Introduction to Nucleic Acid Biochemistry

Summary

Highlights

• Introduction to nucleic acids as genetic carriers. 🧬
• Discussing DNA's structure and role in cells. 🏗️
• Explaining nucleotide components and bonding. 🔗
• Differentiating DNA and RNA. 🔄
• Detailing the function of nucleotides in energy metabolism. ⚡
• Emphasizing the complementary nature of DNA strands. 🔄

Key Takeaways

• DNA and RNA are the primary carriers of genetic information. 📚
• DNA is a double-stranded helix, while RNA is single-stranded. 🧬
• Nucleotides consist of a sugar, a phosphate group, and a nitrogenous base. 🍬
• Adenine pairs with thymine in DNA, but with uracil in RNA. 🔄
• Energy metabolism involves nucleotides like ATP. ⚡
• DNA strands are complementary and run anti-parallel. 🔄

Overview

Chapters

• 00:00 - 00:30: Introduction to Nucleic Acids Nucleic acids are biochemical molecules that are essential for life. They include DNA and RNA, which play crucial roles in genetic information storage and transfer. DNA is responsible for storing and transmitting genetic information, while RNA is involved in protein synthesis and various regulatory processes. The structure of nucleic acids is composed of chains of nucleotides, which are the building blocks consisting of a sugar, a phosphate group, and a nitrogenous base. Understanding nucleic acids is fundamental in biochemistry due to their role in heredity, evolution, and cellular functions. The study of nucleic acids encompasses their chemical properties, biological functions, and applications in fields like medicine and biotechnology.
• 00:30 - 01:00: Types of Genetic Carriers In the chapter titled 'Types of Genetic Carriers,' the discussion focuses on molecules that carry genetic information, specifically DNA and RNA. These molecules, referred to as the two types of genetic carrier molecules, are essential for the transmission and storage of genetic information as nucleic acids. The chapter will explore these two types, highlighting their roles and characteristics in the broader context of genetics.
• 01:00 - 01:30: Introduction to DNA DNA is a molecule present in almost every living cell, serving as the primary material containing biological instructions. It is crucial for defining the characteristics of each human and other living organisms.
• 01:30 - 02:30: DNA Structure and Function The chapter titled 'DNA Structure and Function' focuses on the unique aspects of DNA in organisms. It highlights DNA's role in protein synthesis and reproduction. The chapter describes DNA's iconic twisted helical structure, emphasizing its double-stranded nature.
• 02:30 - 04:00: Nucleotide Structure The chapter 'Nucleotide Structure' discusses the pairing of nucleotides in a DNA strand. Adenine pairs with Thymine via two hydrogen bonds, and Guanine pairs with Cytosine. These pairings are part of the fundamental structure of DNA.
• 04:00 - 05:30: Functions of Nucleotides and Nucleic Acids This chapter delves into the functions of nucleotides and nucleic acids. It begins by explaining that DNA, which stands for deoxyribonucleic acid, is a chemical substance. The chapter highlights the common hydrogen bonds between cytosine and another component, emphasizing the importance of these interactions in the structure and function of DNA. Overall, the focus is on the crucial roles that nucleotides and nucleic acids play in biological processes.
• 05:30 - 07:30: Hydrogen Bonding in DNA This chapter focuses on hydrogen bonding in DNA, providing an overview of its role in cellular structure and function. It starts by discussing the presence of DNA in the nucleus of all living cells and its influence on the chemical changes within these cells. The chapter emphasizes the specialized roles that different cells undertake in the body, which are all influenced by the genetic information encoded within DNA and the crucial hydrogen bonds that maintain its structure.
• 07:30 - 09:00: Primary Structure of Nucleic Acids The chapter 'Primary Structure of Nucleic Acids' primarily discusses various types of cells found in different tissues. It introduces myocytes, which are muscle cells, and ocytes, which are within the blood, including white and red blood cells. The chapter also mentions nerve cells, providing a basic overview of cell types involved in these biological structures.
• 09:00 - 10:30: Properties of DNA The chapter 'Properties of DNA' discusses how DNA controls the cells that are formed. It explains that DNA is a large molecule composed of long chains of subunits. The chapter emphasizes the size and complexity of the DNA molecule.
• 10:30 - 11:00: Conclusion and Next Steps The final chapter titled 'Conclusion and Next Steps' delves into the fundamental components of nucleotides. It outlines how nucleotides, which are the building blocks of DNA, are composed of subunits. Each nucleotide consists of a sugar component known as deoxyribose, characterized by its five-carbon structure. This explanation serves as a wrap-up of the molecular composition discussed throughout the material, while also setting the stage for further exploration of biological macromolecules in subsequent studies.

Introduction to Nucleic Acid Biochemistry Transcription

• 00:00 - 00:30 good day students you are welcome to another lecture episode on introduction to nucleic acid biochemistry so when we talk about nucleic acids we are going to be discussing about the molecules that are
• 00:30 - 01:00 genetic carriers or the carriers of genetic information and we have two types of uh genetic carrier molecules molecules that carries genetic information uh we are talking about DNA and RNA so these are the two types of nucleic acid that we are going to be uh
• 01:00 - 01:30 discussing so first and foremost we talk about DNA and DNA is a molecule that is found in almost every living cell it serves as aary material containing biological instructions it contains biological instructions that make each human and
• 01:30 - 02:00 other organism unique so it DNA it helps the cell to make proteins and it also helps in facilitating reproduction it has from the structure you can see it has a twisted helical structure and it is double stranded it means two
• 02:00 - 02:30 strand uh are joined together and it has uh some nucleotides that pairs with each other it has adenine that appears With Thine and guanine that appears with uh cyto adenine andine bond it is connected via two hydrogen bonds and guanine pairs
• 02:30 - 03:00 with cyto via three hydrogen bonds so we are going to discuss that in detail so DNA stands for deoxy ribonucleic acid deoxy ribonucleic acidd and the it is a chemical substance
• 03:00 - 03:30 that is present in the nucleus of all cells in living organisms and it controls chemical changes that take place in the cell so cells in the body you know different cells specialize to form
• 03:30 - 04:00 different tissues and for each of those cells we talk about myocytes these are cells that are found in the moosul so cells that form mosles and ocytes that are found in the blood we have blood has we have the white blood cells and the red blood cells and we have the the nerve cells also and all these
• 04:00 - 04:30 cells that are formed they are controlled by the DNA so when we look at the DNA molecule in its entirety it is a very large molecule that is made up of long chain of subunits so DNA molecule uh is very long uh long molecule that is uh made up of what 10 of sub
• 04:30 - 05:00 units and this sub units are what we call the the nucleotide so the subunits are called nucleotide and each nucleotide is made up of a sugar that is called the oyos it is a f carbon
• 05:00 - 05:30 sugar that is called deoxy ribos so it means it does not contain o h at position two of sugar and it has also a phosphate group and an organic an organic base nitrogenous base so nuclear
• 05:30 - 06:00 acids and nucleotides when we talk about nucleic acids we are generally referring to the DNA and the RNA DNA de oxy ribonucleic acid and RNA it's ribonucleic acid they are the carriers of what genetic information and the nucleic acids they are biological polymers that are made up
• 06:00 - 06:30 of nucleotides and and they also call they also have pentos sugars Al pentoses that are linked to the purine or pamine base and also a phosphate group so when we say purine molecules
• 06:30 - 07:00 we are talking about those nucleotides that made up the uh the that's made up the the cells that is the building block of the DNA and also we have the the the PID so for the
• 07:00 - 07:30 purines the purines are examples of P purins are adenine rather examples of purines include adenine and guanine so Adine and guanine are purines while Pines include the cyto thamin and uracil CT U okay CTU for
• 07:30 - 08:00 pins and AG adenine and Guin serve as uh as purines so for adenine it is abbreviated as aan abated as G and cyto abated as C tun uril U so that is why the genetic code you is represented as actg and so on and
• 08:00 - 08:30 so forth so for DNA you have your actg ording in combination depending on a pi with t and GP with C while in RNA you have you don't have t in RNA rather you have what we call urasil okay so urasil replace timing in RNA so in RNA you are going to have
• 08:30 - 09:00 so the the sugars that are found can be
• 09:00 - 09:30 either the ribos or the oxy ribos as in the case of DNA or as a case of RNA or DNA respectively so in DNA we have the oxos while in R we have the ribos so if we look at the structure we have sugar and nitrogenous base to form what we call a uh a nucleoside so a nucleoside is is
• 09:30 - 10:00 having sugar and a nitrogenous base and when a phosphate group is attached to the sugar we have what we call a nucleotide and many of these nucleotides come together this is the monomeric unit the nucleotide to form the polymeric nuclic acid so the heterocycles that are found
• 10:00 - 10:30 in DNA and RNA we have the adenine Quine cytosin and thamin that are found in DNA and DNA while in RNA we have uril in place of timing and structurally and this is how they look like we have the adenine that is represented as a can be found in both DNA and RNA and we have the
• 10:30 - 11:00 Quan that is can be found in both DNA and RNA and we have the cyto that is found in DNA and RNA then thine that is only found in DNA and urasil only found in RNA remember in terms of whether it is purine or purine uh nitrogenous base uh we we
• 11:00 - 11:30 said that uh adenine and guanine are purines while cyto thine and uracil are pins so the O ribonucleotides that are found in DNA uh for the nucleotid and there are
• 11:30 - 12:00 symbols and also the nucleotides so nucleotides are the combination of the nitrogenous base the sugar and the phosphate group while the nucleoside is the nitrogenous base the sugar without the phosphate group and they have their own representation So structurally when you say de oxy adalite it is De oxy adinos five Prime monophosphate and it
• 12:00 - 12:30 can be represented as as a o a or the M okay so um for the nucleoside form it is called deoxy adenosine and it is represented as da for the next one it can be represented as g d g or D GM P
• 12:30 - 13:00 that is the oxy guate or the oxy guanosine 5 Prime on phosphate and the nuc side is the oxy guanosine and represented as as the G so also for the thine you have DT for the de oxyamine as the nucleo side so also DC for the oedin for cyto nucleosides and you have the
• 13:00 - 13:30 different nucleotides here represented so for the de oxy ribonucleotide that is those that are found within the an we have the two prime deoxyadenosine five Prime monop phosphate and we have the two prime oxy onein five Prime Prime monophosphate as
• 13:30 - 14:00 in the case of either iDine that is here or guanine and if cyto we have 2 Prime de oxin five Prime phosphate and we have the foramin is 2 Prime oxyamine 5 Prime phosphate so this they are found in the DNA okay they are the oxyon nucleotid they are found in DNA when while here
• 14:00 - 14:30 the the the the oxy ribonucleotides that are found in the DNA also so it's still uh the same uh representation here so the hydrogen bonding interaction so two bases can form hydrogen bond between them for monom large number of base pairs is uh is
• 14:30 - 15:00 possible for in in while in Pol nucleotide only few possibilities exist so if you look at whatson Creek based PA pred dominate in double stranded DNA where adenine pairs with thine two hydrogen bonds cytosine pairs with Quine with two hydrogen bonds so these are purine pairs that pairs with the uh p
• 15:00 - 15:30 okay so the building block molecule of nucleic acids are the nucleotides in RNA we have the CMP GMP and TMP while in D in DNA we have the D the the CMP uh the the GMP and the U
• 15:30 - 16:00 so functions of nucleotid and nucleic acids so um nucleotid functions they function in uh for energy metabolism where ATP is the uh energy currency that's the
• 16:00 - 16:30 universal energy currency and all living organisms utilizes energy in form of ATP and they also they are found in in enzyme co-actors such as adenine nicotinamide adenine D nucleotide serve as a co-actor for some enzymes and also in Signal trans transaction such as
• 16:30 - 17:00 cyclic so for nucleic acid uh function the functions in form of storage of genetic information in DNA transmission of genetic information in Binger RNA in processing of genetic information ribosomes and protein synthesis where you have drna Transfer RNA and ribosomal AR so the linkage between the molecules
• 17:00 - 17:30 is in form of phosphor di linkage or phosphor di Bri you have the three Prime Terminal and also five Prime teral in the nucleotide residual so nucleotide composition is of three parts we have the de oyibos sugar without the oxygen in the to carbon and we have phosphate group we have one of the four types of
• 17:30 - 18:00 bases that are all nitrogen containing we have the adamine adenine thine that is only found in DNA and cytosine that is uh found in uh both DNA and RN and Guan also so best paing in is based on the Wason Creek model in 1953 if you remember from our previous uh lecture video on the history of science that
• 18:00 - 18:30 made scientist that made contribution scientist that made contribution breakthrough in Biochemistry you remember in 1853 Wason and Creek they noted that DNA consists of two Pol nucleotide strand running in opposite direction and they coil around each other in a double helix and the strands are held together by hydrogen bonds between specific base pairs and adenine and thamin form strong hydrogen
• 18:30 - 19:00 bonds with each other okay in two hydrogen bonds with each other but not they don't form hydrogen means a do not pair with G or C and T do not pair with t with C or G rather C pairs with G so G and cyto and guanine form strong hydrogen bonds between each other but they do not form uh hydrogen bonds between uh G and a or G T or C and A O C
• 19:00 - 19:30 and T so the GC hydrogen bond is three while the aogen bond is two and the difference in the Strand are that the strand of DNA are complementary because of hydrogen bond and wherever G occurs in one strand is C occurs in the opposite in the other opposite strand okay because you remember remember the double helical nature of the DNA okay so
• 19:30 - 20:00 in the double stranded one strand of the DNA if a is there in one strand opposite to it that they form the hydrogen bond you must see a t that is going towards the opposite direction so when an a occurs in one Str a t occurs in the other Str as simple as that so if you look at the base pairing and
• 20:00 - 20:30 the arrangement the phosphor diester linkage is in three frame five Prime Direction so we look at the phosphate Bridge here phos forer Bridge here okay that link one nucleotide one nucleotide to another to form a continuous uh polymeric unit DNA so the primary structure of nucleic acid it uh is that you have a
• 20:30 - 21:00 nucleotide phosphate group sugar and nitrogenous base that forms a with that reacts with another link with another nucleotide with the formation of an ester bond to form phospho diester Bond so you have it the five Prime oh sorry the three prime o of one nucleotide
• 21:00 - 21:30 form uh a a bond with the oxygen or the phosphate group of another molecule of the nucleotide in the five Prime uh uh position so you have what the five Prime free five Prime phosphate that is ready to be attached to another nucleotide that is having the O3 Prime and you have
• 21:30 - 22:00 what threee o here fre Hydrox group that is ready to attach to another five Prime three five Prime phosphate of another nucleotide so that is how the molecule build up the polymer Builds on so the primary structure of nucleic acid is the what nucleotide sequence and the nucleotid in nucleic acid are join by phospho diester Bond
• 22:00 - 22:30 and O 3 Prime o of the sugar in one nucleotide forms an esta bond to the phosphate group on the F Prime carbon of the other sugar that is next in the nucleotide so generalized structure of DNA looks like you have five Prime three five Prime phosphate group the end and
• 22:30 - 23:00 you have phosphate group the sugar attached to the base the phate group attached in the next nucleotide and you have the phosphate group sugar base and the three prime and fre okay this is how it looks like uh similar to what we uh demonstrated so the rum primary structure looks like like this where you
• 23:00 - 23:30 have a and you have C here you have G have t in what you have the in five Prime three prime direction or three prime five Prime Direction and for the next strand it will be the three prime five Prime Direction so a nucleus a nuclic acid polymer has a free P Prime phosphate group at one end and a free three Prime oh group at the other end
• 23:30 - 24:00 the sequence is read from the three five prime using the letters of the bases from the three five Prime you have a c d t that's how you read it from five Prime to three prime and this example read as what P prime a c g T3 Prime that is how the sequence read example of DNA Prime structure the the ox nucle acid here 3
• 24:00 - 24:30 Prime okay and you have the the adenine here adenine is here while here is cyto you have your three prime phosphor diester Bond and you have another three prime prime phosphor diester Bond so this is how it's uh looks like five prime a c d c
• 24:30 - 25:00 three frame so in the DNA we have AC GT are links by three prime five Prime phosphor diester bonds between the the oxos and the phosphate group so nuclic acid structure the polymerization looks like this okay you have your a g a and guine here adenine here thine and cyto
• 25:00 - 25:30 here and you have three prime three five Prime phosphate end here and the three prime or hydroxy group three here so you have a sugar phosphate backbone and you have the nucleotides and it looks like this in DNA and and also in the RNA so you remember in DNA you have what the the oxos and while in R you have the
• 25:30 - 26:00 the Ros so the sequences can be described as to be said is a chain that is from five Prime and identifying the bases in order of their occurrence using the abbreviations a for adenosine G for guanosine c for citadine and T for iDine or U for uril in R and typical sequence
• 26:00 - 26:30 is written as t a g d c so properties of DNA is a double helic it's a double hel double helical nature and the strand of the DNA is anti parallel it means one strand is is opposite to the other strand if one strand is going from P Prime to 30 prime the other strand will go uh in three prime P Prime Direction with G pairs
• 26:30 - 27:00 with C can see G pair with C with three hydrogen bonds and a pairs with t with two hydrogen bonds and the Strand are complementary there are hydrogen bond forces okay so the Str are complementary in that the number of G are equals to the number of c and number of a are equals to the number of T there are base stacking interactions and there are 10
• 27:00 - 27:30 base pairs per per ton before each tone because it's it's twisted helical before each tone there are 10 B so this is another representation of how the structure look likees okay so for the five Prime three prime Direction looks like this while the
• 27:30 - 28:00 three prime uh the five Prime three Prime in the opposite direction it looks inverted so um thank you we are going to stop here uh when we come next we will discuss uh uh more on the uh possible combination uh and also the uh more explanation so if you have any question you can drop it at the comment section and you are uh going to be covered and
• 28:00 - 28:30 it's going to be addressed thank you see you in the next video