Thursday 24 December 2020

Sasha Sloan - Is it just me (lyrics)

Tuesday 7 July 2020

NOTES ON CHROMOSOMES

Notes on Chromosomes

Chromosomes

• These are rod or ribbon-shaped, dark stained bodies within the cell.
• That contains the cell’s genetic material.
• Only seen using basic dye under a light microscope.

• Chromosome term is a combination of two Greek words, Chroma and Soma.
• Chroma – Colour
• Soma – Body
• Because of strongly stained by some dyes.
• In prokaryotes the Chromosomes are circles of DNA.
• While linear and complex structural chromosomes are present in eukaryotes.

Named by

• Heinrich Wilhelm Gottfried Von Waldeyer – Hartz in 1888.

• He gave this name to the structure that appears during the process of cell division(Reproduction).

Chromosomes are clearly visible as distinct bodies during the stage of cell division only and their number can be counted with relative ease only during mitotic metaphase.

Chromosome number

• Can describe in two parts as
1. Somatic chromosome number
2. Gemetic chromosome number

1. Somatic chromosome number

• These are the number of chromosomes found in somatic cells. E.g. Tissues and Meristemetic cells.
• These are represented as 2n.
• 44 are autosomal chromosomes.

2. Gemetic chromosome number

• The number of chromosomes found in germ cells. E.g. Ovum and Sperms.
• These are represented by n.
• 2 (X and Y) are sex chromosomes.

Chromosomal Morphology

• Composition of chromosomes

1. Negatively charged DNA

- It’s a coiled DNA that contains genes, regulatory elements and nucleotide sequences.
- Chromosomes are composed of 10,000 to 1,000,000,000 nucleotides.
- The DNA that presents in a chromosome is approximately long as 8.5 centimetres.

2. Positively charged Histone Proteins

• Histone proteins are 80% of the chromosomal proteins.
• Molecular weight range from 10,000 to 30,000 D.
• Types—H1, H2a, H2b, H3, H4
• H1—Lysine rich
• H2a, H2b—slightly Lysine rich
• H3, H4 – Arginine rich
• These all completely devoid to tryptophan.

Structural features of chromosomes

• Chromatids
• Centromere
• Telomere
• Secondary Constrictions
• Satellite Chromosomes
• Chromomere

Chromatid

• Metaphase Chromosomes are to be longitudinally divided into two identical parts.
• These two parts appear like two identical arms and known as two sister chromatids and individually called Chromatids.
• And these sister chromatids are appeared to be joined together at the centromere.
• These separate only at the anaphase stage and move to the opposite poles.

Centromere

• The region where two sister chromatids are appeared to be jointed or held together.
• Divide chromosomes into two equal or unequal sections or arms.
• If divide into two unequal parts then
o Short arms represented by “p”.
o Long arms represented by “q”.
• Also known as primary constriction region.

Primary Constriction region - The narrow region in the chromosome arm.

• In anaphase the centromere and spindle fibres attached together by a protein called KINETOCHORE.
• Location of centromere in chromosome provide specific shape and describe the location of genes.

Telomere

• Ends of chromatids called Telomeres.
• These are highly stable.
• Not easily fused with the telomere of other chromosomes.
• Fusion is very rare if telomere is broken.
• Do not have any structural features under a light microscope.
• These are the highly condensed form of 300 A° Chromatin fibres.

Secondary Constrictions

• These are the additional constrictions to the centromere.
• Generally located near the short arm of the chromosome.
• Also called NOR(Nucleolar Organizing Region).

Satellite Chromosomes

• The region between the secondary constriction and the telomere called SATELLITE.
• The chromosomes having satellite called Satellite Chromosomes.
• These also known as Sat Chromosomes and NOC(Nucleolar Organism Chromosome).

Chromomere

• Appear like small beads like structures during the Pachytene stage of the first prophase of meiosis I.

Types of Chromosomes

• On the basis of the location of Centromere in Chromosomes

1. Submetacentric – Centromere is located at one side of the centre of chromosomes. In this type chromosome is J shaped at the metaphase stage.
2. Metacentric— Centromere is present in the centre of Chromosomes. In this type of chromosome is V-shaped at the metaphase stage.
3. Acrocentric– Centromere is located close to the end of the chromatids. A chromosome is rod-shaped at the metaphase stage.
4. Telocentric – Centromere appeared to located at the end of a chromosome.Chromosomes are rod-shaped at the metaphase stage.

• On the basis of the number of Centromere in Chromosomes

1. Acentric – Without any centromere and it is very rare.
2. Monocentric – Having one centromere and this type is very common in cells.
3. Diacentric – Having two centromeres.

Acentric and dicentric chromosomes are produced due to chromosomal aberrations such as deletion, duplication, translocation or breakage.

• Significance of Chromosomes

o The organ of heredity.
o Form link between two generations.
o Maintain and replicate the genetic information.
o Ideograms show the Bending Patterns and describe the location of genes.
o Karyotyping of chromosomes shows chromosomal aberrations, cellular functions, taxonomic relationship and to gather the information about the evolutionary events.

Saturday 4 July 2020

APPLICATIONS OF ENZYMES

ENZYMES

- A substance produced by living organism which acts as a biological catalyst to bring about a specific biochemical reaction.

- These are the protein that speed up the reaction.

- Perform specific significance reaction essential for the reaction process with ensuring the quality of product.

- Used in food production on basis of purpose and need.

- An enzyme can convert a specific set of reactants into specific products.

CLASSIFIED AS

1. Oxidoreductase
2. Transferase
3. Hydrolases
4. Lyases
5. Isomerase
6. Ligase

SOURCES OF ENZYMES

1. Animals
2. Plants
3. Microbes

There are two parts of enzymes.
1. Core enzyme – protein part
2. Co factor – non protein part
Both part present in enzyme called HOLOENZYME. Enzymes generally increase the rate of reaction without causing any change in reaction.

Enzyme + substrate → enzyme + product

These are substrate specific, product specific, group specific and earlier named depend upon specificity. Now named by IUPAC ( INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY)

APPLICATIONS OF ENZYMES IN DIFFERENT FIELDS

A. FOOD

-ENZYMES ARE USED IN FOOD INDUSTRY FOR:- - Food modification
- improving nutrition quality
- Extraction
- brewing
- Filtration
- Fermentation
- APPLICATIONS OF ENZYMES IN FOOD INDUSTRY
Enzymes playing an important role in food production.
- bakery products
- chocolate syrups and candies
- infant food
- cheese and dairy products
- egg products
- fruit juices
- Alcoholic beverages
- sweeteners
- Liquid coffee
- meat tenderizing
- Flavour development
- chill proofing of bear

SOURCES OF FOOD ENZYMES:-

PLANTS -- amylase, glucanase, papain, lipoxygenase, chymopapain
ANIMAL -- trypsin, chymotrypsin, pepsin, renin, catalase, amylase, pancreatic lipase.
MICROORGANISMS – amylase, glucose isomerase, cellulose, invertase, catalase, lactase.

1. In the baking of bread--Used enzymes – α and β amylase, protease
- used for appearance, freshness, taste, flavour, colour
In the preliminary process, the wheat flour mixed with water and yeast. Wheat flour contains starch and protein. Starch consist D-glucose linked by α-1,4 glycosidic bonds and α-1,6 bonds at branching points. The enzymes α and β amylase are present in the wheat flour cleave the α-1,4bond and produce the glucose and maltose & some oligosaccharides. Glucose and maltose are metabolized by yeast and produce carbon dioxide and make wheat flour ready for baking. Bakery products like biscuits, crackers, cookies, bread dough.

2. Invert suger -- Used enzyme – β-fructofuranosidase known as invertase.
A mixture of glucose and fructose are produced from sucrose by action of invertase. Invert sugar may be produced from glucose by the action of glucose isomerase an enzyme identical to xylose isomerase.
- These obtained from Saccharomyces cerevisiae.
- Also known as sucrase.
- Examples-- Candies with soft centres, Chocolate covered cherries.

3.Beverage industry - Products like wine, beer, soy sauce, fruit juices are produced by fermentation process.
used enzymes -- cellulase, hemicellulose, amylase, glucanase, lipase, decarboxylase are used for liquefaction, clarification.
The clarification of cider,wines and fruit juices achieved by treatment with fungal pectinases. These pectinases are the group of enzymes including polygalacturonases which break the main chains of pectin, and pactinesterases hydrolyses the methyl esters. Their action releases the trapped particles and allow them to flocculate. The pectin of fruits and vegetables play an important role in jam making. These enzymes are decreasing the process capacity but enhance the flavor, color, texture of juice.
- Pectinase and amylase increase the juice production, volume, and color extraction.
- Pectinase used in wine production for preventing haze forming and to get clear solution. Used during fermentation and clarification.
- Cellulase, hemicellulose, pectinase – are used in coffee industry.

- Glucanase, cellulase – are used to break down the cell wall of tea leaf.

4. Dairy industry - Milk is the chief ingredient in dairy products.
Products like yoghurt, buttermilk, cheese, buttercream all are produced by fermentation process.
- ENZYMES -- protease, lipases, lactases, renin.
- LACTOSE FREE DAIRY PRODUCTS:- In these products, the milk sugar of milk, yoghurt, ice cream, cheese are converted into digestable sugar, glucose, galactose by the enzyme lactase.
- CHEESE PRODUCTION- This involves the conversion of milk protein κ- casein to para- casein by hydrolysis by enzyme chymosin.

5. Meat tenderizer -- used enzymes --Papain, bromelain, ficin enzyme is used for meat tenderization.
--aslo used in brewing industry to prevent chill hazes, caused by precipitation of complexes of proteins and tannin at low temperature.
- Transglutaminase used to introduce gelation to meat products.

Enzymes are important in the foodstuff in monitoring the processing and storage of food and as a means of detecting contamination by micro-organisms.

- Palatase - Enhance cheese flavour
- Lipozyme - Interesterification of vegetable oil
- Lipopane - Emulsifier

B. MEDICINE AND DIAGNOSIS

Assays of some of the enzymes present in blood plasma and serum are carried out in most clinical chemistry laboratories and these play an important role in diagnosis. Due to there catalytic activity, these enzymes are used in various ways. Some important enzymes are used in medicine for killing disease causing microbes, promoting wound healing, diagnosing certain diseases.

1. IN CASE OF SERUM ENZYME
- If cell of particular tissue affected by a disease then
- the cell content leak out into the blood stream
- and this content contain the enzyme associated with those cells
- their rate found increased in blood plasma
- So, plasma enzymes are used to identify the location of damaged cells.

a. LACTATE DEHYDROGENASE (LDH)
- Present in liver and skeletal muscle
- when show higher concentration in blood
- indicate damage to the liver cells.(60-200 IU/L)

b. ASPARTATE AMINOTRANSFERASE
- Present in heart and liver cells.(0-45 IU/L)
- when show higher concentration in blood
- indicate damage to the liver cells and heart tissues.

c. ALANINE AMINOTRANSFERASE
- Present in higher concentration in liver than elsewhere.
- And when show higher concentration in blood
- show viral hepatitis and toxic liver necrosis.(0-41 IU/L)

d. ALKALINE PHOSPHATASE
-Present in kidney.( 3-13 KA UNIT/100ml)

e.CREATINE KINASE
- Present in heart tissue and skeletal muscle and brain tissues.(10-50 IU/L)

f.TRYPSIN(115-350 IU/L), TRIACYLGLYCEROL LIPASE(<150 IU/L), α-AMYLASE(30-110 IU/L)
- Are produced in the pancreas and when found higher concentration in blood serum show certain damage to the pancreas or acute pancreatitis.

g. ACID PHOSPHATASE
- Found in prostate gland, also some amount in liver, red cells, platelets and bones.
When found in plasma indicate the prostatic carcinoma.

2. ENZYME USED IN IMMUNOASSAYS
Used as alternative of radioisotopes as markers in the immunoassays for determination of a variety of proteins and hormones.

- In these enzymes acts as markers and replaced by isotopes
- because these are non- hazardous to health
- and can be detected by techniques in the body.

Examples of enzyme immunoassay procedures are
1. Enzyme-linked immunosorbent assay (ELISA)
2. Enzyme Multiplied immunoassay test (EMIT)

A. ELISA
Elisa is highly sensitive assay that can be used to detect either antigen or antibody.
- Applications of ELISA include diagnosis for noninfectious diseases involving hormones, serum components, and autoimmune diseases, infectious diseases caused by bacteria, viral or parasites.
- The enzymes used in ELISA are horseradish peroxidase, alkaline phosphatase and β galactosidase.

B. EMIT
In EMIT the activity of malate dehydrogenase used for detection of thyroxine by enzyme labelled immunoassay.

3. ANALYTICAL USE

- Glucose oxidase for diagnosis of DIABETES by measuring the amount of glucose in blood and urine. The enzyme catalyses the reaction between glucose and oxygen to form gluconic acid . This gluconic acid detected by biosensors and change in colour.

4.MANIPULATIVE ENZYMES:-

- These are the enzymes that have improved properties to improve health.

5.THERAPEUTIC USES:-

- Enzymes can be used individually or along with other drugs or treatments.
- Enzymes can also be used as supplements for enzymes deficiencies.
- Prolactazyme treats lactose intolerance.
- Collagenase treats skin ulcer.
- Asparaginase used to treat leukaemia.
- Streptokinase administered to the patients immediately after heart attacks.

6. INDUSTRIAL USES:-
- Penicillin acylase and glucose isomerase are mostly used enzymes in the medicine life.
- Both are used in the production of semi-synthetic penicillin and fructose syrup.

C. ENZYMES IN TEXTILES INDUSTRY

Enzymes are used in chemical and many other industries because of there extremely specific catalytic activity. Very few enzymes are used for this purpose because of low stability at high temperature. With advanced protein engineering which is an active area of research produce enzymes which have novel properties.

ENZYMES ARE USED IN TEXTILE BECAUSE

- Very efficient catalyst, a high degree of specificity
- environment-friendly, non-toxic, non-flammable sustainability
- fully biodegradable, can operate at mild condition, catalyze broad spectrum of reactions, fewer byproducts, can be reused
- low energy consumption
- can be produced in unlimited quantity

A. DRY CLEANING
The enzyme lipase, protease, amylase in the presence of organic sample butoxy propoxypropanol used to clean the fabric.

B. DENIN WASHING
- used enzymes are protease and cellulase
When fabric show back staining with cellulase enzyme then enzyme protease added for overcoming this problem at pH 6-10 and at temperature 30-60°C

C. BIOPOLISHING
It is a finishing process that improves the fabric quality by giving it a soft feel and reducing the fuzziness and pilling property of cellulosic fibres. The objective is to eliminate microfibrils of cotton through the action of cellulase enzyme.
The cellulosic enzyme contains three enzymes
1.exo-β(1,4)glucanase
2 .endo-β(1,4)glucanase
3 .β-glucanase.
Endo-β(1,4)glucanase – Break down the cellulosic fibres, by breaking the polymer chain and forming two new ends.
Exoglucanase—The newly formed two ends are attacked by exoglucanase. Results in the formation of Cellobiose, which is split into two glucose molecules by β glucosidase. Thus the combined action of endo and exoglucanase partially hydrolyses the cellulose chains. The fibres are consequently weakened and can be separated from fabric by mechanical stress.

D. BIO- BLEACHING
- Enzymes can also be used in the bleaching process.
-Glucoseoxidases are flavoproteins with a Flavin – adenine dinucleotide active site.
-The enzyme is highly specific for B-D-glucose and catalyses the glucose for hydrogen peroxide generation at pH 4.5 -7 and temperature of around 40 degrees C.
-If peroxide for textile bleaching has to be generated by glucose oxidases, slightly acidic to the neutral conditions and far lower temperature are required to avoid deactivation of the enzymes. The bleaching effect of the peroxide under these conditions is, however, insignificant.

E.DETERGENTS:-
-Enzymes have been used in many kinds of cleaners for over 30 decades, since they were first presented by NOVOZYMES. Traditional use of minerals in cleansing cleaners involved those that lower protein causing spots, such as those found in lawn spots, red drinks. Lipases are another useful class of minerals that can be used to reduce fat spots and clean oil barriers or other fat-based cleaning programs.
-Currently, a popular area of research is the research of minerals that can withstand or even have higher activities, in hot and cold weather. The look for thermotolerant and cryotolerant minerals has spanned the planet. These minerals are especially suitable for enhancing cleansing procedures in hot water periods and at low conditions.

F.LIQUID ALIVE ENZYME DIGESTANTS:-
These enzymes are used as stain remover.
Removers-- Grease, wine, iodine, cosmetics, dirt, protein, ink, blood, oil-based stain.
Use on -- Carpets, leather, vinyl, synthetics, textiles.

G.BIOSCOURING
- Bioscouring is the process by which alkaline stable pectinase is used to remove selectively pectin and waxes from the seed coat fragments called motes.
- Pectinase and cellulase are used for this purpose.
- Pectinase can destroy the cutinize structure by digesting the inner layer of pectin in the cuticle of cotton. On the other hand, cellulose can destroy the cuticle structure by digesting the primary wall cellulose immediately under the cuticle of cotton.
- The cellulose breaks the linkage from the cellulose side and the pectin is from the cuticle side.