IPS1- Metabolic Pathway Concepts p2

Proverbs 16:3

R–CO–R → R₂CHOH

How are polyhydric alcohols formed from ketones?
A. R–CO–R → R₂CHOH
B. R–CO–R → R–CH₂OH
C. R–CO–R → R–COOH
D. R–CO–R → R–O–R

Monosaccharides

[CARBOHYRDATE CLASSIFICATION]

They are synthesized by reduction of the monosaccharides for use in the manufacture of foods for weight reduction and for diabetics

Monosaccharides

[CARBOHYRDATE CLASSIFICATION]

They are poorly absorbed and they have about half the energy yield of sugars.

B. They are poorly absorbed and yield about half the energy of sugars

Why are sugar alcohols used in foods for diabetics and weight reduction?
A. They are sweeter than glucose
B. They are poorly absorbed and yield about half the energy of sugars
C. They provide more calories than sugars
D. They cannot be metabolized

Disaccharides

[CARBOHYRDATE CLASSIFICATION]

These are condensation products of two monosaccharide units

Glucose + galactose

What two sugars make up lactose?

A. Glucose + fructose

B. Glucose + galactose

C. Glucose + glucose

D. Fructose + galactose

Glucose + glucose, α(1→4)

What two sugars make up maltose, and what bond connects them?

A. Glucose + fructose, α(1→4)

B. Glucose + glucose, α(1→4)

C. Glucose + glucose, α(1→6)

D. Glucose + galactose, β(1→4)

Glucose + glucose, α(1→6)

What two sugars make up isomaltose, and what bond connects them?
A. Glucose + glucose, α(1→6)
B. Glucose + glucose, α(1→4)
C. Glucose + fructose, α(1→2)
D. Glucose + galactose, β(1→4)

Glucose + fructose

What two sugars make up sucrose?
A. Glucose + galactose
B. Glucose + glucose
C. Glucose + fructose
D. Fructose + galactose

Glucose + glucose, α(1→1)

What two sugars make up trehalose, and what bond connects them?
A. Glucose + glucose, α(1→1)
B. Glucose + glucose, α(1→4)
C. Glucose + fructose, α(1→2)
D. Glucose + galactose, β(1→4)

Oligosaccharides

[CARBOHYRDATE CLASSIFICATION]

Condensation products of 3–10 monosaccharides

No, most are not digested

Are most oligosaccharides digested by human enzymes?
A. Yes, completely
B. No, most are not digested
C. Only in infants
D. Only when combined with proteins

Carbohydrates

_____- are aldehyde or ketone derivatives of polyhydric alcohols.

Polysaccharides

[CARBOHYRDATE CLASSIFICATION]

Are made by linking more than ten sugar units (monosaccharides) together.

• starches

• dextrins

Example of Polysaccharide

Either straight (linear) or branched

Polysaccharides can be:
A. Only linear
B. Only branched
C. Either linear or branched
D. Neither

Polysaccharides made of 6-carbon sugars

What are hexosans?
A. Polysaccharides made of 5-carbon sugars
B. Polysaccharides made of 6-carbon sugars
C. Monosaccharides with six carbons
D. Polysaccharides with mixed sugars

Polysaccharides made of 5-carbon sugars

What are pentosans?
A. Polysaccharides made of 5-carbon sugars
B. Polysaccharides made of 6-carbon sugars
C. Disaccharides with pentoses
D. Fiber polysaccharides

six-carbon sugars

starches and dextrins are made of ____ carbon sugar

True

[T/F] Foods also have many nonstarch polysaccharides

Nonstarch polysaccharides

Which polysaccharides are indigestible by human enzymes and make up most dietary fiber?
A. Starches
B. Dextrins
C. Nonstarch polysaccharides
D. Maltose

• Cellulose

• Inulin 

Example of Nonstarch polysaccharides [2]

Cellulose 

[NON STARCH POLYSACCHARIDE]

____ - from plant cell walls, made of glucose

Inulin

[NON STARCH POLYSACCHARIDE]

____ - a storage carbohydrate in some plants, made of fructose

Fructose

What is inulin made of?
A. Glucose
B. Fructose
C. Galactose
D. Ribose

Glucose

What is cellulose made of?
A. Glucose
B. Fructose
C. Galactose
D. Ribose

Glucose

Biomedically, which monosaccharide is the most important?
A. Galactose
B. Ribose
C. Glucose
D. Fructose

• The straight-chain form shows glucose as a simple open chain (called an aldohexose).

• But glucose mostly forms a ring (cyclic) structure by the aldehyde group reacting with a hydroxyl group.

• This ring form is more stable and it explains many of glucose’s properties.

Glucose has three ways to show its structure such as ____

Aldohexose

Glucose is chemically classified as what type of sugar?
A. Aldohexose
B. Ketohexose
C. Pentose
D. Aldopentose

Straight-chain form

Which structural form of glucose shows it as a simple open chain?
A. Cyclic form
B. Straight-chain form
C. Disaccharide form
D. Branched form

The aldehyde group reacts with a hydroxyl group

What causes glucose to form a cyclic (ring) structure?
A. Oxidation of glucose
B. The aldehyde group reacts with a hydroxyl group
C. Polymerization
D. Loss of a hydrogen atom

Ring (cyclic) form

Which form of glucose is more stable and explains many of its properties?
A. Open-chain form
B. Ring (cyclic) form
C. Ketone form
D. Oxidized form

Haworth projection

The cyclic structure of glucose is usually shown using the ______

A. Fischer projection
B. Haworth projection
C. Newman projection
D. Chair projection

From the side and above the ring

In the Haworth projection of glucose, how is the molecule viewed?
A. From below only
B. From the side and above the ring
C. From directly overhead
D. From the edge

Bold and thick

In a Haworth projection, how are bonds closest to the viewer drawn?
A. Thin and dashed
B. Dotted
C. Bold and thick
D. Wavy lines

Their orientation above or below the ring

In the Haworth projection, what do the positions of hydroxyl (–OH) groups indicate?
A. Their color
B. Their orientation above or below the ring
C. Their molecular weight
D. Their electronegativity

They are implied and simplify the structure

Why are hydrogen atoms often omitted in Haworth projections of glucose?
A. They are implied and simplify the structure
C. They are not part of the ring
D. They are unstable

Chair-like conformation

In reality, the ring shape is more like a _____
A. Flat hexagon
B. Chair-like conformation
C. Boat conformation
D. Straight chain

Note the 2nd to the last carbon If OH is in Left (levorotatory) Right (Dextrorolatory)

D- and L-isomerism of glycerose and glucose.

Pyranose and furanose forms of glucose.

• Ketose = 2nd c = 0

• Aldose = 1st - = 0

Pyranose and furanose forms of fructose

C-2 epimers

Glucose and mannose are epimers at which carbon?

Epimers of Glucose

Epimers

Molecules that differ in the position of H and OH at only one carbon

Example of aldoses of physiological significance

L +  D in last C

a-D-Glucuronate (left) and ẞ-L-iduronate (right).

• sugar part

• non-sugar part 

Glycosides are molecules made of __ [2]

glycone

sugar part of glycoside is callled as ____ ?

aglycone

non- sugar part of glycoside is callled as ____ ?

• Methanol

• glycerol

• sterol

• phenol

• base like adenine

Examples of aglycone (non-sugar part) include ___ [5]

• Digitalis

• Digoxin

• Strophanthus/Ouabain

Cardiac Glycosides examples [3]

Heart failure (CHF)

Cardiac glycosides (like Digitalis, Digoxin, Strophanthus/Ouabain) are used to treat:

A. Diabetes mellitus

B. Hypertension

C. Heart failure (CHF)

D. Asthma

Na⁺-K⁺-ATPase

Cardiac glycosides work by blocking which enzyme?

A. Lipase

B. Na⁺-K⁺-ATPase

C. Amylase

D. DNA polymerase

True

[T/F]

• Blocking Na⁺-K⁺-ATPase in heart cells causes to stop the potassium from going in and sodium from going out of heart cells

Calcium channels to open → more calcium inside → stronger heart contraction

Increased sodium inside heart cells causes:
A. Calcium channels to open → more calcium inside → stronger heart contraction
B. Potassium channels to open → less contraction
C. No change in contraction
D. Weaker heart contraction

An anti-tubercular (aminoglycoside) antibiotic

Streptomycin is classified as:
A. A cardiac glycoside
B. An anti-tubercular (aminoglycoside) antibiotic
C. A lipid molecule
D. A steroid hormone

Streptomycin

It is an antibiotic made of amino sugars linked by glycosidic bonds.

Hyaluronic acid (connective tissue)

[AMINO SUGAR]

D-glucosamine is part of:
A. Chondroitin (cartilage)
B. Hyaluronic acid (connective tissue)
C. DNA backbone
D. Glycogen

connective tissue

hyaluronic acid is a substance in _____ tissue

cartilage

chondroitin  can be found in _____

Chondroitin (cartilage)

D-galactosamine is part of:
A. Hyaluronic acid
B. Chondroitin (cartilage)
C. Glycogen
D. DNA

Chondroitin

D-mannosamine is part of:

A. Chondroitin

B. Hyaluronic acid

C. DNA

D. Glycogen

Macrolide antibiotic

Erythromycin is classified as a:
A. Glycoprotein
B. Macrolide antibiotic
C. Aminoglycoside antibiotic
D. Steroid

Erythromycin

____- is a macrolide antibiotic with a large ring and a ketone group, plus amino sugars linked by glycosidic bonds.

Streptomycin

_____- is an aminoglycoside antibiotic made of amino sugars linked together.