22 Biology -- Biomolecules

Describe the functions of lipid .

1 Answers

Following are the functions of lipid:

1. Energy Storage: Lipids serve as a concentrated source of energy in the body. When broken down, they release more than twice the energy compared to carbohydrates or proteins. Adipose tissue, which is primarily composed of lipids, acts as a long-term energy reserve in the form of triglycerides.

2. Structural Component: Lipids play a crucial role in building and maintaining the structure of cell membranes. Phospholipids, a type of lipid, form a lipid bilayer that makes up the cell membrane, providing a barrier between the cell's internal environment and the external environment.

3. Insulation and Protection: Certain lipids, such as adipose tissue, help insulate and protect vital organs in the body. Adipose tissue acts as a cushion and thermal insulator, helping to maintain body temperature and protecting organs from mechanical damage.

4. Hormone Production: Lipids are involved in the production of various hormones in the body. Steroid hormones, including cortisol, estrogen, and testosterone, are derived from cholesterol, a type of lipid. These hormones play essential roles in regulating various physiological processes.

5. Absorption of Fat-Soluble Vitamins: Fat-soluble vitamins (A, D, E, and K) require lipids for their absorption in the digestive system. Lipids form micelles, which aid in the absorption of these vitamins from the intestines into the bloodstream.

6. Brain Function: The brain contains a significant amount of lipids, especially phospholipids. These lipids are crucial for the formation and maintenance of the myelin sheath, a protective layer surrounding nerve cells. Myelin facilitates efficient nerve signal transmission and is essential for proper brain function.

7. Source of Essential Fatty Acids: Some lipids, such as omega-3 and omega-6 fatty acids, are considered essential because the body cannot produce them. These fatty acids must be obtained from the diet and are vital for various physiological processes, including brain function, inflammation regulation, and cell membrane structure.

8. Transport Medium: Lipoproteins are complexes of lipids and proteins that transport lipids in the bloodstream. High-density lipoproteins (HDL) and low-density lipoproteins (LDL) are involved in transporting cholesterol and triglycerides to and from tissues, respectively.

9. Cell Signaling: Lipids act as signaling molecules in cell communication processes. Lipid-based signaling molecules, such as prostaglandins, leukotrienes, and thromboxanes, are involved in inflammation, blood clotting, and other physiological responses.

10. Thermal Regulation: Lipids, particularly subcutaneous fat, help regulate body temperature by providing insulation and preventing excessive heat loss. Fat acts as a thermal barrier, reducing heat transfer between the body's core and the external environment.

What does dextrorotatory and dextrorotation mean?

Dextrorotatory and dextrorotation are terms used in chemistry to describe the direction in which a substance rotates plane-polarized light. When a substance is said to be dextrorotatory, it means that it rotates plane-polarized light to the right or clockwise direction, whereas when it is levorotatory, it rotates plane-polarized light to the left or counterclockwise direction.

The terms "dextrorotatory" and "levorotatory" come from the Latin words "dexter" meaning "right" and "lævus" meaning...

What is the significance of RNA/DNA ratio in cell cycle ?

The RNA/DNA ratio is an important parameter that reflects the rate of protein synthesis in the cell and is therefore closely related to the cell cycle. The ratio of RNA to DNA in a cell can provide insights into the cell's metabolic state, growth rate, and overall health.

During the cell cycle, the RNA/DNA ratio is highest during the S-phase, which is the phase of the cell cycle when DNA is replicated. This increase in the RNA/DNA ratio during the S-phase is due to the fact that RNA synthesis...

1. Which of the following vitamins cannot be produced by our body?(a) vitamin A(b) vitamin K(c) vitamin C(d) All of the above Ans: (d) All of the above.

Vitamin C, also known as ascorbic acid, is a water-soluble vitamin that cannot be produced by the human body, which means it must be obtained from dietary sources. Vitamin C is essential for a wide range of biological functions, including collagen synthesis, wound healing, iron absorption, and immune system function.

Although most animals can synthesize their own vitamin C, humans and other primates lack the necessary enzyme L-gulonolactone oxidase, which is required for the synthesis of...

2.Which of the following vitamins are called fat-soluble vitamins?(a) vitamin B(b) vitamin E(c) vitamin C(d) vitamin B2Ans (b) vitamin E.

Easy trick you can follow is remember the name Kedar

R is not a vitamin and remaining four are fat soluble.

It will be easy to remember.

4.Which of the following is the most essential nutrient for a woman during her initial stages of pregnancy to prevent birth defects?(a) Thiamin(b) Folic acid(c) Vitamin C(d) Vitamin EAns:(b) Folic...

Folic acid is a B-vitamin that is essential for the proper development of the neural tube in a developing fetus. The neural tube is the embryonic structure that eventually forms the brain and spinal cord, and if it does not develop properly, it can result in birth defects such as spina bifida and anencephaly.

During the initial stages of pregnancy, it is especially important for women to consume adequate amounts of folic acid, ideally before conception and throughout the first trimester. The...

Define cellular pool

The collection of all the biomolecules present inside the cell is called cellular pool.

What are the identifying characteristics of structural polysaccharides?

The identifying characteristics of structural polysaccharides are as follows:

i) They have comparatively higher molecular weight than other carbohydrates

ii) They are non reducing sugar.

iii) They are insoluble in water and don't taste sweet.

Name two of the structural polysaccharides and storage polysaccharides

Structural polysaccharides: cellulose, peptidoglycanStorage polysaccharides: Starch, glycogen

Why amino acids are amphoteric in nature?

Amino acids are the organic acids having a basic amino (-NH₂) group attached to the chain containing acidic carboxyl

(-COOH) group . Since they have at least one basic amino group and one acidic carboxyl group, they are amphoteric in nature.

What do you mean by active site of an enzyme?

The binding site and the catalytic site of an enzyme are collectively called as active site of an enzyme.

Enzymes as a whole are not involved in catalytic activity, only a small part of it gets actively involved in substrate before going catalysis (binding site) and another small part involved in catalytic process (catalytic site)

Differentiate between micro molecules and macro molecules.

Micromolecules	Macromolecules
They are smaller molecules having lower molecular weight.	They are larger molecules with higher molecular weight.
They are formed by different elements like C,H,O,N etc.	They are formed by polymerization of large number of micromolecules
For eg: monosaccharide, amino acids, fatty acids, nucleotides etc.	For eg: polysaccharides, proteins, lipids, nucleic acids etc.

Differentiate between DNA and RNA

DNA	RNA
it is a double-stranded structure	it is a single-stranded structure
it is the hereditary material	it is nonhereditary material except for some viruses.
it replicates to form a new DNA molecule	it cannot replicate itself

Give two examples of polysaccharides

two examples of polysaccharides are starch and cellulose.

What are the biological roles of water?

Water is a vital substance for life on Earth, and it plays numerous important biological roles in living organisms. Some of the key biological roles of water are:

Universal solvent: Water is an excellent solvent for many substances, both organic and inorganic. This means that it can dissolve and transport a wide range of nutrients and minerals necessary for the growth and survival of living organisms.
Medium for metabolic reactions: Many metabolic reactions in living organisms require water...

What are the importance of DNA?

They are:

It is the principal genetic material that carries genetic information from generation to generation.
It controls all the biological activities of a cell. For example. protein synthesis.
It can replicate and form its own carbon copies.
It can synthesize RNA by the process of transcription.
The mutation is caused by changes in the sequence of nitrogen bases in DNA.

simple protein ma yeuta matra amino acid hunxa then peptide chain kasari hunxa ne??

Well you have mistaken it. Actually simple acids have only amino acid doesn't mean that they are composed of single amino acid only. It means they are composed by combination of many amino acids linked by peptide bond but consist no any external components like fats, starch and so on.

Hope you are clear now!

yo formation of lipid ma lipid kaha form vayo?? RCOOH ta xaina. How is lipid formed??

Well it's your misconception that every ester is lipid. Only the esters of fatty acids are lipids and in the above reaction ester is formed by the removal of a molecule of water. This is simply a general formula . In the same case if the akyl group(-R) is replaced by fatty acid (which is itself a hydrocarbon chain) then that's lipid. Hope you understood.

is ester lipid?

Yes, ester may be lipid but note that only the ester of fatty acids are lipids. Esters (CH-O) are the bond formed between alcohol group and carboxylic acid (-COOH) by the removal of a molecule of water. And if such bond is formed between fatty acid that's lipid. Similarly ester bond can also be formed between Penrose sugar and phosphate group in DNA to form phosphodiester bond which is actually not a lipid so be careful that only the ester bond between fatty acids can be considered as lipids....

Define Storage polysaccharides with example.

Storage polysaccharides are a polysaccharide that occurs in a living organism as a form of stored energy.

Storage polysaccharides include the glycogen in animals and the starch and fructosan in plants.

Examples of polysaccharides : Starch, cellulose and glycogen.

Polysaccharides are also formed as products of bacterial, for example, in yogurt production.

Mention differences between fats and oils.

Why do fat release more energy than carbohydrates on oxidation?

Because the fats have a higher percentage of C and H and lower percentage of O in their molecular structure than the carbohydrates.

Difference between Saturated fatty acids and unsaturated fatty acids.

Explain how Glycosidic bonds are formed?

When hydroxyl group of one monomer comes to lie adjacent to the hydrogen of another amino acid then through dehydration reaction ie by the loss of one water molecule, a covalent bond is formed which is termed aglyosidicbond.

Describe function of polysaccharides in living organism.

Polysaccharides, or polycarbohydrates , are the most abundant carbohydrate found in food which provides very important dietary elements for human nutrition. It can be starch , cellulose or glycogen. They are important class of biological polymers. It's function in living organism is generallly either energy storage or structual support.

Describe structure of DNA according to Watson and Crick Model.

Watson and Crick described DNA as a double helix that contained two long, helical strands wound together. In their model, each DNA strand contained individual units called bases, and the bases along one DNA strand matched the bases along the other DNA strand. Some characteristics of this DNA are,

a.) DNA consists of about 10^10 deoxyribonucleotides.

b.) The diameter of DNA is about 20 Angstrom.

c.) Nitrogen bases are of two types: purines (Adenine and Guanine) and pyrimidines (Cytosine and...

Explain function of amino acids.

Amino acids are molecules that combine to form protein. Some of the important function of amino acids are;

a.) Amino acid are building block of proteins .

b.) Amino acids are amphoteric(able to react both as an acid and a base), thus they can buffer in solutions, resisting change in pH .

c.) Histidine are found in active site of enzymes where it causes making and breaking of bonds.

d.) Cysteine links chain together by forming disulfide bonds.

e.) The non- protein amino acids are useful compounds...

How does water help in maintaining the constancy of the internal environment of an organism?

Maintaining the constancy of internal environment of an organism ishomeostasis. Water plays an important role in maintaining homeostasis which are mentioned below;

Water dissolves gases thus, helps in exchange and transportation of oxygen and carbondioxide.
Water , when excreted removes water soluble toxins from the body.
Water helps to remove excess heat from body in form of sweat that helps to regulate body temperature.

Difference between aldose sugar and ketose sugar.

Describe the Structure and function of ATP.

ATP (Adenosine Tri Phosphate ) is a nucleotide that consists of three main structure which includes the nitrogenous base, adenine; the sugar , ribose ; and a chain of three phosphate groups bound to ribose.

It is the major molecule for storing and transferring energy in cells . It is often referred to as the energy currency of the cell .

For more information, watch this informative video.

https://www.youtube.com/watch?v=hA4sRESz6Uw

How are amino acids bonded together? Describe how these bonds are formed?

When the carboxyl group of one amino acid comes to lie adjacent to the amino group of another amino acid then with the loss of one H20 molecule (i.e through dehydration) a covalent bond is formed in between them which is called a peptide bond.

Difference between fats and oils .

Describe the structure of protein and it's functions.

Proteins are complex molecules that play essential roles in living organisms. They are made up of long chains of amino acids, which are organic compounds. The structure of a protein consists of four levels: primary, secondary, tertiary, and quaternary.

1. Primary structure: This refers to the specific sequence of amino acids in a protein chain. The order of amino acids is determined by the genetic code encoded in the DNA of an organism.

2. Secondary structure: Protein chains often fold into...

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