Name: catalytic rna: ribozymes in action
Uploaded: 2023-04-30T18:28:42.000Z
Duration: 2 min 47 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

NC K-12 Science Standard Course of Study

9-12

Biology

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms- Structures and Processes

LS.Bio.1.2

Ribozymes

Ribozymes are special types of RNA that can act as enzymes.&#160; &#160;
The substrates for most naturally occurring ribozymes are RNA phosphodiester bonds. The only known exception to this is the 23S ribosomal RNA in the bacterial ribosome which catalyzes peptide bond formation.
Ribozymes have been found in all types of organisms and are similar to protein-based enzymes, as they both increase the rate of reactions. Many ribozymes need metal ions, like magnesium, as co-factors for catalyzing reactions.
Some classes of introns can act as ribozymes. Introns are categorized into five distinct classes &#8211; nuclear mRNA, nuclear tRNA, archaeal, group one, and group two introns.
Group one and two introns are large ribozymes that are several hundred nucleotides long and are found in fungal and plant mitochondria, chloroplasts, bacteriophages, and eukaryotic viruses.&#160;
They can self-splice without the help of any proteins, whereas nuclear introns are spliced by the spliceosome, an RNA and protein-containing enzyme complex.&#160;&#160;
Small ribozymes are usually 50 to 150 nucleotides long and are self-cleaving nucleotide sequence motifs. These can be found in many RNA plant viruses, as well as the hepatitis delta virus, a human pathogen.&#160;
The replication process in these viruses produce long RNA carrying multiple units of the viral genome where each unit carries a small ribozymes like hammerhead. These regularly spaced hammerhead enzymes undergo self-cleavage resulting in breakage of the long RNA into individual genome segments.
Most ribozymes cleave their own nucleotide sequence; however, Ribonuclease P can cleave other RNA molecules.&#160; Ribonuclease P is found in some bacteria and processes precursor tRNA to generate a mature 5&#8217; end.
The naturally available ribozymes are known to catalyze a narrow range of reactions such as phosphoryl transfer in nucleic acids and peptide bond formation in proteins. Scientists have synthesized artificial ribozymes in the lab which can perform a wide range of reactions like carbon-carbon bond formation and oxidation-reduction reactions.

ribozymes

The term ribozyme is used for RNA that can act as an enzyme. Ribozymes are mainly found in selected viruses, bacteria, plant organelles, and lower eukaryotes. Ribozymes were first discovered in 1982 when Tom Cech&#8217;s laboratory observed Group I introns acting as enzymes. This was shortly followed by the discovery of another ribozyme, Ribonulcease P, by Sid Altman&#8217;s laboratory. Both Cech and Altman received the Nobel Prize in chemistry in 1989 for their work on ribozymes.
Ribozymes can be categorized into two groups depending upon their size &#8211; large and small. Large ribozymes can vary in size from a few hundred to several thousand nucleotides. The type I and II introns and bacterial Ribonuclease P are large ribozymes. Small ribozymes are 30 to 150 nucleotides long. They are found in many pathogenic plant viruses and the hepatitis delta virus (HDV), a human pathogen. Hammerhead, hairpin, HDV and Varkud satellite are common types of small ribozymes. Most large ribozymes need metal ions, especially Mg2+, for their activity, but metal ions are not necessary for most of the small ribozymes. The glmS ribozyme, in glmS mRNA, is a unique a-ribozyme as it also acts as a riboswitch when glucosamine 6-phosphate is present at high concentrations.
Most naturally occurring ribozymes catalyze self-cleavage breaking phosphodiester bonds present in their own RNA. Unlike a typical protein enzyme, most ribozymes perform a single-turnover reaction because, after self-cleavage, they are no longer active. However, two ribozymes - Ribonulcease P and the 23S RNA in the 50S ribosomal subunit perform different reactions. Bacterial Ribonuclease P is an RNA-protein complex that has endonuclease activity and requires Mg2+ ions. Its RNA component acts on the 5&#39; end of premature tRNA to produce the mature 5&#39; end. The 23S RNA present in the ribosome is different from all other known natural ribozymes as instead of phosphoryl transfer reactions, it carries out peptide-bond formation reactions during translation.
As RNA can act as a carrier of genetic information as well as enzymes, it is hypothesized that an &#8220;RNA world&#8221; may have existed in the past where RNA played an important role in the development of the early life forms.&#160; However, with the evolution of complex life forms, proteins with twenty amino acids might have started acting as enzymes and took over the many reactions carried out by the ribozymes. This theory gets support from the in-vitro developed artificial ribozymes that can carry out a myriad of reactions such as amide bond formation, glycosidic bond formation, carbon-carbon bond formation, and oxidation-reduction reactions.

The term ribozyme is used for RNA that can act as an enzyme. Ribozymes are mainly found in selected viruses, bacteria, plant organelles, and lower ...

Education

JoVE Core

Cell Biology

Unit 1

Energy and Catalysis

KEY TERMS AND CONCEPTS

catalytic rna: ribozymes in action

Ribozymes are RNA molecules that can act as enzymes. They help speed up specific chemical reactions without being protein enzymes. This makes them an important example of RNA with more than one job in the cell.

Some ribozymes can cut RNA molecules, and others can join them together. This shows that RNA can do catalytic work as well as carry genetic information. Ribozymes are a key part of how scientists think about the many roles of RNA in biology.

One well-known ribozyme is ribonuclease P, or RNase P. It helps process precursor tRNA into mature tRNA by removing extra RNA at one end. This process is important because tRNA must be correctly trimmed before it can function in protein synthesis.

Catalytic RNA: Ribozymes in Action

the first law of thermodynamics

Energy Changes in Cells and Matter

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the second law of thermodynamics

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endergonic-and-exergonic-reactions-in-the-cell

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the equilibrium binding constant and binding strength

the-equilibrium-binding-constant-and-binding-strength

How Equilibrium Binding Constant Affects Binding

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free energy and equilibrium

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oxidation-and-reduction-of-organic-molecules

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enzymes and activation energy

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turnover number and catalytic efficiency

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catalytically perfect enzymes

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introduction to mechanisms of enzyme catalysis

introduction-to-mechanisms-of-enzyme-catalysis

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ligand binding and linkage

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Ribozymes are RNA molecules that can act as enzymes. They help speed up specific chemical reactions without being protein enzymes. This makes them an important example of RNA with more than one job in the cell. Some ribozymes can cut RNA molecules, and others can join them together. This shows that RNA can do catalytic work as well as carry genetic information. Ribozymes are a key part of how scientists think about the many roles of RNA in biology. One well-known ribozyme is ribonuclease P,...

atp energy storage and release

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key terms and concepts

Explore ribozymes, RNA molecules that act as enzymes, cut or join RNA, and help process precursor tRNA into mature tRNA for protein synthesis.

Catalytic RNA: Ribozymes in Action | JoVE K12

cell biology

JoVE Core Cell Biology illustrates complex cellular processes in easy-to-understand yet comprehensive animated video lessons. This collection focuses on the essential components and functions of cells, including organelles and membranes, cellular transport, and cell energetics. It is complemented by scientist-in-action videos that demonstrate the application of cell biology in real-world research experiments.

Virginia  Standards of Learning

HIgh School

BIO.2

BIO.2.c

Florida Department of Education

High School

Life Science

SC.912.L.18

SC.912.L.18.4

SC.912.L.18.11

Texas Essential Knowledge and Skills

BIO.11

BIO.11.B

Compounds Essential to Human Function

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Macromolecules

Biomolecules
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lipid-derived-compounds-in-the-human-body

Lipid-derived Compounds in the Human Body

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Protein Denaturation

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Role of Proteins in the Human Body

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Nucleic Acid Structure

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ATP Energy Storage and Release

ATP and Macromolecule Synthesis

Biological macromolecules are organic compounds, predominantly composed of carbon atoms. The carbon atoms are covalently bonded with hydrogen, oxygen, ...

Construct an explanation to illustrate relationships between structure and function of major macromolecules essential for life.

LS.Bio.1.1

Introduction to Enzymes

The use of enzymes by humans dates to 7000 BCE. Humans first used enzymes to ferment sugars and produce alcohol without knowing that this was an ...

Enzymes and Activation Energy

The activation energy (or free energy of activation), abbreviated as Ea, is the small amount of energy input necessary for all chemical reactions to ...

Introduction to Enzyme Kinetics

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Turnover Number and Catalytic Efficiency

The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from ...

Catalytically Perfect Enzymes

The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at ...

Introduction to Mechanisms of Enzyme Catalysis

For many years, scientists thought that enzyme-substrate binding took place in a simple &#34;lock-and-key&#34; fashion. This model stated that the enzyme ...

Ligand Binding and Linkage

Cooperative Allosteric Transitions

Carry out investigations to illustrate how enzymes act as catalysts for biochemical reactions and how environmental factors affect enzyme activity.

What are Cells?

Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium or trillions of them, ...

Cell Size

Cell sizes vary widely among and within organisms. Bacterial cells range between 1-10 micrometers (&#x3BC;m)and are considerably smaller than most ...

Eukaryotic Compartmentalization

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry ...

Prokaryotic Cells

Prokaryotes are small unicellular organisms that include the domains&#x2014;Archaea and Bacteria. Bacteria include many common organisms, such as ...

Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Endoplasmic Reticulum

Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Golgi Apparatus

As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are ...

Lysosomes

Lysosomes are membrane-enclosed spherical sacs derived from the Golgi apparatus. The most important function of the lysosome is degrading macromolecules ...

Peroxisomes

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration&#x2014;the ...

Introduction to the Cytoskeleton

Overview of the Cytoskeleton
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Introduction to Actin

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Cell Structure

Background
Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, ...

overview-of-myosin-structure-and-function

Overview of Myosin Structure and Function

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Remove the entire brown outer skin and ...

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Types of Intermediate Filaments

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Gap Junctions

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Use models to explain how the structure of organelles determines its function and supports overall cell processes.

LS.Bio.1.3

Analyze how the relationship between structure and function supports life processes within organisms.

Catalytic RNA: Ribozymes in Action

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