CARBOHYDRATES I Flashcards
is a chemical substance found within a living organism.
Biochemical substance
2 Kinds of Biochemical Substance:
substances that do not contain C in their structure: water inorganic compounds (salt)
Bio-inorganic substances
2 Kinds of Biochemical Substance:
include carbohydrates, lipids, proteins, and nucleic acids.
Bio-organic substances
is the most abundant bioorganic molecules on Earth (however, its abundance on the human body is relatively low).
Carbohydrates
Occurrence and Functions of Carbohydrates :
provides energy
Major food source/ energy supplies of our body
Primary source for the brain, erythrocytes, and retinal cells
Carbohydrate oxidation
Occurrence and Functions of Carbohydrates :
in the form of glycogen (stored form of carbohydrates), provides a short-term energy reserve
Thru the intake of food, if not yet needed, it could be stored in form of glycogen
Carbohydrate storage
Stored in liver (diff biochemical metabolism) and muscles
Occurrence and Functions of Carbohydrates :
Carbohydrates supply ___ atoms for the synthesis of other biochemical substances (proteins, lipids, and nucleic acids)
carbon
(Plays key role in diff biochemical metabolism/ processes
Building block for many processes of metabolism
Central ingredient for life)
Occurrence and Functions of Carbohydrates :
Carbohydrates form part of the structural framework of ___ and ___ molecules
DNA . RNA
DNA and RNA monomer unit (nucleotide) one of its 3 major component is sugar
Type of sugar component:
DNA: ____
RNA: ____
deoxyribose
ribose
Occurrence and Functions of Carbohydrates :
Carbohydrates linked to lipids are _____ ______ of cell membranes
structural component (Glycolipid: carbohydrate attached to a lipid)
Occurrence and Functions of Carbohydrates :
Carbohydrates linked to proteins function in a variety of cell–cell and cell–molecule ____ processes
recognition
carbohydrate attached to a protein; marker for recognition between different cell/ molecule
Glycoprotein
General/ Empirical formula for CHO:
CnH2nOn; applicable for monosaccharides
Different Derivatives of CHO (PSA)
Phosphate
Sulfates
Amides
Classification of Carbohydrates based on the Functional Group:
RCHO
polyhydroxy aldehyde
Classification of Carbohydrates based on the Functional Group:
RCOR
polyhydroxy ketone
Classification of Carbohydrates based on the Generic Classification/ Size of base C chain: 3C : triose 4C : \_\_\_\_ 5C : \_\_\_\_ 6C : \_\_\_\_ 7C : \_\_\_\_
tetrose
pentose
hexose
heptose
Means that all sugars contain more than 1 or several hydroxyl groups (OH) found in the chain; regardless of types and could be named according to the functional group
Polyhydroxy
Classification of Carbohydrates based on the Number of sugar units/ base on molecular size:
1 sugar unit : ___
2 sugar unit: ___
2-10 sugar units : _____
multiple sugar units (monosaccharides are the base units) : ____
monosaccharide
disaccharide
oligosaccharide
polysaccharide
same type of bonds, order, or formula but differ in arrangement of carbohydrates = differ the property of the said compound
Stereoisomers
Classification of Carbohydrates:
also known as monoses or glycoses are classified as aldose or ketose on the basis of the type of carbonyl present.
Simplest unit/ the monomer unit for diff types of complex carbohydrates (1 sugar unit)
Monosaccharides
How many carbon components are there in deoxyribose and ribose?
5 C
ROR or RCHO:
is always found in the terminal end or in the carbon 1.
RCHO (aldehyde)
ROR or RCHO:
is always found in carbon 2 because there should be an alkyl group prior to the carbon which contains the double bond.
ROR (ketone)
Cannot be broken down into smaller units as it is the monomer unit. It is also called as simple sugars. 99% of them are straight-chained compounds.
Monosaccharides
e.g. ketoheptose, aldopentose
simplest aldose
D- glyceraldehyde or aldotriose
Classification of Carbohydrates:
are glycosides formed from the linkage of two monosaccharides.
Disaccharides
linkage found bet 2 or more monosaccharides/ monomer units forming a complex CHO (covalent bond)
Glycosidic linkage/ bond
e.g. lactose, maltose, sucrose
Handedness in Molecules: Objects and Mirror Images
Chirality
are images that coincide at all points when the images are laid upon each other (exactly the same)
Superimposable mirror images
are images where not all points coincide when the images are laid upon each other (diff from each other)
Non-superimposable mirror images
Molecules which tend to have superimposable mirror images are called
achiral molecule
Molecules which tend to have non-superimposable mirror images
chiral molecule
is an atom in a molecule that has four different groups bonded to it in a tetrahedral orientation.
chiral center
A if only the first statement is true
B if only the second statement is true
C if both statements are true
D if both statements are false
A molecule that contains a chiral center is said to be chiral.
A carbon atom involved in a multiple bond (double or triple bond) cannot be a chiral center since it has a fewer than four groups bonded to it.
C
A if only the first statement is true
B if only the second statement is true
C if both statements are true
D if both statements are false
There should be no attached two or more similar groups to a carbon to be a chiral center.
A chiral molecule is a molecule whose mirror images are not superimposable.
C
Atoms of stereoisomers are connected in the same way but are arranged differently in space, but same structure
Isomerism
2 Types of Stereoisomerism:
have structures that are nonsuperimposable mirror images of each other.
Have single chiral center
Left and right handedness
Enantiomers
Enantios (Greek)= opposite
2 Types of Stereoisomerism:
have structures that are not mirror image of each other
Cis-, Trans-
Can contain more than 1 chiral center; can have left and right handedness
Diastereomers
is a two-dimensional structural notation for showing the spatial arrangement of groups about chiral centers in molecules
Fischer projection formula
A if only the first statement is true
B if only the second statement is true
C if both statements are true
D if both statements are false
D and L system/ designation is used to designate the handedness of glyceraldehyde enantiomers/ molecule or carbohydrates.
Functional groups of high priority will be written at the top (aldehyde; imp or ketone).
C
D or L:
right (almost all monosaccharides)
D (dextro)
D or L:
left (almost all amino acids, proteins)
L (levo)
TRUE OR FALSE:
The D,L system used to designate the handedness of glyceraldehyde enantiomers can be extended to other monosaccharides with more than one chiral center.
TRUE
TRUE OR FALSE:
The carbon chain is numbered starting at the carbonyl group end of the molecule, and the highest-numbered chiral center is used to determine D or L configuration.
TRUE
A six-carbon monosaccharide with an aldehyde functional group is an _____
A five-carbon monosaccharide with a ketone functional group is a _____
aldohexose
ketopentose
Biochemically Important Monosaccharides:
is the most abundant in nature and the most important from a human nutritional standpoint.
Aldohexose; 6C, most common monosaccharide, uses it as a source of energy and metabolic intermediate
D-glucose
(dextrose, blood sugar, grape sugar (good source of glucose)
Six membered cyclic form: Pyranose
Central pivotal point of CHO metabolism)
Biochemically Important Monosaccharides: (Glucose or Fructose)
is biochemically the most important ketohexose
also known as levulose and fruit sugar (good dietary sugar)
D-Fructose
(Sweetest tasting, seen in semen, preservative for food and IV nutrient
More water soluble than glucose
Molecular: C6H12O6
Five membered cyclic form: Furanose because of the double bond found in C-2
Biochemically Important Monosaccharides: (Galactose and Ribose)
aldohexose: Milk sugar
Synthesize in human; brain sugar (part of brain and nerve tissue)
Used to differentiate blood types: A, B, AB, O
Six membered cyclic form (Haworth Projection): Pyranose
Functional group: aldehyde, 6C
D-Galactose
(Difference from Glucose is the OH that is found on C-4
Less sweet than glucose; seldom encountered as free monosaccharides
Once it is digested it will be immediately converted into glucose
Galactosemia: genetic disorder of newborns; difficulty in converting galactose to glucose)
Biochemically Important Monosaccharides:
aldopentose
Part of RNA, ATP, and DNA
Five membered cyclic form, same as fructose (5 membered): Furanose
D-Ribose
2 Forms of D-Glucose:
-OH of C1 and CH2OH of C5 are on opposite sides
Alpha-form
2 Forms of D-Glucose:
-OH of C1 and CH2OH of C5 are on same sides
Beta-form
A cyclic monosaccharide containing a 6-atom ring is called a _____
One containing a 5-atom ring is called _____
Pyranose
Furanose
(because their ring structures resemble the ring structures in the cyclic ethers pyran and furan respectively)
is a two-dimensional structural notation that specifies the three-dimensional structure of a cyclic form of a monosaccharide.
Haworth Projection Formulas: Walter Norman Haworth (forms a cyclic form) Right OH (Fisher): Downward (Haworth) Left OH (Fisher): Upward (Haworth)
Beta configuration, both of these groups (OH and CH2OH) point in the ____direction
Alpha configuration, the two groups point in____ directions.
same
opposite
Reactions of Monosaccharides:
The redox chemistry of monosaccharides is closely linked to the alcohol and aldehyde functional groups present in them
Usually that undergo are aldoses
Oxidation (to acidic sugars)
Oxidation can yield three different types of acidic sugars depending on the type of oxidizing agent used
Reactions of Monosaccharides:
The carbonyl group in a monosaccharide (either an aldose or a ketose) is reduced to a hydroxyl group using hydrogen as the reducing agent.
Reduction (to sugar alcohols)
is an acetal formed from a cyclic monosaccharide by replacement of the hemiacetal carbon -OH group with an -OR group.
Glycoside
The monosaccharides responsible for blood groups are ____ and its derivatives.
D-galactose
(Found on the surface of RBCs)
N-acetyl galactosamine (A)
D-galactosamine (B)
The hydroxyl groups of a monosaccharide can react with inorganic oxyacids to form inorganic esters
Phosphate ester formation
(Phosphate esters of various monosaccharides are stable in aqueous solution and play important roles in the metabolism of carbohydrates)
e.g. Glucose-1 phosphate, Glucose-6 phosphate
derivative of glucose
Involved in a lot of metabolism/ biochemical process
Very important in conversion of glucose to diff products
Very important for the RBCs
Glucose-6-phosphate dehydrogenase (G6PD)
(G6PD deficiency: doesn’t have the G6PD enzyme, RBCs have difficulty in breaking down G6P
Hereditary, can be known via newborn screening
Can cause hemolytic anemia)
one of the hydroxyl groups of a monosaccharide is replaced with an amino group (OH—> NH2)
Amino Sugar Formation
(Amino sugars and their N-acetyl galactosamine derivatives are important building blocks of polysaccharides)
Ex: Glucose —> Glucosamine, Galactose —> Galactosamine
Amines: NH2
