PRELIM LEC 3: CARBOHYDRATES Flashcards
Most abundant class of bioorganic molecules on planet earth
CARBOHYDRATES
average human diet should ideally be about _________ by mass
2/3 carbohydrate
________ of calories come from carbohydrates
A 45-65%
B 60-65%
C 55-65%
A 45-65%
2 main uses of Carbs (Plants)
CELLULOSE
STARCH
carbohydrates serve as structural elements
CELLULOSE
provide energy reserves for the plants
STARCH
Empirical formula for many of the simpler Carbohydrates is __________, hence the name ______
(CH2O)n; HYDRATE OF CARBON
Molar ratio of carbohydrates:
1:2:1
a polyhydroxy aldehyde/ketone, or a compound that yields polyhydroxy aldehydes or polyhydroxy ketones upon hydrolysis
CARBOHYDRATE
Functions of Carbohydrates
- a STORAGE FORM OF ENERGY (glycogen)
- SUPPLY CARBON ATOMS for the synthesis of other biochemical substances (proteins, lipids, and nucleic acids)
- form part of the STRUCTURAL FRAMEWORK OF DNA AND RNA MOLECULES
- when linked to lipids: structural components of cell membranes and SERVE AS CELL MEMBRANE COMPONENTS that mediate some forms of intercellular communication (also, structural component of many organisms, including the cell walls of bacteria, the exoskeleton of many insects, and the fibrous cellulose of plants)
- when linked to proteins: function in variety of cell-cell and CELL MOLECULE RECOGNITION PROCESSES
CARBOHYDRATES belongs to a group of molecules known as
SACCHARIDES
Classification of carbohydrates on the basis of molecular size as
monosaccharides
disaccharides
oligosaccharides
polysaccharides
CARBOHYDRATES isomers
FRUCTOSE
GLUCOSE
MANNOSE
GALACTOSE
simple sugars; cannot be hydrolyzed to a simpler form
smallest unit that make up the carbohydrates
can contain 3 or more carbon atoms;
most monosaccharides have a sweet taste**
Glucose-Galactose-Fructose
MONOSACCHARIDES
Occurring monosaccharides are _______
D - ISOMERS
Naturally occurring monosaccharides have from ______ carbon atoms; five and six- carbon species are especially common.
3 TO 7
Example of monosaccharides carbohydrates
GLUCOSE
GALACTOSE
FRUCTOSE
- the most important member of the sugar family
- main source of calories
- can cross the blood-brain barrier (can provide nutrients to the brain)
A GALACTOSE
B GLUCOSE
C FRUCTOSE
B GLUCOSE
TYPES OF GLUCOSE
ALPHA-GLUCOSE
BETA-GLUCOSE
D-GLUCOSE
L-GLUCOSE
- the OH group of C1 is pointing in the SAME DIRECTION to the CH2OH
- function as structural substance
A Beta-glucose
B Alpha-glucose
C D - Glucose
A Beta-glucose
- the OH group of C1 is pointing in the OPPOSITE DIRECTION to the CH2OH
- function as primary source of energy
A Beta-glucose
B Alpha-glucose
C D - Glucose
B Alpha-glucose
- most abundant and most important from a human nutritional standpoint
- Often referred as GRAPE SUGAR
Tastes sweet, nutritious and important component of diet
A Beta-glucose
B Alpha-glucose
C D - Glucose
C D - Glucose
2 OTHER NAMES OF D-GLUCOSE
- BLOOD SUGAR DEXTROSE - blood contain dissolved sugar
- 2 hormones: INSULIN and GLUCAGON
- MILK SUGAR
- D-glucose and D-galactose differ only in the configuration of the –OH group and –H group carbon 4.
- synthesized from the mammary glands for use in lactose (glucose + galactose)
- Only found in nature if it is found in combination with glucose to form lactose
- It is sometimes called BRAIN SUGAR (component of glycoprotein found in brain & nerve tissue)
- is also present in the chemical markers that distinguish various types of blood
A GALACTOSE
B GLUCOSE
C FRUCTOSE
A GALACTOSE
D-glucose and D-galactose differ only in the configuration of the _______________________
A –OH group and -H group carbon 4
B –OH group and -H group carbon 5
C –OH group and -H group carbon 6
A –OH group and -H group carbon 4
GALACTOSE is synthesized from the _____________ for use in lactose
(glucose + galactose)
MAMMARY GLANDS
- SWEETEST-tasting of all sugars
- Found in many fruits, in honey, and root vegetables
A GALACTOSE
B GLUCOSE
C FRUCTOSE
C FRUCTOSE
FRUCTOSE OR D-FRUCTOSE is also known as ______ and ______
LEVULOSE; FRUIT SUGAR
Two monosaccharide are joined by a glycosidic linkage (Glycosidic bonding)
broken down by hydrolysis:
o sucrose (fructose + glucose)
o lactose (galactose + glucose)
o maltose (glucose + glucose)
DISSACHARIDES
- Produced during starch digestion
- Common ingredient in baby food and in malted milk
- Found in molasses which is used to ferment beer
A SUCROSE
B LACTOSE
C MALTOSE
C MALTOSE
- made up of b-d-galactose unit and d-glucose unit joined by a glycosidic linkage
- MILK SUGAR
- Important ingredient in commercially produced infant formula
- Pasteurization of milk quick heating that kills most of the bacteria and retards the souring process
A SUCROSE
B LACTOSE
C MALTOSE
B LACTOSE
- conversion of lactose to lactic acid by
bacteria in milk
SOURING MILK
- ”table sugar”
- alpha glucose 1 and Beta 2 fructose bond
- Found in fruits and vegetables wherein sugar cane and sugar beets have the largest quantities
- formed by plants and not by animals
A SUCROSE
B LACTOSE
C MALTOSE
A SUCROSE
usually found associated with
proteins and lipids in complex molecules that have both
structural and regulatory functions.
A MONOSACCHARIDES
B POLYSACCHARIDES
C FREE OLIGOSACCHARIDES
D DISACCHARIDES
C FREE OLIGOSACCHARIDES
= 3-9 monosaccharides
OLIGO
- Is a carbohydrate that contains 3 to 10 monosaccharide units covalently bonded to each other
- “FREE” oligosaccharides are seldom encountered
- Complete hydrolysis of an oligosaccharide produces
several monosaccharide molecules
OLIGOSACCHARIDES
EXAMPLE OF OLIGOSACCHARIDE
RAFFINOSE
RAFFINOSE CONTAINS..
GALACTOSE
GLUCOSE
FRUCTOSE
- linkage of many monosaccharide units;
- upon hydrolysis, will yield more than 10 monosaccharides; starch-glycogen-chitin-cellulose
POLYSACCHARIDES
- contain only a single type of monosaccharide
- ex. Glucose molecules
- it can be branched or unbranched
A HOMOPOLYSACCHARIDE
B HETEROPOLYSACCHARIDE
A HOMOPOLYSACCHARIDE
-Contain two or more types of monosaccharides
-Ex. Long chain of glucose and fructose molecules
-it can be branched or unbranched
A HOMOPOLYSACCHARIDE
B HETEROPOLYSACCHARIDE
B HETEROPOLYSACCHARIDE
- homopolysaccharide
- excess glucose is converted to starch and stored for later use
- can be broken down by intestinal enzymes
- Found in rice, potatoes, wheat, corn
- Don’t taste sweet; Don’t react with taste buds the same way
A STARCH
B GLYCOGEN
A STARCH
- Glucose storage polysaccharide in humans and animals
- Referred as ANIMAL STARCH
- Liver cells and muscle cells are the storage sites for glycogen in humans
A STARCH
B GLYCOGEN
B GLYCOGEN
- Is the METABOLIC PATHWAY BY WHICH GLUCOSE IS CONVERTED INTO 2 MOLECULES OF PYRUVATE, a chemical energy in the form of ATP is produced, and NADH-reduced coenzyme produced.
Conversion of glucose to pyruvate is an oxidation process in which NO MOLECULAR OXYGEN IS UTILIZED
GLYCOLYSIS
metabolic pathways in which molecular oxygen is not a participant (GLYCOLYSIS is an anaerobic pathway)
ANAEROBIC PATHWAY
pathways that require molecular
oxygen
AEROBIC PATHWAY
breakdown of glucose into pyruvate or
lactate
A Gluconeogenesis
B Glycogenesis
C Glycolysis
D Glycogenolysis
C Glycolysis
breakdown of glycogen to glucose
A Gluconeogenesis
B Glycogenesis
C Glycolysis
D Glycogenolysis
D Glycogenolysis
formation of glucose-6-phosphate from
non-carbohydrate sources
A Gluconeogenesis
B Glycogenesis
C Glycolysis
D Glycogenolysis
A Gluconeogenesis
conversion of glucose to glycogen for
storage
A Gluconeogenesis
B Glycogenesis
C Glycolysis
D Glycogenolysis
B Glycogenesis
decomposition/breakdown of fat
A Lipolysis
B Lipogenesis
A Lipolysis
synthesis of fatty acids from nonlipid
precursors
A Lipolysis
B Lipogenesis
B Lipogenesis
CARBOHYDRATES range from simple sugars which are basically RING shaped MOLECULES THAT CONTAIN CARBON, OXYGEN AND HYDROGEN, may come alone or in pairs, and can be complex carbohydrates and may connect together to form long chains
T OR F?
TRUE
the OH group of one mono will link with the H of another mono forming H2O or the water molecule
GLYCOSIDIC BONDING
