Study Notes On Biology MICRO ORGANISMS

MICRO ORGANISMS

Micro organisms are classified into four major groups. These groups are bacteria, fungi, protozoa and algae. Viruses: They reproduce only inside the cells of the host organisms which may be bacterium, plants or animal. Common cold, influnenza and most coughs are caused by viruses. Serious diseases like polio and chickenpox are also caused by viruses. Micro organisms may be single celled like bacteria, Some algae and protozoa. Multicellular such as algae and fungi. Micro organisms like amoeba can live alone, while fungi and bacteria may live in colonies.

 

Advantages of Micro Organisms

Pasteur discovered fermentation. Making of curd and breed:-milk is turned into curd by bacteria. The bacterium “lactobacillus” promotes the formation of curd. Yeast reproduces rapidly and produces CO2 during respiration. Bubbles of the gas fill the dough and increase its volume. Yeast is used for commercial production of alcohol and wine. For this purpose yeast is grown as natural sugars present in grains like barley, wheat, rice, crushed fruit juice etc. This process of conversion of sugar into alcohol is known as fermentation. Lewis  Pasteur discovered fermentation.

 

Medicinal Use of Micro Organisms

The medicine which kills or stops the growth of diseases causing microorganism is called antibiotics. Streptomycin, tetracycline and erythromycin are some of the commonly known antibiotics. Which are made from fungi and bacteria. Alexander Fleming discovered penicillin. Antibiotics are not effective against cold and flu as these are caused by virus.

 

Vaccine

 

• Edward Jenner discovered the vaccine for small pox.

Harmful Microorganisms

• Disease-causing microorganisms are called pathogens.
• Microbial diseases that can spread from an infected person to a healthy person through air water, food, or physical contact are called communicable diseases. i.e.- cholera, common cold, chicken pox and TB.
• Female anopheles mosquito which carries the parasite of malaria.
• Female aedes mosquito acts as carrier of dengu virus.
• Robert Koch discovered the bacteria (bacillus anthracis) which causes anthrax disease.

 

Common Methods of Preserving Food in our Homes

 

• Chemical method: salt and edible oils are the common chemical generally used.
• Sodium benzoate and sodium metabisulphite are common preservatives. These are also used in the Jams and squashes to check their spoilage.

 

Preservation by sugar :

 

• Sugar reduces the moisture context which inhibits the growth of bacteria which spoil food.
• Use of oil and vinegar prevents spoilage of pickles become bacteria cannot live in such an environment.
• Pasteurized milk : the milk is heated to about 70˚C for 15 to 30 seconds and then suddenly chilled and stored.
• This process was discovered by Louis Pasteur. It is called

 

Short Notes on Vitamins

 

A vitamin is an organic molecule (or related set of molecules) that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrients cannot be synthesized in the organism, either at all or not in enough quantities, and therefore must be obtained through the diet. Vitamin C can be synthesized by some species but not by others; it is not a vitamin in the first instance but is in the second. The term vitamin does not include the three other groups of essential nutrients: minerals, essential fatty acids, and essential amino acids. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, vitamin E consists of four tocopherols and four tocotrienols. The thirteen vitamins required by human metabolism are: vitamin A (retinols and carotenoids), vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folic acid or folate), vitamin B12 (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (quinones).

The term vitamin is derived from the word Vitamin, coined in 1912 by Polish biochemist Casimir Funk, who isolated a complex of micronutrients essential to life, all of which he presumed to be amines. When this presumption was later determined not to be true, the “e” was dropped from the name. All vitamins were discovered (identified) between 1913 and 1948.

VITAMIN K (PHYLLOQUINONE)

SOURCE

 

Green leafy vegetables, soya beans. The human body can also produce Vitamin K through germs in the colon(part of small intestine).

FUNCTION

 

• Helps blood clotting, prevent over bleeding
• Maintains health of the liver

 

SYMPTOMS OF DEFICIENCY

 

Uncontrol bleeding from wounds due to clotting difficulty

SYMPTOMS OF EXCESS

Can lead to liver damage

VITAMIN E (TOCOPHEROL)=BEAUTY VITAMIN

 

It is also known as Antisterility Vitamin.

SOURCE

 

Green leafy vegetables, whole-wheat cereals, nuts, sprouts, egg yolk

FUNCTION

 

• Maintains normal conditions of cells, and healthy skin and tissues
• Protects red blood cells
• Antioxidation
• Enhance immunity

SYMPTOMS OF DEFICIENCY

New born infants: haemolytic anaemia

Adults: weakness

SYMPTOMS OF EXCESS

• Low thyroxine level
• Fertility Desease
• Headache, dizziness, fatigue
• Stomach discomfort, poor appetite

VITAMIN D (CALCIFEROL)=(SUNHINE VITAMIN)

SOURCE

Egg yolk, liver, cod liver oil, fish. Our skin also produces Vitamin D when exposed to sunlight.

FUNCTION

• Helps body absorb and utilize calcium and phosphorus, so as to maintain bones, teeth and brain healthy
• Maintains normal calcium level in blood

SYMPTOMS OF DEFICIENCY

 

Children: rickets

Adults: Osteomalacia, Osteoporosis

SYMPTOMS OF EXCESS

 

• Calcified cartilage
• High calcium level in the blood causes abnormal heart beat and damage to organs such as kidneys
• Vomiting, diarrhea
• Sore eyes
• Itchy skin

VITAMIN A (RETINOL)

 

SOURCE

Dairy products, cod liver oil,liver, dark green and yellow vegetables and fruits

FUNCTION

 

• Maintain eye health
• Promotes growth and development, maintains healthy bones and teeth
• Enhances the protection and regeneration of cells and mucous membrane
• Maintains healthy respiratory and intestinal tracts
• Maintain healthy hair, nails and skin

SYMPTOMS OF DEFICIENCY

 

• Night blindness, dry eyes
• Dry skin
• Stomach discomfort
• Poor growth
• Weak bones and teeth

SYMPTOMS OF EXCESS

 

• Dry, scaly, peeling, and itchy skin, rash
• Hair loss
• Poor appetite, fatigue
• Vomiting, stomach discomfort
• Liver injury
• Headache, bone pain
• Nervousness, irritability

VITAMIN B

VITAMIN B1 (THYMINE)

SOURCE

sprouts, yeast

Desease

Beri-beri

VITAMIN B2 (RYBOFLABIN)

SOURCE

sprout, present in cow’s milk(yellowish)

Desease

Cheilosis, ulceration

VITAMIN B6 (PYRIDOXINE)

FUNCTION

It is responsible for rememeber dreams.

SYMPTOMS OF DEFICIENCY

Anaemia

Nervousness, insomnia, depression

Muscle cramps

VITAMIN C (ASCORBIC ACID)

SOURCE

Citrus fruits (orange, grapefruit, lemon), strawberry, black current, kiwi fruit, tomato, green leafy vegetables, green pepper

FUNCTION

 

• Helps synthesize collagen; promotes the growth and repair of cells, gum, teeth, blood vessels and bones
• Helps healing after operation and injury
• Helps calcium and iron absorption
• Enhances immunity

SYMPTOMS OF DEFICIENCY

• Scurvy
• Gum
• inflammation and bleeding, fall of teeth
• Susceptibility to skin bleeding, burst of capillary vessels
• Weakness, fatigue
• Bone pain, swollen and aching joints

SYMPTOMS OF EXCESS

• Abdominal pain
• Diarrhea
• Kidney stone

In smokers and drinkers vitamin C is absent.

TYPES OF VITAMINS:

 

Vitamin	Chemical Name	Food Sources	Deficiency Diseases
A	Retinol	Milk, eggs, fish, butter, cheese and liver.	Night blindness, Skin dryness.
B1	Thiamine	Legumes, whole grain, nuts.	Beri-beri.
B2	Riboflavin	Egg, milk, cheese, nuts, bread products.	Inflammation of tongue, sores in the corners of the mouth.
B3	Niacin or Nicotinic acid	Meat, fish, pea nuts, whole grain.	Skin disease, diarrhoea, depression, dementia.
B5	Pantothenic acid	Eggs, liver, dairy products.	Fatigue, muscle cramp. Pellagra
B6	Pyridoxine	Organ meats, cereals, corn.	Anaemia, kidney stones, nausea, depression.
B12	Cyanocobalamin	Meat, fish.	pale skin, constipation, fatigue.
C	Ascorbic acid	Oranges, tomatoes, sweet and white potatoes.	Scurvy, anaemia, ability to fight infections decreases.
D	Calciferol	Direct sunlight, fish oils, eggs.	Rickets, osteomalacia.
E	Tocopherol	Vegetable oils, olives, tomatoes, almonds, meat, eggs.	Neurological problems, problems of reproductive system.