L01 Primary and Secondary metabolites
-In this lecture we’ll talk about the differentiation between Primary and
Secondary metabolites, and understand the photosynthesis Process.
-There are three major criteria that are important for photosynthesis process:
1.water : generally plant take water by the roots from the soil.
2.energy : from the sun (plants convert sunlight energy to chemical energy
such as; ATP , NADPH ) so moving of electron from ground state to excited
state.
3.Chlorophyll : the most important thing (plants must have Chlorophyll inorder to do Photosynthesis.
*So, that’s mean all plants on earth that simply having Chlorophyll ;they must
go through photosynthesis whether higher or lower plants.
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L01 Primary and Secondary metabolites
-Photosynthesis :
Glucose : (C6H12O6)
-is a monosaccharide carbohydrate, carbohydrate : are compound containing
(Carbon , Oxygen , Hydrogen) . and their ratio of Oxygen is the same ratio of
water as you see in the equation above
6H2O ----<(C6H12O6) .
-it’s Hexose ---< has 6 carbon atom.
Aldose ----< if we have an open chain of glucose.----<
-we have 6 mol of glucose :
-5mol go to krebs cycle
-1mol deposit in plant in form of starch
- the most important and abundant sugar.
-Source of energy.
-it’s the Primary product of photosynthesis.
**so we called it Primary Metabolite (Primary Product).
Primary Metabolite : meaning that all plants on the earth must produce sugar as
first product . and it’s also mean Universal Product (any plant has ability to
produce sugar(glucose) , so universal Products are NOT restricted to any Generic
or species or Family .
Note : we can classify plant by: 1.generic 2.species 3.family.
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L01 Primary and Secondary metabolites
-In certain Plant Glucose commonly known as grape sugar.(means that glucose is
very abundant )
Other plants may produce sugar in very small amount.
so GLUCOSE : Primary product , Primary metabolites , Universal product , grape
sugar.
**Glucose and Starch :
-Glucose store in plants as form of starch .
-Starch : polysaccharide consist of glucose , mainly found in bread , rice , potato ,
corn and barely )‫ (الشعير‬.
-Starch composed of two polysaccharide :
1.Amylose : -Linear chain
-the bonding involve (1-<4) glycoside linkage .
2.Amylopectin : - Branched Chain
-the bonding involve (1-<6( glycoside linkage at branch point.
-so starch go Hydrolysis to give glucose by β amylase enzyme.
β amylase
Starch ---------------------------------------< glucose
-so, people who suffer from diabetes should pay attention when eating food
contain high amount of starch like potato , rice ,bread ,,,,etc.
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L01 Primary and Secondary metabolites
Fructose :
-known as fruit sugar.
-its formed from glucose
Glucose ----<modification-----<fructose so :
-its NOT immediate product
-fructose is similar structure of glucose , its Hexose , but , its Ketose NOT Aldose.
**in our body to convert glucose to glycogen its required insulin , but , fructose
doesn’t required insulin.
 Important of Carbohydrate (mainly glucose as monosaccharide):
1.source of energy in our daily food.
2.in Medicine : glucose is not exactly used as medication , we use Dextrose
(simple sugar chemically identical to glucose ) , used when oral feeding is not
possible , because Dextrose administered as IV Injection .
*plant such as beet , sugar cane , barely .. they like to have a disaccharide
carbohydrate : sucrose , maltose , lactose(milk sugar).
Cellulose :
-which make the cell wall of plant.
-its chemically identical to starch , mainly consisting sugar glucose , but not
α(1-<4) or α (1-<6) glycoside linkage , its β(1-<6) linkage for this reason
cellulose is more fold and accumulate over each other to keeping the strength
and rigidity of cell wall.
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L01 Primary and Secondary metabolites
-trunk rich in cellulose.
**Glycolysis :
Degradation or splitting of carbohydrate (glucose) into two unit.
Sense ,glucose contain 6 c’s atom so after degradation it will result in 3 c’s atom (
is the simplest Hydrocarbon) known as glycerin.
So Glycerin is poor hydrocarbon , contain of 3’s carbon.
Role of glycerin :
-as laxative (suppository)
-its derivative nitroglycerine as vasodilator.
Lipid :
-goes β oxidation .
-all our fat (lipid , fattyacid , fix oil ….) having an even number of carbon , we
never have an odd number .
Why ??
This due to formation of fatty acid from glucose by glycolysis , plant form pyruvic
acid (3’c) using carbon dioxide and finally form acetic acid . (acetic acid
pawthway). –the Doctor said details not required-so infact acetic acid form from glucose.
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L01 Primary and Secondary metabolites
Know we will talk about secondary metabolites..
2nd Metabolite :
-not directly related to maintain life (not important to living organism) , while 1st
is important to living organism as we said.
-not Universal product.
-restricted to certain generic , species ,family.
-in fact the most important, and what we use in therapy are secondary
metabolites.
Example :
1. Cocaine (cocaine alkaloids) :
Is only found in coca plant m never been detectable or isolated from other plants.
(restricted to this genius )
2. Morphine ( Morphine alkaloids) :
Is only found in poppies somniferum )‫(الخشاش‬
(restricted only to this species)
3. Atropine , Hyoscyamine , Scopolamine :
All these alkaloids are obtained from :
atropa belladonna
or hyoscyamus muticus
or Datura stramonium.
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L01 Primary and Secondary metabolites
All of these are from solanaceae family
(restricted only to this Family)
**back to Photosynthesis :
-in primary metabolites we follow one chart so we expect that always we have a
sugar glucose.
-in secondary metabolites it’s not the same , here we have what we called
biosynthesis )‫(االصطناع الحيوي‬
-Biosynthesis : mean the plant that go biosytheticphoto have different chart ,
every product , every material represent biosynthetic pathway.
-When we talk about acetic acid pathway in lipid and F.A , acetate here known as
precursor , precursor mean that if starting material go abiosynthetic process on
plant for any 1st or 2nd metabolites .
**why plant need a 2nd metabolite ??
-we don’t have critical evident why ,, its Hypothesis .
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