Compound Found in a Plant Cell | Plant Physiology

This article throws light upon the five major types of compound found in a plant cell. The compounds are: 1. Carbohydrate 2. Protein 3. Nucleic Acid 4. Enzymes 5. Vitamins.

Plant Cell Compound: Type # 1.

Carbohydrate:

The general formula of carbohydrate is (CH₂OH)ⁿ.

Types of carbohydrate:

(i) Monosaccharide

(ii) Oligosaccharide

(iii) Polysaccharide

(i) Monosaccharide (C₆H₂O₆): 

I. Mostly found in grape, fruits and honey.

II. It contains 3-9 carbon atoms,

III. Monosaccharide types:

(a) Glucose:

(i) Also called as dextrose

(ii) It is corn sugar

(b) Fructose:

(i) It is fruit sugar

(c) Galactose

(d) Mannose

(ii) Oligosaccharide:

I. It consists of 2-6 monosaccharide’s unit’s

II. Oligosaccharide types:

(a) Disaccharides:

(i) it has 2 monosaccharide’s

(ii) Contains Sucrose, Maltose, Lactose and Cellobiose

(b) Trisaccharides:

(i) it has 3 monosaccharide’s

(ii) Contains Raffinose

(c) Tetrasacharides:

(i) it has 4 monosaccharide’s

(ii) Contains Stachyose

III. Disaccharides:

(a) Sucrose:

(i) It outcomes from a 1, 2 glycosidec linkage between a glucose and b pructose.

(ii) It is non reducing sugar.

(b) Maltose:

(i) Consists of two units of glucose linked together with a 1, 4- linkage.

(ii) It is a reducing sugar.

(c) Cellobiosis:

(i) Consists of two units of glucose linked together with b 1,4- linkage.

(ii) It is a reducing sugar.

(d) Lactose: Glucose + Galactose

(i) Consists of one molecules of each of b, D-glucose and b, D-galactose linked together with p 1,4-glucosidec linkage.

(v) Stachyose:

(i) Consists of one molecules of each glucose and fructose and 2 molecules of galactose.

IV. Trisaccharides:

It is simple sugar, derived from hydrolysis of oligo-polysaccharides having 3-9 carbon atoms.

(a) Aldoses:

i. Aldoses are sugar with terminal CHO aldehyde group aldotriose-glyceraldehyde.

e.g. Aldotetrose (Erythrpse, Trehlose)

ii. Aldopentose (Arabinose, Ribose, Deoxy-ribose)

iii. Aldohexose (Glucose, Galactose, Mannose)

(b) Ketose:

i. Aldoses are with >C=0 group aldotriose-glyceraldehyde.

e.g. Ketoriose (Dihydrose and Acetone – a simple keto sugar)

ii. Ketohexose (Fructose – the sweetest sugar)

(c) Polysaccharides:

i. Consists of as many as 10,000 monosaccharide’s.

ii. Polysaccharide types:

(a) Storage polysaccharides:

e.g. Amylose – un-branched chain of glucose units joined together by a 1,4 glycosidic linkage into non linear helical chain. Amylopectine – highly branched chain joined together with an a 1, 4 linkage and at ends with a 1, 6 linkage

(b) Glycogen: Presence in Animal cells.

(c) Structural polysaccharides:

(i) Cellulose-polymer of glucose

(ii) Hemicellulose – polymer of L-arabionose

(iii) Pectin – polymer of Galaturonic acid, normally present in cell wall as calcium pectate.

Plant Cell Compound: Type #  2.

Protein:

I. Protein is made from Greek word “Proteios” means Primary.

II. Proteins are the polymers of amino acid.

III. Protein is discovered by Berzeus.

Classification of proteins:

(a) Simple protein – protein that contains only amino acid.

(b) Conjugated protein-protein that contains non amino acid components with addition to amino acid. These additional factors are called Prosthetic group.

Examples:

(a) Nucleo proteins – Nucleic acid and protein – chromosomes

(b) Glycoprotein – Protein and sugar units

(c) Lipoproteins – Protein and lipids

(d) Metalloproteins – Metals and proteins

Plant Cell Compound: Type #  3.

Nucleic Acid:

Classes

I. DNA – Deoxyribose

II. RNA-Ribose

Nucleoside = Sugar (Ribose/Deoxyribose) + Nitrogenous base

Nucleotide = Nucleoside + phosphate group

Bacteriophages – single stranded DNA

Functions:

(a) Transfer of genetic traits from one generation to another generations.

(b) Control in formation of enzymes and synthesis of protein.

Types of Nases:

(a) Purines: Adenine, Guanine (AG)

(b) Pyrimidines: Thymine, Cytocine, Uracil (CUT)

Ribo-nucleic Acid (RNA): 

(a) m-RNA (Messenger RNA) – 5% carries the message from genes (DNA), Serves as the template for protein synthesis.

(b) t-RNA (Transfer RNA) – Transfer amino acids from cytoplasm to Ribosome, ‘ attaches to a specific amino acid and pairs it to the appropriate codon on the m-RNA.

(c) r-RNA (Ribosomal RNA) -It makes up the ribosome, Ribosome is the site at which protein synthesis occurs.

Plant Cell Compound: Type # 4.

Enzymes:

I. Enzyme is a Greek word which means ‘in Leaven’.

II. Enzymes are the polymers of amino acid and acts as a catalyst.

III. The term ‘Enzyme’ was given by W. Kuhne in 1867.

IV. Enzyme is discovered by Buckner.

Characteristics of an Enzyme:

(a) Specific, protinacious, colloidal nature, sensitive to temperature.

(b) Enzymes do flat change the equilibrium level, but quickens it.

Classification of Enzymes:

(a) Hydrolytic enzymes – reacting with water molecules

(b) Oxidizing enzymes – reacting with oxygen

Terminology:

(a) Holo enzyme – Apoenzyme + Prosthetic group

(b) Apo enzyme – Enzyme without Prosthetic group

(c) Allosteric enzyme – Regulatory enzyme have more than one polypeptide

(d) Isozyme – Different enzymes which catalyze the same reaction in different tissue

(e) Ribozyme – They catalyzing RNA with enzymatic activity. They are only Non-proteinious enzyme

(f) Active site – Site responsible for catalysis of molecules

(g) Regulatory site – The site other than catalytic site

(h) Zymase is the 1^st enzyme which was discovered by yeast.

(i) Pepsin and Trypsin is the auto-catalysis enzyme

Plant Cell Compound: Type # 5.

Vitamins:

(a) Vitamin was introduced /discovered by Funk in 1911.

(b) Vitamin acts as a catalyst.

(c) Total well defined vitamins are 13.

Classification of Vitamins:

(a) Water soluble vitamins – Vit B complex (B₁, B₂, B₁₂), By Vit. C

(b) Fat soluble vitamins – Vit A, D, E and K