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BIOLOGY Lecture Notes - Gastrulation, Triploblasty, Blastula

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wezelbarcelon06
10 Dec 2022
School
Eastern Samar State University
Department
Earth Science
Course
BIOLOGY
Professor

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Document Summary

Gastrulation is the process that occurs during embryonic development transforms the blastula into an embryo with a single layer of cells. Gastrulation is typically caused by the blastula folding in on itself or dividing, resulting in two layers of cells. Diploblastic organisms are those that do not have a third layer. Jellyfish and other animals fall into this category. The mesoderm, which is formed from one of the first two layers, is found in triploblastic organisms. The majority of higher animals are triploblastic. The layers, or special tissues, give rise to specific organisms. organs. Gastrulation produces germ layers, which are special tissues that give rise to specific parts of the organism. Even in different animals, these germ layers always give rise to the same types of tissues. The blastoderm contains approximately 20,000 cells by the time a hen lays an egg.

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Related Questions

Please try to complete lab asap. Due at 11.59pm. 1/2 parts 

 After having watched the video titled "DNA The Secret of Life" and the assigned link below: - as well as what our Science Specialist, Ms Tiarra Thompson performs in the Blended Lab:-

https://www.youtube.com/watch?v=yvaAW43sQNo
as well as what our Science Specialist, Ms Tiarra Thompson performs in the Blended Lab in Echo 360:-
Use Chargaff's Rules to Transcribe and Translate this DNA Strand :- A T T C C G G G G A A T TC G C G A T A T A T C C C G A G A G A C A C A T T T A A A C C C A T A T A T T T C G G C G C C C C A T C G C G A C G C TT A A A C C C C G G C
=> Once RNA has completed the Transcription process, and the Translation of the mRNA/Codon/Triplet is completed using as class discussion, as well as your knowledge and Figure 12:5, list your amino acids and finally research to indicate their individual functions of the amino acids in life or in an organism. A table similar to the one below will be helpful greatly:-

What are prions?

In cell, there are subcellular organelles. They are not full organism. Prions are just proteins. They don't have any other macromolecules. Prions have capacity to form copies through replication. They replicate through free radical and chain mechanism. 

Doctor Stainly pruisne work on prions and show it's relation with disease called mad cow disease. ( This is neurodegenerative disease and responsible for harmful effects on brain).

In Australia sheep was infected with prions, caused scarpie disease in sheep. Organs of sloghed sheep were used in cow feedd. When cow consume feed, prions were transmitted to cow and cow start to show unusual behavior.

Symptoms of prions infection are like that of some disease 

  1. Kurulyprosy
  2. Insomnia
  3. Dimensia

Detection of prions: Prions can be detected by Western bloting.

Normal prions:

Normal prions are present in our body. They don't have tendency to form rigid aggregate. They are quite less in number. They have following functions

  1. Cellular differentiation
  2. Store elemental surplus that is used in future
  3. Memory enhancement

Molecular basis of prions:There is some difference in structure of Normal and abnormal prions.

  1.  Normal prions have molecular weight 33-35KD while abnormal prions have molecular weight 27-30KD
  2. In normal prions at position 178 amino acid aspartate is present while in abnormal prions at 178 position asparagine is present. 

Prions diagnosis and analysis:

  1. Brain biopsy....in past for taking sample brain biopsy was used but now a days tonsils biopsy is used for sampling.

Immuno fluorescence:Biopsy sample is taken on slide and it is treated with antibody ( of abnormal prions) which is against normal prions. Speciality of antibody is that when it bind with abnormal prion it will glow. If we capture fluroscene it's mean abnormal prion is present in sample. As abnormal prion antibody was label with fluroscene probe. So patient sample will show fluroscene while normal sample will not show fluroscene.

Transmission of prions: Normally prions can't Cross specie barrier they transmitted through different ways. Like as formite

If a person is effected with prions and he has wound in head and his comb is used by another person so prions can be transferred to other individual. Comb is Carrier of prion.

Prions are very slow acting immune system can't destroy them.

 

 

Do Enzymes Physically Attach to Their Substrates?
 
When scientists first began to examine the chemical activities of organisms, no one knew that biochemical reactions were catalyzed by enzymes. The first enzyme was discovered in 1833 by French chemist Anselme Payen. He was studying how beer is made from barley: First, barley is pressed and gently heated so its starches break down into simple two-sugar units; then yeasts convert these units into ethanol. Payen found that the initial breakdown requires a chemical factor that is not alive and that does not seem to be used up during the process-a catalyst. He called this first enzyme diastase (we call it amylase today).
 
Did this catalyst operate at a distance, increasing the reaction rate all around it, much as raising the temperature of nearby molecules might do? Or did it use physical contact, actually attaching to the molecules whose reaction it catalyzed (its "substrate")?
 
The answer was discovered in 1903 by French chemist Victor Henri. He saw that the hypothesis that an enzyme physically binds to its substrate makes a clear and testable prediction: In a solution of substrate and enzyme, there must be a maximum reaction rate. When all the enzyme molecules are working full tilt, the reaction simply cannot go any faster, no matter how much more substrate you add to the solution. To test this prediction. Henri carried out the experiment whose results you see in the graph, measuring the reaction rate (V) of diastase at different substrate concentrations (S).
 
Analysis
1. Making Inferences As S increases, does V increase? If so, in what manner-steadily, or by smaller and smaller amounts? Is there a maximum reaction rate?
2. Drawing Conclusions Does this result provide support for the hypothesis that an enzyme binds physically to its substrate? Explain. If the hypothesis were incorrect, what would you expect the graph to look like?
3. Further Analysis If the smaller amounts by which V increases are strictly the result of fewer unoccupied enzymes being available at higher values of S, then the curve in Henri's experiment should show a pure exponential decline in V-mathematically, meaning a reciprocal plot (1/V versus 1/S) should be a straight line. If some other factor is also at work that reacts differently to substrate concentration, then the reciprocal plot would curve upward or downward. Fill in the reciprocal values in the table to the right, and then plot the values on the lower graph (1/S on the x axis and 1/V on the y axis). Is a reciprocal plot of Henri's data a straight line?