$\alpha 1, \beta 2$$

Lactose is composed of galactose linked to glucose via a(n) __________ glycosidic bond.

$$\beta 1,4$$

Starch is a storage polysaccharide that contains two components: __________ and amylopectin.

amylose

__________ is an unbranched polymer of $(\alpha(1 \rightarrow 4)\text{D-glucose})$ .

Amylose

__________ is a polymer of $(\alpha(1 \rightarrow 4)\text{D-glucose})$ with $\alpha(1 \rightarrow 6)$ branches.

Amylopectin

__________ is the storage polysaccharide in animals, which is similar to amylopectin but more frequently branched.

Glycogen

Increased __________ in glycogen leads to better solubility and more sites for enzymatic breakdown.

branching

Sugar phosphates are formed through __________ (the reaction of an alcohol with an acid).

esterification

Sugar phosphates are important intermediates in the __________ pathway.

pentose phosphate

A(n) __________ is any molecule where a sugar is bonded through its anomeric carbon to another group (usually non-carbohydrate).

Glycoside

The process of covalently attaching carbohydrate chains to proteins is called __________ .

Glycosylation

More than __________ of all eukaryotic proteins are glycoproteins.

half

__________ glycoproteins are attached to the side chain amide group of an asparagine residue.

N-linked

__________ glycoproteins are attached to the side chain hydroxyl groups of threonine or serine residues.

O-linked

Glycoproteins play roles in protein distribution, cell recognition, and cell __________ .

adhesion

ABO blood typing classifies red blood cells based on carbohydrate __________ on the cell surface.

antigens

Antigens in the ABO system are attached to membrane __________ and glycolipids.

glycoproteins

A carbohydrate with a carbonyl at the end of the chain is a(n) __________ sugar.

Aldose