CARBOHYDRATES Flashcards
Considered as the most
abundant molecules on earth
and is the simplest among
other types of organic
compounds.
CARBOHYDRATES (CHO)
Empirical Formula of carbs
CH2O
Referred to as saccharides,
meaning “sugars”
CARBOHYDRATES
FUNCTIONS OF CARBOHYDRATES (give at least 4)
- Main source of energy for our body.
- Protein-sparing function
- Necessary for normal fat metabolism
- Cellulose stimulate peristaltic movement of our
gastrointestinal tract and adds “bulk” in our stool - Lactose promotes the growth of beneficial bacteria, causing
laxative action. - Glucose is the sole source of energy in our brain and proper
functioning of our tissues. - Certain products of carbohydrate metabolism act as catalyst
• A covalent bond that
is formed between a
carbohydrate
molecule and another
molecule such as
between two
monosaccharides.
GLYCOSIDIC BOND
Occurs in the tissues
such as the conversion
of galactose in the
liver to glucose. The
conversion is
catalysed by an
enzyme epimerase.
EPIMERIZATION
• Sugars with aldehyde function
or an acetal equivalent
• The monosaccharide is an
aldehyde if the carbonyl group
is at the end of the carbon
chain.
Aldose
Sugars having a ketone
function or an acetal
equivalent
• The monosaccharide is a
ketone if the carbonyl group is
at any other position.
Ketose
example of an aldose
glyceraldehyde
example of a ketose
dihyroxyacetone.
Sugars oxidized by
Tollens’ or Benedict’s or
Fehling’s reagents.
REDUCING
Sugars not oxidized by
Tollens’ or other reagents.
NON-REDUCING
• Consist of a single
polyhydroxy
aldehyde or ketone
unit
• Smallest
carbohydrates with
3-7 (5-6)carbon
MONOSACCHARIDES “Simple Sugars”
• Most common
monosaccharide
• Formula: C6H12O6
GLUCOSE
• Sweetest of simple
sugar that are
found in sucrose,
honey, fruits, and
vegetables.
• Formula: C6H12O6
FRUCTOSE
• A part of lactose
or a product of
lactose
breakdown.
• Formula: C6H12O6
GALACTOSE
• Composed of
short chains of
monosaccharides
that are joined together
OLIGOSACCHARIDES
• Are the most
abundant with two
monosaccharide
units that are joined
together through
dehydration
synthesis.
DISACCHARIDES (di-”two”)
•This sugar is formed
when a monomer of
glucose bonds to a
monomer of fructose.
A. SUCROSE
• Consist of
monomers of
glucose and
galactose
LACTOSE
Formed from
bonds of two
glucose
monomers.
MALTOSE
Composed of many
molecules of simple
sugar
POLYSACCHARIDES (Poly-”many”)
• Made up the cell wall of
plants
• Helps in lowering the glucose
level in the blood of people
with diabetes.
• It is also essential in
manufacturing numerous
products, including paper,
textiles and pharmaceuticals.
CELLULOSE
• These complex carbs have
the same structures and
functions.
• They supply energy for
longer period
• Since they are not
water-soluble, they need
digestive enzyme known as
“amylase” to break them apart
STARCH AND GLYCOGEN
• Formed from the
breakdown of starch, is obtained from
starch by the
application of heat or
acids.
• They are mainly used as
adhesives and
thickening agents.
Dextrin
• Sources from fruits
and are often used as
a base for jellies.
PECTIN
• Indigestible sugar that
is found in agar, pectin,
woody fibres, leaves, stems
HEMICELLULOSE
• Important in
medicine and nursing
as it provides test for
renal function.
• It is considered as a
“prebiotic fibre” as
it is fermented by
bacteria that
normalise our colon.
INULIN
The sum of all
chemical reactions
required for the
nutritional and
functional activities of the cell
METABOLISM
FOUR SPECIFIC OBJECTIVES OF METABOLISM:
- To extract chemical energy from the environment such as
from organic nutrients or from the sunlight. - To convert exogenous nutrients to building blocks or
precursors of macromolecular components of the cell. - To assemble building blocks into CHO, CHON, LIPIDS,
NUCLEIC ACIDS and another characteristic cell compound - To form (anabolism) and degrade (catabolism) these
biomolecules needed for the specialised functions of the cell.
Food particles do not
become part of our body
tissues but are oxidised to produce energy
Exogenous
Food particles become
part of our body tissues.
Endogenous
containing
carbohydrate-splitting enzymes that is
released in the small intestine
Pancreatic juice
absorbed into
the mucosa cells of the intestine.
Monosaccharides
As glycogen in liver and
muscles, when these
reserves are filled, it is
converted to _______ and
deposited in ______
triglyceride, adipose tissue
If blood glucose
exceeds renal
threshold
(____mg/dL), it will
be excreted in urine
180mg/dl
CONCENTRATION
OF BLOOD SUGAR
Fasting blood
glucose (8-12
hours after the
last meal) is 70-110 mg/dL
SOURCES OF
BLOOD GLUCOSE
▪ Dietary
carbohydrates
▪ Glycogenolysis
▪ Gluconeogenesis
A sequence of
chemical
reactions
undergone by a
compound or class
of compound in a living organism
METABOLIC PATHWAYS
The process of oxidizing food molecules,
like glucose, to carbon dioxide and water
CELLULAR RESPIRATION
The process by which a cell
uses O2 to “burn” molecules
and release energy.
AEROBIC CELLULAR
RESPIRATION
This process allows
organisms to convert energy
for their use without the
presence of oxygen.
ANAEROBIC CELLULAR
RESPIRATION
Access of glucose to the
cell can be regulated
using the __________ proteins that
transport glucose.
glucose transporter
▪ From Greek word
“glykys”, meaning
“sweet” and “lysis”
which means “breaking”
▪ Initially explained by
Gustav Embden and Otto
Meyerhof
▪ The process of converting
glucose into energy.
GLYCOLYSIS
in the process of glycolysis, The enzyme
_________
phosphorylates glucose
in the cell’s cytoplasm.
In the process, a
phosphate group from
ATP is transferred to
glucose producing
glucose 6-phosphate.
hexokinase