Signal Recognition Particle
1:24
This Maya animation depicts the process by which the translating ribosome is halted by the signal recognition particle (SRP). The ribosome is subsequently brought to the membrane and docked with a channel to translocate the nascent polypeptide chain.
video by Eric Keller, Steve Davy / Stylus Visuals
srp
Added: 367 days ago by
sertan
Views: 25514
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Reovirus Life Cycle
3:12
a more in-depth look at the reovirus life cycle. This current version highlights each of the 8 proteins that make up the virus as well as its icosahedral symmetry. The virus is activated upon chymotrypsin 'attack' and cleavage of the outer protein layer. The virus then binds to and enters the cell via the JAM-1 receptor and clathrin-mediated endocytosis.
video by Gael McGill, Janet Iwasa
reovirus
Added: 367 days ago by
sertan
Views: 19060
Comments: 0
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Muscle Contraction
0:42
A muscle contraction (also known as a muscle twitch or simply twitch) occurs when a muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten or remain the same. Though the term 'contraction' implies a shortening or reduction, when used as a scientific term referring to the muscular system contraction refers to the generation of tension by muscle fibers with the help of motor neurons. Locomotion in most higher only through the repeated contraction of many muscles at the correct times. Contraction is controlled by the central nervous system (CNS), which comprises the brain and spinal cord. Voluntary muscle contractions are initiated in the brain, while the spinal cord initiates involuntary reflexes.
contraction
Added: 282 days ago by
mnazirokur
Views: 17100
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Activated T Cells attacking on cancer cells.
0:39
t cell
This video shows activated T cell which are shiny blue and attacting on the cancer cells and kill them.
Video REf: http://www.hybridmedicalanimation.com
ppar
Added: 637 days ago by
benchwork
Views: 13891
Comments: 1
(3 ratings)
Bacterial Conjugation
0:14
Conjugation
Antibiotic resistance genes can be shared between bacteria through a sex pilus. Video Ref: www.learner.org
Video Reff: www.learner.org
Bacterial Conjugation text info: Bacterial conjugation is the transfer of genetic material between bacteria through direct cell-to-cell contact. Discovered in 1946 by Joshua Lederberg and Edward Tatum, conjugation is a mechanism of horizontal gene transfer as are transformation and transductionalthough these mechanisms do not involve cell-to-cell contact. text reff: wikipedia
Bacterial
Conjugation
Added: 641 days ago by
sana
Views: 12959
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ATP synthase structure and mechanism
3:19
ATP synthase
An ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phosphate by utilizing some form of energy. The overall reaction sequence is:
ADP + Pi → ATP
Molecular model of ATP synthase by X-ray diffraction method
ATP synthase in E. coliThese enzymes are of crucial importance in almost all organisms, because ATP is the common "energy currency" of cells.
In mitochondria, the F1FO ATP synthase has a long history of scientific study. The F1 portion of the ATP synthase is above the membrane, the FO portion is within the membrane. It's easy to visualize the FOF1 particle as resembling the fruiting body of a common mushroom, with the head being the F1 particle, the stalk being the gamma subunit of F1, and the base and "roots" being the FO particle embedded in the membrane. The F1 particle was first isolated by Ephraim Racker in 1961. The nomenclature of the enzyme suffers from a long history. The F1 fraction derives it name from the term "Fraction 1" and FO (written as a subscript "O", not "zero") derives it name from being the oligomycine binding fraction. Taking as an example the nomenclature of subunits in the bovine enzyme, many subunits have Greek and Roman alphabet names (alpha, beta, gamma, delta, epsilon and a, b, c, d, e, f, g, h), while others have more complex names such as F6 (from "Fraction 6"), OSCP (the oligomycin sensitivity conferral protein), A6L (named for the gene that codes for it in the mitochondrial genome) and IF1 (inhibitory factor 1).
The F1 particle is large and can be seen in the transmission electron microscope by negative staining (1962, Fernandez-Moran et al., Journal of Molecular Biology, Vol 22, p 63). These are particles of 9 nm diameter that pepper the inner mitochondrial membrane. They were originally called elementary particles and were thought to contain the entire respiratory apparatus of the mitochondrion, but through a long series of experiments, Ephraim Racker and his colleagues were able to show that this particle is correlated with ATPase activity in uncoupled mitochondria and with the ATPase activity in submitochondrial particles created by exposing mitochondria to ultrasound. This ATPase activity was further associated with the creation of ATP by yet another long series of experiments in many laboratories.
The antibiotic oligomycin inhibits ATP synthase.
Text Reff: http://en.wikipedia.org/wiki/ATP_synthase
atpsynthase
Added: 650 days ago by
benchwork
Views: 11918
Comments: 1
(6 ratings)
DNA - acridine complex structure
1:5
DNA fragment complexed with acridine derivative (a carcinogenic dye). Data source: Protein Data Bank code 2GB9.
Wiki text info: Acridine, C13H9N, is an organic compound and a nitrogen heterocycle. Acridine is also used to describe compounds containing the C13N tricycle.
Acridine is structurally related to anthracene with one of the central CH groups is replaced by nitrogen. Acridine, a colorless solid, was first isolated from coal tar. It is a raw material used for the production of dyes and some valuable drugs. Many acridines also have antiseptic properties such as Proflavine. Acridine and related derivatives bind to DNA and RNA due to their abilities to intercalate. Acridine Orange (3,6-dimethylaminoacridine) is a nucleic acid-selective metachromatic stain useful for cell cycle determination.
acridine
Added: 475 days ago by
adamsan
Views: 10855
Comments: 0
(1 ratings)
3D structure of chromosome
1:46
This video shows the packaging of DNA in the nucleus.
3D
struct
of
nuc
chroms
Added: 656 days ago by
benchwork
Views: 10539
Comments: 0
(4 ratings)
Protein synthesis
0:0
all
How are proteins synthesized? This interactive animation will help you to understand the process. For more information about protein synthesis:
Legend:
Process whereby DNA encodes for the production of amino acids and proteins.
This process can be divided into two parts:
1. Transcription
Before the synthesis of a protein begins, the corresponding RNA molecule is produced by RNA transcription. One strand of the DNA double helix is used as a template by the RNA polymerase to synthesize a messenger RNA (mRNA). This mRNA migrates from the nucleus to the cytoplasm. During this step, mRNA goes through different types of maturation including one called splicing when the non-coding sequences are eliminated. The coding mRNA sequence can be described as a unit of three nucleotides called a codon.
2. Translation
The ribosome binds to the mRNA at the start codon (AUG) that is recognized only by the initiator tRNA. The ribosome proceeds to the elongation phase of protein synthesis. During this stage, complexes, composed of an amino acid linked to tRNA, sequentially bind to the appropriate codon in mRNA by forming complementary base pairs with the tRNA anticodon. The ribosome moves from codon to codon along the mRNA. Amino acids are added one by one, translated into polypeptidic sequences dictated by DNA and represented by mRNA. At the end, a release factor binds to the stop codon, terminating translation and releasing the complete polypeptide from the ribosome
Text Reff: http://www.accessexcellence.org/RC/VL/GG/protein_synthesis.html
proteinsynthesis
Added: 646 days ago by
tubeman
Views: 10496
Comments: 2
(7 ratings)
Stem Cells Part I
1:27
Stem Cells
Stem cells serve as the source of all the other specialized cells in the body, both when it forms during embryogenesis and when it replaces cells that have been lost to aging, injury or disease. These videos are created by RIKEN CDB and they explain the different types of stem cell found in the embryonic body and the adult and illustrate the roles of these "master cells" in development and regeneration. Video REff: http://www.cdb.riken.go.jp
I also uploaded other 3 parts. Search " stem cells" on DnaTube and most probably you will find other videos.
stemcell
Added: 645 days ago by
siere
Views: 10442
Comments: 2
(5 ratings)
