Restriction Endonucleases

The Restriction endonucleases recognizes a specific base sequence of four to eight bases in double-stranded DNA and cleaves both strands of the duplex.

There are known type of restriction endonucleases : type I,II and III. Type II enzymes are frequently used in the rDNA technology. Type I and type III are not use because these type enzymes cleaves the DNA far from the recognition sites.

The Restriction endonuclease recognizes particular specific sequences are 4 to 6 nucleotides recognize by the type II enzymes because these enzymes only cleave at this site. The palindrome sequence is “Two-fold symmetry” as shown above video.

Restriction Endonuclease

Lecture Video : Metabolism Part III

Lecture Series on BioChemistry I by Prof.S.Dasgupta, Dept of Chemistry, IIT Kharagpur.

Intermediary Metabolism III

See this links:

Metabolism Part I

Metabolism Part II

(Links will update soon)

Lecture Video Metabolism II

Intermediary Metabolism II

Lecture Video Intermediary Metabolism

Metabolism (pronounced: muh-tah-buh-lih-zum) is a collection of chemical reactions that takes place in the body's cells. Metabolism converts the fuel in the food we eat into the energy needed to power everything we do, from moving to thinking to growing. Specific proteins in the body control the chemical reactions of metabolism, and each chemical reaction is coordinated with other body functions. In fact, thousands of metabolic reactions happen at the same time — all regulated by the body — to keep our cells healthy and working.

Metabolism is a constant process that begins when we're conceived and ends when we die. It is a vital process for all life forms — not just humans. If metabolism stops, living things die.

Here's an example of how the process of metabolism works in humans — and it begins with plants. First, a green plant takes in energy from sunlight. The plant uses this energy and a molecule called chlorophyll (which gives plants their green colour) to build sugars from water and carbon dioxide. This process is called photosynthesis, and you probably learned about it in biology class.

When people and animals eat the plants (or, if they're carnivores, they eat animals that have eaten the plants), they take in this energy (in the form of sugar), along with other vital cell-building chemicals. The body's next step is to break the sugar down so that the energy released can be distributed to, and used as fuel by, the body's cells.

After food is eaten, molecules in the digestive system called enzymes break proteins down into amino acids, fats into fatty acids, and carbohydrates into simple sugars (e.g., glucose). In addition to sugar, both amino acids and fatty acids can be used as energy sources by the body when needed. These compounds are absorbed into the blood, which transports them to the cells. After they enter the cells, other enzymes act to speed up or regulate the chemical reactions involved with "metabolizing" these compounds. During these processes, the energy from these compounds can be released for use by the body or stored in body tissues, especially the liver, muscles, and body fat.

See the Lecture Video

 

Intermediary Metabolism

 

 

 

Lecture Series on BioChemistry I by Prof.S.Dasgupta, Dept of Chemistry, IIT Kharagpur.

List of Biomolecules video lectures

A biomolecule is a chemical molecule that naturally occurs in living organisms. Biomolecules consist primarily of carbon and hydrogen, along with nitrogen, oxygen, phosphorus and sulfur. Other elements sometimes are incorporated but are much less common.

This is very useful videos.

1. Amino Acids

Amino acids part I

Amino acids Part II

2. Proteins

Proteins Part I

Protein Part II

Protein Part III

Protein Part IV

3. Nucleic Acids

Nucleic Acids Part I

Nucleic Acids Part II

Nucleic Acids Part III

4. Carbohydrates

Carbohydrates Part I

Carbohydrates Part II

5. Enzymology

Enzymes I : Basics

Enzymes II

Enzymes III : Enzymes as Biocatalysts

          6.Lipids and Membranes
          Lipids and Membranes 1
          Lipids and Membranes II
          Membrane Transport


         7. Vitamins and Coenzyme

            Vitamins and Coenzymes 1
            Vitamins and Coenzymes II

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Video lecture : Lipids and Membranes 1

The lipids are important constituents of the diet because of their high energy value and also because of the fat-soluble vitamins and the essential fatty acids found with the fat of the natural foodstuffs. In the body, the fats serve as efficient source of energy which is stored in the adipose tissues.

Lipids are not generally classed as macromolecules, even though they share some of their features: for example, most are synthesized as linear polymers of a smaller molecule (the acetyl group on acetyl-CoA), and they self-assemble into larger structures (membranes).

Definition:

The lipids are a heterogeneous group of compounds related to fatty acids and include fats, oils, waxes and other related substances. These are oily or greasy organic substances, relatively insoluble in water and considerably soluble in organic solvents like ether, chloroform and benzene.

They are, thus, hydrophobic in nature. These are variously called as lipins or lipoids. The latter term is, however, sometimes used to refer “fat-like” substances which may not actually be related to the fatty acids. The term ‘lipid’ was first used by the German biochemist Bloor in 1943 for a major class of tissue components and foodstuffs.

lipids are molecular organic compounds, composed largely of carbon and hydrogen, that are essential for cell growth. Lipids are non-soluble in water and combine with carbohydrates and proteins to form the majority of all plant and animal cells. Lipids are more commonly synonymous with the word "fats" when speaking in terms of personal health, and though all fats are lipids, not all lipids are fats.

The three major purposes of lipids are energy storage, cell membrane development, and serving as a component of hormones and vitamins in the body. In healthcare, physicians order lipid tests or lipid profiles to measure cholesterol and triglycerides in a person's blood. Lipoprotein is the medical term used to define a combination of fat and protein.

Cholesterol is a naturally occurring substance in the body and is comprised of lipids. Cholesterol is separated into two types, high-density lipoprotein (HDL) and low-density lipoprotein (LDL). In a lipid test, the lipoproteins are separated so the level of each can be measured. Lipid tests are often part of preventative routine care, as they help determine whether there is significant risk for atherosclerosis, a hardening of the arteries that interferes with or interrupts blood flow. Lipoprotein levels are measured and dietary changes are usually in order when total cholesterol levels approach or rise above 200 milligrams per decilitre in the blood.

Fatty acids, also comprised of lipids, are an important dietary concern. Some fatty acids are essential and others are harmful. Fatty acids are categorized as mono-saturated, mono-unsaturated, and poly-unsaturated. Some essential fatty acids cannot be created by the body, and must be consumed in the diet. These include linoleic acid and alpha-linolenic acid.

 

Lipids & membranes 1

Lecture Series on BioChemistry I by Prof.S.Dasgupta, Dept of Chemistry, IIT Kharagpur.