Nucleic bases, nucleosides and nucleotides gathering in the structure of nucleic acids, namely DNA and RNA. Nucleic acids properties. Replication and translation. Reparative enzymes deficiency diseases.
Types and functions of RNA. Of the many types of RNA, the three most well-known and most commonly studied are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA),
This slide presentaion contains information about Ribonucleic Acid. Its structure, types, components, bases and functions. Also, included in this presentation is the process of Protein Synthesis.
UNIT IV Nucleic acid metabolism and genetic information.pptxAshwiniBhoir2
Biosynthesis of purine and pyrimidine nucleotides
Catabolism of purine nucleotides, Hyperuricemia and Gout disease
Organization of mammalian genome
Structure of DNA and RNA and their functions
DNA replication (semi-conservative model)
Transcription or RNA synthesis
Types and functions of RNA. Of the many types of RNA, the three most well-known and most commonly studied are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA),
This slide presentaion contains information about Ribonucleic Acid. Its structure, types, components, bases and functions. Also, included in this presentation is the process of Protein Synthesis.
UNIT IV Nucleic acid metabolism and genetic information.pptxAshwiniBhoir2
Biosynthesis of purine and pyrimidine nucleotides
Catabolism of purine nucleotides, Hyperuricemia and Gout disease
Organization of mammalian genome
Structure of DNA and RNA and their functions
DNA replication (semi-conservative model)
Transcription or RNA synthesis
Biochemistry of nucleic acids DNA RNA structures with the comparison chart between them chemistry of nucleic acids structures and composition and protein synthesis nucleotides and nucleosides
Enzymes mechanism of action, their specificity types, active center structure and action, inhibitor types, fisher and Koshlend theory are presented. Enzymes classification, a new class of enzymes discovered recently, detailed explanation of each class reaction types is presented as well
Main simple and complex proteins along with their classification are presented. Simple proteins main features. Gluten disease. Nucleic acids. Chromatine. Participation in transcription and replication. Detailed explanation of DNA and RNA structure
1 Main minerals. Amino acids. Proteins folding 2021Mahiraamirova1
Presentation gives detailed description of proteins formation and explains some minerals role and their sources. Physico-chemical properties of amino acids and their role in bond formation are overviewed as well
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
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Nucleic acids 2020
1. Biochemical properties of nucleic
acids. Matrix biosynthesis process
Year 2021
Mahira Amirova
Associate Professor
Biochemistry Department
Azerbaijan Medical University
Year 2021
In The Name of Allah, The Most Merciful, The Most
Compassionate
6. Xanthine and hypoxanthine are also purines,
but they are not costituents of nucleic acids.
Uric acid is also a purine, but this waste
product is washed out with urine.
Orotic acid is a pyrimidine, that does not
present in NA, but is used as an anabolic drug.
In normal urine, there are xanthine and uric
acid, but there is no guanine!
After incomplete hydrolysis of NA, nucleosides are formed:
(deoxy) adenosine,
(deoxy) guanosine,
(deoxy) cytidine,
(deoxy) thymidine,
Uridine
Purine nucleosides
Pyrimidine nucleosides
Purines and
pyrimidines not
present in nucleic
acids
7. Instead of Uracil present in RNA , in
DNA occurs Thymine.
(in RNA)
(in DNA)
CH3
In DNA is absent uracil, in RNA there is no thymine.
9. Adenine and Guanine bind ribose at 9th nitrogen
atom, while Cytosine and Thymine – at 1st
nitrogen.
Point of ribose connection
9 9 1 1
10. RIBOSE and DEOXYRIBOSE
In order not to mix atoms of nitrogenous base with
atoms of carbohydrate ring, the latter are indicated by the sign ` (prime)
Piont of nitrogenous base connection
12. Nucleotide dAMP = nucleoside
(adenosine)+phosphate
NUCLEOSIDE
ADENOSINE
With incomplete hydrolysis of nucleic acid,
nucleoside and phosphoric acid are formed.
13. With complete hydrolysis of nucleic acid (NA),
nitrogen base, monosaccharide pentose and
phosphoric acid are formed.
14. TYPES OF NUCLEOTIDES
(d)AMP, (d)ADP, (d) ATP - (deoxy)-adenylic acid
(d)GMP, (d)GDP, (d)GTP - (deoxy)-guanylic acid
(d)CMP, (d)CDP, (d) CTP - (deoxy)-cytidylic acid
(d)TMP, (d)TDP, (d) TTP - (deoxy)-thymidylic
acid
UMP, UDP, UTP - uridilyc acid
Cyclic nucleotides as cAMP, cGTP are the secondary
messengers in hormonal signal transmission
to the cell.
15. The primary structure of the NA is the sequence of
mononucleotides in the polynucleotide chain.
In the synthesis of NA, nucleoside-5'-
triphosphates are used as the main material.
Therefore, the 5'-end of NA always remains in the
form of 5'-triphosphate. But at the 3’-end always
present a free OH-group.
The polynucleotide has 3 structural levels: primary,
secondary and tertiary.
The primary structure of DNA is determined by
spliting DNA with restrictase enzymes into small
fragments. Each restrictase is specific for a certain
nucleotide sequence.
16. The secondary structure of RNA is formed due to the
binding of nitrogenous bases in some sites according to the
principle of complementarity.
Types of RNA are: r-RNA, t-RNA, m-RNA.
ап
To the tertiary
structure
18. tRNA secondary structure (clover leaf)
Acceptor
arm
Region of hydrogen binding
between nitrogenous bases
Anticodon arm
Alkylated purine
Amino
acid
Extra arm
25. 2 hydrogen bond are formed between A and T, 3
hydrogen bonds between G and C
Complementarity means:
binding of A with T only and
G –with C only.
26. The secondary structure of the NA is the spatial configuration of
the NA. For DNA, the Chargaff’s law are valid:
• 1. Sum of purines is equal to pyrimidines:
A + G = C + T.
• 2. The number of A will equal T,
and G = C.
• 3. А + C always equals G + Т
(for RNA this А + C= G + U rule is valid only).
• 4. G+C/ A+T. This is the DNA specificity ratio . In
human, the DNA is of the adenine-thymine type,
since its ratio equals 0.6.
28. Histones and protamines are connected with DNA.
These proteins are simple proteins of alkaline nature
present in cell nucleus. According to the modern
classification, they are not proteins, but peptides.
Examples of protamines from fish are:
•salmine from salmon
•Scumbrin from mackerel
•clupeine from herring
•iridine from rainbow trout
•thinnine from tunafish
•stelline from starry sturgeon
•scylliorhinine from dogfish
30. HISTONES CONTAIN BASIC AMINO
ACIDS
• Histones contain a lot of arginine and lysine,
so their pİ = 9-12.
In histones, tryptophan does not occur.
• In the nucleosome, the DNA helix is wrapped
1.75 times around 8 histone molecules.
31. HISTONES PROVIDE CONDENSATION OF chromosome and DNA turning. In chromatin
present DNA, histones, non-histone proteins (regulate chromatin’s activity), some RNA.
In the nucleus of each cell, the DNA molecule is packaged into thread-
like structures called chromosomes. Ergo, eukaryotic DNA is found in the chromosome of
the nucleus. DNA is also found in mitochondria.
32. TYPES OF HISTONES
The DNA region between the nucleosomes
is associated with H1 histone.
34. • REPRODUCTION by DNA (RNA) its own
ANALOGUE IS REPLICATION.
IT PROCEEDS ON THE BASIS OF
COMPLEMENTARITY.
GENETIC INFORMATION IS TRANSMITTED BY THE
MECHANISM OF THE MATRIX.
• THE TEMPLATE for replication and transcription
can be DNA OR RNA.
According to Watson and Crick model, REPLICATION
FOLLOWS SEMI-CONSERVATIVE PATH
35. DNA-TOPOISOMERASE CHANGES THE NUMBER
OF TURNS IN DNA HELIX. IT WEAKENS OR
STRENGTHENS DNA STRUCTURE (At initiation of
replication DNA topoisomerase breaks 3'5’-
phosphodiester bonds in DNA. When replication ends,
the same enzyme stitches the break point).
HELİCASE, at the expense of ATP uncoils double
HELIX of DNA.
DNA polymerase synthesizes DNA.
ONE POLYMERASE IS PRIMASE, SYNTHESIZING
OLIGORIBONUCLEOTIDE. First the primer, oligo-RN is
synthesized.
36. HELICASE, TOPO-ISOMERASE (breaks and stitches
3’5’phosphodiester bonds), LIGASE, PRIMASE,
POLYMERASE
HELICASE uncoils
double helix
TOPOISOMERASE
changes the number of turns
37. Therefore the
5’END (as in all
triphosphates) is
aways in the form
of TRIPHOSPHATE
While 3’END has a free OH-
GROUP
In the synthesis
oF NA as the
primary matherial
are used NTPs
(nucleoside
triphosphates)
DNA replication proceeds in 3 steps:
1) Initiation;
2) Elongation;
3) Termination
3`-End
5`-End
38. The lead chain is synthesized in the direction of DNA
unwinding, i.e. 5’ ⟹ 3 ’. Therefore, the lead chain is
synthesized faster.
The lagging chain is synthesized more slowly, because it is synthesized in the direction opposite
to unwinding, in the form of Okazaki fragments. About 200 mononucleotides present in each
Okazaki fragment.
For each Okazaki fragment a
primer, a short oligo-
ribonucleotide, is also
synthesized. This synthesis also
occurs in the direction 5’3 ’
40. TRANSCRIPTION is the SYNTHESIS OF
RNA ON DNA.
The transcriptional template can be DNA and RNA.
RNA SYNTHESIS IS PRODUCED BY RNA-POLYMERASE,
or TRANCRIPTASE.
First are formed immature pre-rRNA, pre-mRNA and
pre-tRNA.
RNA-POLYMERASE I SYNTHESIZES rRNA
RNA-POLYMERASE II SYNTHESIZES mRNA
RNA-POLYMERASE III SYNTHESIZES tRNA
When DNA IS SYNTHESIZED ON RNA, IT IS A REVERSE
TRANSCRIPTION
41. Transcribed DNA is located in the fragment between
the nucleosomes, or on the linear nucleosome.
Globular
nucleosome of DNA
is always inactive.
Linear nucleosome
42. The TRANSCRIBED REGION OF DNA (between promoter
and terminator) is called TRANSCRIPTON (operon)
3` cystrons (informative section of transcripton) 5`
cistron
Informative part of cistron is called EXON.
terminato
pre-
ewly synthetized polypeptide,
on-active
(processing)
(active)
44. There is a PROMOTER on the top of transcripton.
PROMOTER site is called an operator in prokaryotes.
This site binds RNA-polymerase
•
Cistrone is a structural DNA gene, which stores information about
RNA that is responsible for amino acid sequence in protein.
There is a terminator site at the end of operon . It stores an
information about the end of transcription.
Promoter site,
binds RNA-
polymerase
Terminator site
45. ADDITIONAL REGULATORY SITES of
operon
Acceptor (regulatory) zone follows promotor
site. It is sensitive to regulatory factors. It
binds the repressors and can stop
transcription if needed.
Enhancer zone is an inductor zone, which
enhances transcription rate if needed.
47. RNA-polymerase. There are α-, β-, δ-
RNA-polymerases.
• As all polymerases, RNA-polymerase moves in
direction 5’3’, i.e. in direction of unwinding.
• As always, 3’-end comprises free OH-, while
5’-end ends with triphosphate.
The synthesis of all RNA starts with purines
(Adenine or Guanine)
48. POST-TRANSCRIPTIONAL PROCESSING
OF RNA
4 CHANGES in pre-RNA:
1) -CLEAVAGE OF non-informative introns
2) -SPLICING OF exons by ligases
3) -POLYADENYLATION of 3’end
4) -KEPING of 5’end, that increases the resistance of
RNA to nucleases. In kep, 5’5’ phosphodiester bond
is formed with the methyl-GTP
49. For a protein-coding gene, the RNA
copy, or transcript, carries the
information needed to build a
polypeptide (protein).
poly-Adenyl site
C
A
P
EXONS
50. In the end, we obtain a
MATURE mRNA
-OH
MATURE RNA is transferred from nucleus to cytoplasm with protein INFORMER.
51. Reverse transcriptase of oncoviruses,
tumor cells
1. Reverse transcriptase (RNA –DEPENDENT DNA-
polymerase) SYNTHESIZES DNA on RNA
template.
2. There is also RNA-REPLICASE, THAT SYNTHESIZES
RNA on RNA.
• Mutation mean any change in the DNA. We can
refine that definition: a mutation is a change in
the DNA base sequence, that results in a change
of amino acids in the polypeptide coded for by
that gene.
52. Spontaneous DNA damages are:
1) replication errors
2) depurination
3) deamination, when adenine becoms hypoxanthine, guanine -
xanthine, cytosine - uracil.
Physical and chemical factors result in following damage effect:
1. Alkylation of nitrogenous bases. During this process, the
formation of methyl guanine, methyl adenine occur.
2. Dimerization of pyrimidines under the UV radiation. Two
neighboring pyrimidine form a dimer called thymine dimers.
53. Reparative enzymes change the “mistaken” nucleotides to
the “healthy” ones.Their insufficiency leads to severe diseases,
for example xeroderma pigmentosum. Violation of reparative
system breaks renovation of damaged DNA. Reparative, anti-
mutagenic enzyme system includes:
• DNA exonuclease, which cleaves the damaged area.
• Uracil-DNA-glucosidase, which cleaves uracile from
deoxyribose.
• β- DNA polymerase and DNA ligase.
Reparative enzymes
54. XERODERMA PIGMENTOSUM- disease based on
insufficiency of DNA reparative enzymes
These patients do not
have DNA-nucleases to
break off the error
nitrogenous bases.
Severe sunburn after only a
few minutes in the
sun, freckling in sun exposed
areas, dry skin, changes in
skin pigmentation are only
few symptomes of this
disease.
Its severe form is called
De Sanctis-Kakkone.
55. RNA types
rRNA makes up more than 80% of cell RNAs (more
than any other RNA), has the largest molecular weight and
accumulates in the ribosome. It works as a framework of
ribosome.
mRNA is a template for reading the sequence of
amino acids in the peptide chain
57. : mRNA
D
N
A
m-RNA constitutes minimum amount of cell RNAs, 5% only.
mRNA is synthesized on DNA cistron according to the principle of
complementarity. The mRNA consists of the codon triplets. Each
triplet encodes certain amino acid.
The genetic code consists of 61 «amino-acid coding codons» and
three termination codons, which stop the process of translation.
58. tRNA features
tRNA is abundant in minor nucleotides. Minor pyrimidines are:
methyl-cytosine, hydroxymethyl-cytosine, methyl uracil,
thio-uracil,
dihydro-uracil.
Minor nucleoside is:
pseudouridine
tRNA is called soluble RNA. It transports amino
acids to the ribosome. Each t-RNA can bind only
one amino acid. Ergo, there are at least 20 tRNAs.
59. MINOR pyrimidine of tRNA, methyl-cytosine
cytosine Additional methyl group
in methyl-cytosine
60. SECONDARY structure of tRNA resembles to a
“clover leaf”.
CCA-
end
on the complementarity
principle
Reading direction
The amino
acid is
attached to
3’end
adenine -OH
group.
Consequently
, the CCA
triplet on
tRNA 3’end
is called the
“acceptor
zone”.
At the 5’-end occurs G.
3’-terminus ends with a
C-C-A triplet. Ergo, 3’-terminus of
tRNA always ends with A
61. TERTIARY structure of tRNA
The tertiary structure of
tRNA resembles to an elbow
bend. This structure is
formed by van der Waals
forces.
Elbow bend
tRNA has 4 loops. The most
important of them is the
anticodon. Anticodon, a three
nucleotide containing triplet,
determines the type of tRNA.
This triplet corresponds to the
mRNA codon on the principle
of complementarity.
64. Degradation of RNA depends of cell
needs.
If protein production is low, mRNA is
degraded more
65. PROTEIN SYNTHESIS PROCEEDS IN 4
STEPS
I. TRANSCRIPTION
II. Amino acid activation and recognition
III. TRANSLATION. It is a transfer of the
information from RNA to the structure of on
polypeptide chain of PROTEIN.
GENETIC INFORMATION IS TRANSMITTED by the
mechanism of the MATRIX.
IV. Post-translational processing
66. STAGES OF TRANSLATION
Translation comprises of 3 stages:
A) initiation, B) elongation, C) Termination.
Elongation proceeds from the N-end to the C-end in 3 stages :
1) Recognition of the codon. This stage ends with the connection of
aminoacyl tRNA with mRNA.
2) At Trans-peptidation, when a peptide bond is formed.
3) Translocation. It occurs when mRNA moves 1 triplet on the
ribosome to 3` end.
67. tRNA brings amino acids to A-center of ribosome. Formyl-
methionine is the first amino acid of synthesized peptide. It
enters P-center
68. CODONS ARE UNIVERSAL, i.e. they act
in all living organisms
In ribosome, Amino acyl (A), Peptidyl (P)
centers and Exit zone occur.
Synthesis starts with GUG or AUG triplet.
So, they are initiating codons.
The initiation codon is the codon of N-
terminal methionine (in procaryots – formyl-
methionine).
70. ELONGATION PROCEEDS IN 3 STAGES FROM N-END TO
C-END. There are three positions for tRNA in ribosome
Aminoacyl center called A-center, which is the binding site of an aminoacyl-tRNA with a
ribosome.
71. Amino acid is activated in 2 stages:
1st stage:
Mg2+
amino acid + АТP aminoacyl adenylate
2nd stage:
the formation of
aminoacyl-tRNA, i.e.
binding of amino acid to 3 ’-
OH end of tRNA.
72. tRNA binded to amino acid. Recognition of the codon leads to
the connection of aminoacyl tRNA with mRNA.
73. Terminal 3`OH-group of adenosine in
CCA triplet in accepting arm
tRNA CCA
(acceptor) end.
Adenine binds
amino acid
through 3`-OH
group
74. 2) TRANSPEPTIDATION -formation OF
PEPTIDE BOND
Each peptide bond is formed at the expense of 4 high energy bonds (2ATP, 2GTP).
Despite the fact that the peptide bond contains only 21 kJ of energy, 140 kJ of energy is
expended on its formation.
75. 3rd stage of translation, Translocation occurs when mRNA
moves 1 triplet on the ribosome to 3` end.
1) peptidyl-tRNA moved from the A-zone of ribosome to the P-
zone.
2) mRNA moves 1 codon on the ribosome in direction to 3`end,
3) tRNA leaves P-zone, then E-zone
E
A
P
76. 3) TRANSLOCATION in Translation- mRNA moves 1
triplet.
mRNA shifts 1 codon in 5`, 3` direction,
tRNA leaves P-site to leave the ribosome through Exit zone,
peptidyl-tRNA moves from A-zone to P-zone
with `Met
empty
2nd amino acid
GENERAL DIRECTION OF SYNTHESIS: 5` 3`
1st 2nd 3rd amino acid
4th amino acid
77. WHEN A TERMINATION codon includes into the A-SITE
of the ribosome, the RELEASING FACTOR BINDS TO THis
SITE and STOPS TRANSLATION
• TERMINATION is encoded by
UAA, UGA, UAG codons.
• Upon termination, the releasing factor binds
to the ribosome, after which ribosomal
complex and mRNA are separated.
FOR EACH PEPTIDE BOND WE SPEND 140KJ OF
ENERGY.
78. UAA encodes termination: thanks to p-protein,
ribosomal particles and protein are separated
When a termination codon (UAA, UGA, UAG. ) enters into the A site ,
a releasing factor (p-protein) binds to the site, stops the translation
and provides the releasing of the ribosomal complex and mRNA.
79. POST-TRANSLATIONAL MODIFICATION
(PROCESSING)
1)DEFORMYLASE cleaves formyl from formyl-methionine.
2)The N-terminal amino acid is acetylated.
3) Addition of glycosyl-, phosphate-, carboxyl-, hydroxyl-,
groups, iodine etc. occurs. Between cysteine molecules, disulphide
bond is made.
- Carbohydrates (glycosyl groups)are associated with serine,
threonine, asparagine.
- Phosphate binds to serine and threonine.
- 𝐴𝑑𝑑𝑖𝑡𝑖𝑜𝑛𝑎𝑙 carboxyl group binds with glutamic or aspartic
acids.
- Lysine and proline are hydroxylated.
4) The prostetic group is associated with its apo-protein part.
5) Partial proteolysis converts proinsulin to insulin, pro-
parathormone – to parathormone
80. REGULATION OF SYNTHESIS
CONSTITUTIVE PROTEINS are constantly synthesized in
the cell (for them, inductor is not needed)
INDUCTIVE PROTEINS NEED AN INDUCTOR FOR THEIR
SYNTHESIS. These proteis depend on the condition of
the life.
Anabolic drugs enhance the synthesis of proteins.
Hypoxantine –riboside, potassium orotate are non-
hormonal anabolics.
Antibiotics inhibit the synthesis of proteins