CARBOHYDRATES Flashcards
1
Q
Are aldehyde or ketone derivatives of polyhydric alcohols consisting of carbon, hydrogen, and oxygen
A
CARBOHYDRATES
2
Q
carbohydrates consists of
A
carbon, hydrogen, oxygen
3
Q
carbohydrates are ____ and ____ derivatives
A
aldehyde & ketone
4
Q
carbohydrates can be classified as ____ and ____
A
aldoses & ketoses
5
Q
have many OH in their structure
A
polyhydric alcohol
6
Q
general formula for carbohydrates
A
(CnH2O)n
7
Q
carbohydrates that are found in foods such as fruits, milk, and vegetables
A
simple carbohydrates
8
Q
carbohydrates that provide vitamins, minerals, and fiber.
foods such as bread, legumes, rice, pasta, and starchy vegetables
A
complex carbohydrates
9
Q
IMPORTANCE OF CARBOHYDATES
Provide a significant fraction of the ____ in the diet of most organisms
A
ENERGY
10
Q
IMPORTANCE OF CARBOHYDATES
____ form of energy in the body
A
STORAGE
11
Q
storage form of carbohydrates in plants
A
STARCH
12
Q
storage form of carbohydrates in humans
A
GLYCOGEN
13
Q
glycogen is stored in what organs
A
liver, muscle
14
Q
IMPORTANCE OF CARBOHYDATES
Cell membrane components that mediate some forms of ____
A
intercellular communication
15
Q
IMPORTANCE OF CARBOHYDATES
carbohydrate in the CELL WALLS OF BACTERIA
A
PEPTIDOGLYCAN
16
Q
IMPORTANCE OF CARBOHYDATES
carbohydrate in the EXOSKELETON OF MANY INSECTS
A
CHITIN
17
Q
IMPORTANCE OF CARBOHYDATES
carbohydrate that is the FIBROUS component of the PLANT CELL WALL
A
CELLULOSE
18
Q
a structural polysaccharide
A
CELLULOSE
19
Q
IMPORTANCE OF CARBOHYDATES
Serves as ____ of many organisms
A
STRUCTURAL COMPONENT
20
Q
IMPORTANCE OF CARBOHYDATES
____ contains sugar as an essential features of their structure;
A
plant metabolites
21
Q
beside a sugar
A
glycoside
22
Q
non sugar component of glycoside
A
AGLYCONE
23
Q
sugar component of glycoside
A
GLYCONE
24
Q
IMPORTANCE OF CARBOHYDATES
Play an ____ in plant-animal interaction, protection from wound and infection and detoxification of foreign substances
A
ECOLOGICAL ROLE
25
# **IMPORTANCE OF CARBOHYDATES**
____ and ____ are used as **food** and **pharmaceutical**.
SUGAR & STARCH
26
* The **most important** carbohydrate;
* Dietary carbohydrate **absorbed** into the **bloodstream**;
* **Major metabolic fuel** of **mammals** and **universal fuel** of the **fetus**.
GLUCOSE
27
Glucose is **classified/categorized** as ____
ALDOHEXOSE
28
**synonym** of glucose
blood sugar
29
Glucose is a **precursor** for the **synthesis** of what **nucleic acids**
DNA & RNA
30
Glucose is a **precursor** for the **synthesis** of ____ -- in **lactose** of **milk**, in **glycolipids**, and in combination with protein in **glycoproteins** and
**proteoglycans**
GALACTOSE
31
# **Disease associated with Carbohydrate Metabolism**
disease that **cannot digest** & **lacks** **β-1,4 enzymes**
lactose intolerant
32
# **Disease associated with Carbohydrate Metabolism**
previously considered as a **hereditary** disease, but now a **lifestyle** disease
DIABETES MELLITUS
33
# **Disease associated with Carbohydrate Metabolism**
* has **galactose** in the **bloodstream** instead of glucose
* a **metabolic disorder** that can lead to **lens opacity** and **cataract** formation
GALACTOSEMIA
34
# **CARBOHYDRATES**
**ratio** of **carbon** molecule to **water** molecule
1:1
| in every carbon, there is 1 water molecule
35
the **1:1 ratio** of carbon & water in carbohydrates is only applicable to ____
monosaccharides
36
**carbohydrate** is also known as
hydrate of carbon
37
* “**simple sugars**”
* **Cannot** be **hydrolyzed** into **simpler** carbohydrates;
* Contains a **single** polyhydroxy aldehyde or ketone unit
MONOSACCHARIDE
38
**glucose**, **fructose**
MONOSACCHARIDE
39
# **MONOSACCHARIDE**
**Cannot** be **hydrolyzed** into ____
SIMPLE CARBOHYDRATES
40
# **MONOSACCHARIDE**
Contains a ____ polyhydroxy **aldehyde** or **ketone** unit
SINGLE
41
# **MONOSACCHARIDE**
classification is based on:
* number of C
* whether they have **aldehyde** or **ketone** group
42
classification of **glucose**
aldohexose
43
classification of **fructose**
ketohexose
44
**simplest aldose**
glycerose / glyceraldehyde
45
**simplest ketose**
dihydroacetone
46
Most **monosaccharides** have a ____ taste;
sweet
47
**solubility** of monosaccharides
very soluble in water
48
monosaccharides are ____ at **room temperature**
solid
49
as the **saccharide unit increases**, the solubility in water ____
DECREASES
50
**basis** for the **relative sweetness**
SUCROSE - 1.00
51
found on **caramelized sugar**
invert sugar
52
**fruit** sugar
fructose
53
inverted sugar is **brown** due to
levulose
54
**sweetest** sugar
fructose
55
anomeric carbon for glucose
C1
56
**most predominant** form of glucose
β-D-glucose
57
**monosaccharides** form ____ ring
pyranose
57
58
how many **stereoisomers** are **possible** in the **structure of glucose**
2
59
**fructose** form ____ ring
furanose
60
D-glucose in solution
dextrose
61
anomeric carbon for **fructose**
C2
62
# **TESTS FOR CARBOHYDRATES**
* **aldehydes** and **ketones** that have an **OH group on the carbon next to the carbonyl group** react with a basic solution of Cu+2 (**Benedict's reagent**) to form a **red-orange precipitate** of copper(I) oxide (Cu2O)
* sugars that undergo this reaction are called **reducing sugars**
OXIDATION OF MONOSACCHARIDES
63
# **TESTS FOR CARBOHYDRATES**
**reagent** used for the **oxidation of monosaccharides**
BENEDICT'S REAGENT
64
# **TESTS FOR CARBOHYDRATES**
**result** for oxidation of monosaccharides
red-orange precipitate
65
# **TESTS FOR CARBOHYDRATES**
sugars that undergo **oxidation** are called
reducing sugars
66
all of the ____ are **reducing sugars**
monosaccharides
67
____ can form at the **6-carbon** of **aldohexoses** and **aldoketoses**
phosphate esters
68
found in the **sugar-phosphate backbone** of **DNA & RNA**, in **ATP**, and as **intermediates** in the **metabolism** of **carbohydrtaes** in the body
phosphate esters of monosaccharide
69
**seven**-carbon sugar
sedoheptulose
70
derivatives of **trioses**, **tetroses**, & **pentoses** & **sedoheptulose**
monosaccharides
71
**monosaccharides** are formed as ____ in **glycolysis** and **pentose phosphate pathway**
metabolic intermediates
72
# **MONOSACCHARIDES**
are important in **nucleotides**, **nucleic acids** and **several coenzymes**
PENTOSES
73
# **MONOSACCHARIDES**
**glucose**, **galactose**, **fructose**, and **mannose**
HEXOSES
74
monosaccharides are ____ **derivatives** of **glucose**
carboxylic acid
75
# **MONOSACCHARIDES**
for **glucuronide formation** and in **glycosaminoglycans**
D-glucuronate
76
# **MONOSACCHARIDES**
metabolic derivatives of **D-glucuronate**
| (in **glycosaminoglycans**)
L-iduronate
77
# **MONOSACCHARIDES**
an intermediate in the **uronic acid pathway**
L-gulonate
78
* Meaning "**two sugars**“
* Are commonly found in nature as **sucrose**, **lactose** and **maltose** (LSM)
* Formed by a **condensation reaction** where one molecule of water condenses or is released during the joining of two monosaccharides
DISACCHARIDES
79
**disaccharides** are formed by what reaction
condensation reaction
80
The **type of bond** that is formed **between** the **two sugars is called**
GLYCOSIDIC BOND
81
**disaccharides** are found commonly in nature as ____, ____, ____
lactose, sucrose, maltose
| LSM
82
* An **excellent preservative** because it has **no "reducing end"** or **reactive group** like the other sugars
* Other natural sources are found in plants such as **sugar cane**, **sugar beets**, and **maple syrup**
* **Hydrolysis** yields mixtures of **glucose** and **fructose** called **“invert sugars”**
SUCROSE
83
# **SUCROSE**
An **excellent preservative** because it has no ____ or ____ like the other sugars
reducing end or reactive group
84
# **SUCROSE**
**Hydrolysis** of sucrose yields **mixtures** of **glucose** and **fructose** called
inverted sugars
85
* **beta-glycosidic bonds** are **unable** to be **digested** by some people
* Many people are lactose intolerant and suffer from intestinal cramping and bloating due to the **incomplete digestion** of the substance
LACTOSE
86
**Isomaltose**, **maltose**, lactose, **lactulose**, sucrose and **trehalose**
DISACCHARIDES
87
α-D-**Gluco**pyranosyl-(**1→2**)-β-D-**fructo**furanose
SUCROSE
88
β-D-**Galacto**pyranosyl-(**1→4**)-α-D-**gluco**pyranose
LACTOSE
89
α-D-**Gluco**pyranosyl-(**1→4**)-β-D-**Gluco**pyranose
MALTOSE
90
**oligo** means
few
91
**Important oligosaccharides** are ____ and ____ which are found in **beans** and **legumes**
raffinose
stachyose
92
* **Raffinose** and **stachyose**, because of their **unique glycosidic bonds**, **cannot be broken down** into their simple sugars.
* Therefore, they **cannot be absorbed** by the **small intestine** and are often **metabolized by bacteria** in the **large intestine** to form **unwanted gaseous** by-products.
OLIGOSACCHARIDES
93
* **Condensation products** of **more than ten** monosaccharide units;
* **not reducing sugars**, since the **anomeric carbons** are **connected through glycosidic linkages**
POLYSACCHARIDES
94
**not digested by human enzymes**, and are **major component of dietary fibers**
non starch polysaccharides
95
a **glucose** polymer
cellulose
96
a **fructose** polymer
inulin
97
**polysaccharides** are classified as
homoglycan
heteroglycan
98
**same** set of monosaccharides
HOMOGLYCAN
99
**different** sets of monosaccharide
HETEROGLYCAN
100
# **HETEROGLYCAN or HOMOGLYCAN**
glucan / glucosan
fructosan
HOMOGLYCAN
101
# **HETEROGLYCAN or HOMOGLYCAN**
gums & mucilages
HETEROGLYCAN
102
* **Homopolymer** of D glucose units forming an **α-glucosidic chain** (called **glucosan** or **glucan**);
* ____ (and other glucose polymers) are usually **insoluble** in water because of **high molecular weight**;
* the **major storage form** of carbohydrates in **plants** and of two different forms: **amylose** and **amylopectin**
STARCH
103
# **STARCH**
* consists of **long**, **unbranched** chains of glucose (from **1000** to **2000** molecules) connected by **α(1→4)** glycosidic linkages
* **10-20%** of starch in plants is in this form
* its **chain** is **flexible** enough to allow the molecules to **twist into the shape of a helix**. Because it **packs more tightly**, it is **slower to digest** than other starches
AMYLOSE
104
**amylose helices** can ____ molecules of **iodine**, formaing a characteristic **deep blue-purple color**
TRAP
105
**amylose helices** can **trap** molecules of **iodine**, formaing a characteristic ____ color
deep blue-purple
106
often used as a **test** for the **presence of starch**
IODINE
107
**amylose** contains what glycosidic linkage
α(1→4)
108
# **STARCH**
* consists of **long chains of glucose** (up to **10⁵** molecules) connected by **α(1→4) glycosidic linkages**, with **α(1→6) branches every 24 to 30 glucose units** along the chain
* **80-90%** of the starch in plants is in this form
AMYLOPECTIN
109
glycosidic linkages found in **amylopectin**
α(1→4) & α(1→6)
110
**color** of **amylopectin** in **iodine TS**
blue-violet
111
* **Measure** of **digestibility** of starchy food
* Based on the extent to which it **raises the blood concentration of glucose** compared with an equivalent amount of glucose or a reference food such as white bread or boiled rice.
GLYCEMIC INDEX
112
* also known as ***animal starch***, is **structurally similar to amylopectin**, containg both α(1→4) glycosidic linkages and & α(1→6) branch points
* even **more highly branched**, with branches occuring every **8 to 12** glucose units
* **abundant** in the **liver** and **muscles**
* on hydrolysis it forms **D-glucose** which maintains **normal blood sugar level** and **provides energy**
GLYCOGEN
113
the **branching** in **amylopectin** occurs every ____
24 to 30 glucose units
114
the **branching** in **glycogen** occurs every ____
8 to 12
115
**Glycogen** forms ____ in **hydrolysis** which **maintains normal blood sugar level** and **provides energy**
D-glucose
116
# **STARCH**
unbranched
AMYLOSE
117
# **STARCH**
branched
AMYLOPECTIN
118
highly branched
| (animals)
GLYCOGEN
119
**color** of **glycogen** in **iodine TS**
reddish brown
120
* **most abundant organic substance** on earth
* a polymer consisting of long, ***unbranched*** chains of D-glucose connected by **β(1→4)** glycosidic linkagaes
* it may contain from **300 to 3000** glucose units in one molecule
CELLULOSE
121
glycosidic linkages of **cellulose**
β(1→4)
122
* a polymer of **N-acetylglucosamine**, an amide derivative of the ***amino sugar*** -- **glucosamine**, in which **one of the OH groups** is **converted to an amine (NH2) group**.
* the polymer is **extremely strong** becasue of the **increased hydrogen bonding** provided by the **amide groups**
CHITIN
123
an amide derivative of the ***amino sugar*** -- **glucosamine**
N-acetylglucosamine
124
* A polysaccharide of **fructose** found in **tubers** and **roots** of dahlias, artichokes, and dandelions
* **Readily soluble** in water
* Use to **determine glomerular filtration**
* **Not hydrolyzed** by **intestinal enzymes**
INULIN
125
Intermediates in the **hydrolysis of starch**
dextrins
126
**GLYCOSAMINOGLYCANS** is also known as
mucopolysaccharides
127
* **Complex carbohydrates** containing **amino sugars** and **uronic acid**;
* May be **attached in protein** molecule to **form proteoglycan**.
GLYCOSAMINOGLYCANS
or mucopolysaccharides
128
* provide the **ground** or **packing substance** of **connective tissues**;
* **Hold large quantities** & **water supply**, occupies space **lubricating** other structures.
PROTEOGLYCANS
129
* Proteins containing **branched** & **unbranched oligosaccharide chains**;
* They occur in the **cell membranes** and many other situations;
GLYCOPROTEINS
130
example of **glycoproteins / mucoproteins**
serum albumin
130
**GLYCOPROTEINS** is also known as
mucoproteins
131
**nine** carbon sugar derived from **mannosamine** and **pyruvate**
NEURAMINIC ACID
132
* are **N-** or **O-acyl** derivatives of **neuraminic acid**
* Constituents of both **glycoproteins** & **gangliosides (glycolipids)**
* important in **viruses** (esp. those with **influenza**)
SIALIC ACID
133
Are formed by the **condensation** between the **hydroxyl** group of the **anomeric carbon of monosaccharide (glycone)**, and a second compound that may not be another **monosaccharide (aglycone)**
GLYCOSIDES
134
# **GLYCOSIDES**
* **most stable** glycoside
* **resistant** to **hydrolysis**
C-glycoside
135
# **GLYCOSIDES**
* if the **second group** is a **hydroxyl**
* **Acetal link** (formed from an **aldehyde** and an **–OH**)
O-glycoside
136
# **GLYCOSIDES**
* if the **second group** is **amine**
* Ex.: **adenine** and **ribose** in **ATP**
N-glycoside
137
# **GLYCOSIDE**
If the **hemiacetal** (aldehyde + -OH) portion is **glucose**, the resulting compound is ____
GLUCOSIDE
138
# **GLYCOSIDE**
If the **hemiacetal** (aldehyde + -OH) portion is **galactose**, the resulting compound is ____
GALACTOSIDE
139
# **GLYCOSIDES**
may be **methanol**, **glycerol**, a **sterol**, a **phenol**, or a **base** such as **adenine**
AGLYCONE
140
# **MEDICINALLY IMPORTANT GLYCOSIDES**
* Contain **steroids** as **aglycone**
* Include derivatives of **digitalis** (**digoxin**, **digitoxin**) and **strophantus** (**ouabin**)
CARDIAC GLYCOSIDE
141
derivatives of **digitalis**
digoxin, digitoxin
142
derivatives of **strophantus**
ouabin
143
# **MEDICINALLY IMPORTANT GLYCOSIDES**
streptomycin
aminoglycoside antibiotics
144
* **Lack an oxygen atom**
* one hydroxyl group has been **replaced by hydrogen**
* **deoxyribose** in DNA
DEOXYSUGARS
145
DNA is **deoxygenated** at what carbon
C2
146
deoxysugar in **glycoproteins**
L-fructose
147
used experimentally as **inhibitor of glucose metabolism**
2-deoxyglucose
148
are components of **glycoproteins**, **gangliosides**, & **glucosaminoglycosides**
HEXOSAMINES
149
constituent of **hyaluronic acid**
D-glucosamine
150
constituent of **chondroitin**
D-galactosamine (chondrosamine)
151
AMINOSUGARS
D-glucosamine
D-galactosamine (chondrosamine)
D-mannosamine
Aminoglycosides antibiotics & macrolides
152
**simplest** carbohydrate that exists in **two** isomeric forms
GLYCERALDEHYDE
153
**glyceraldehyde** is a ____ molecule -- it c**annot be superimposed** on its mirror imnage
CHIRAL
154
the **two mirror-image forms** of **glyceraldehyde** are ____ of each other
ENANTIOMERS
155
**glucose** can form ____ isomers
16
156
* **Mirror images**
* Determined by **spatial relationship** to the parent compound of the carbohydrates
D & L isomerism
157
OH group is on the **right**
D-isomer
158
OH group is on the **left**
L-isomer
159
Most **monosaccharides** in **mammals** are
D-sugars
160
**Two possible structures** for the **pyranose** and **furanose** forms of a monosaccharide
Alpha and beta anomers
161
OH down
alpha
162
OH up
beta
163
6 membered ring
5 carbon
1 oxygen
PYRANT
164
5 membered ring
4 carbon
1 oxygen
FURAN
165
* Sugars that **differ** in **configuration** at **ONLY 1 POSITION**
* Isomers differing as a result of **variations in configuration** of the **–OH** and **–H** on carbon atoms 2, 3, and 4 glucose (epimers of glucose)
* Examples:
▫ D-glucose & D-galactose (epimeric at C4)
▫ D-glucose & D-mannose (epimeric at C2)
▫ D-idose & L-glucose (epimeric at C5)
EPIMERS
166
# **EPIMERS**
D-**glucose** & D-**galactose**
epimeric at ____
C4
167
# **EPIMERS**
D-**glucose** & D-**mannose**
epimeric at ____
C2
168
# **EPIMERS**
D-**idose** & D-**glucose**
epimeric at ____
C5
169
* The **most important epimers** of glucose
* Formed by **epimerization** at **carbon 2 and 4**, respectively
MANNOSE & GALACTOSE
170
* are a **convenient way** to **represent mirror images** in **two dimensions**
* place the **carbonyl group** at or near the **top** and the **last achiral CH₂OH** at the **bottom**
FISCHER PROJECTIONS
171
# **OPTICAL ACTIVITY**
substance rotates polarized light to the **left**
LEVOROTATORY
172
# **OPTICAL ACTIVITY**
substance rotatets polarized light to the **right**
DEXTROROTATORY
173
molecules that **rotate** the plane of polarized light
optically active
