Zebrafish

Zebrafish

Hi my name is Oeufie. I am an egg cell in the Model Organism, zebrafish. I am a specialised reproductive cell originating from meiosis in tissues in the ovary. My structure is a circular structure composed of a cell membrane, nucleus and yolk granules (also surrounded by a membrane). When I am fertilised with a sperm cell, I will become a zygote which would further divide into an embryo capable of growing into an entirely new organism.
Zebrafish is a model organism used to study embryonic development as they are encased by a transparent sac which allows researchers to see various stages of organ development. Added advantages include short generation time and also the large number of offspring produced.

Crossword

“The real question one should ask when presented with a puzzle is, ‘Should I solve it? Do I really need to know the answer?”

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Across

3. molecules with the same molecular formula but different structure, and therefore shape
6. insoluble in water, repels water, “water fearing”
9. a common monosaccharide
11. in plants, chains of glucose used for energy storage
13. polysaccharide that makes up plant cell walls
15. glucose plus fructose = 
16. type of bond that holds amino acids together
18. general term used to describe molecules that have a carbon skeleton and some hydrogen atoms
19. polysaccharide that makes up the exoskeleton of insects
21. macromolecule consisting of covalently bonded monomers

 Down

1. synthesis where water is removed and two compounds bond together
2. type of fatty acid that has all single bonds (solid at room temperature)
4. milk sugar
5. an important component of cell membrane
7. class of organic compounds consisting of carbon, hydrogen, and oxygen atoms; includes monosaccharides, disaccharides, and polysaccharides
8. composed of one or more chains of amino acids
10. the number of electrons in carbon’s outer shell
11. type of liped that has four interlocking rings, examples are cholesterol, estrogen and testosterone
12. the splitting of a compound by the addition of water
14. organic catalyst, usually a protein molecule that speeds reactions
17. in animals, long chains of glucose used for energy storage
20. monomer of DNA an RNA, consists of a 5 carbon sugar, a nitrogen containing base, and a phosphate group

Lipids

Lipids have various roles such as energy storage, structural role in cell membrane as the phospholipid bilayer, steroid hormones and messenger molecules.
Lipids are highly hydrophobic (water hating) and is soluble in organic solvent.
There are various classifications of lipids including the following:
-Triglyceride
-Phospholipids
-Glycolipid
-Steroids
-Carotenoids

This video was very educating and the only improvement I can suggest is a typed clear font rather than handwriting or larger diagrams.

The Mind of A Psychopath

Kiehl, Kent and Joshua W. Buckholtz. (2010). Inside the Mind of a Psychopath.

http://www.nature.com/scientificamericanmind/journal/v21/n4/full/scientificamericanmind0910-22.html

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Looks can be deceiving…

The Mind of Psychopath

Psychopaths suffer from a mental disorder whereby they usually express amoral and antisocial behavior, emotional impairment and also failure to recognize errors.  Various studies have found dysfunction in specific parts of the psychopathic brain such as the amygdala, orbitofrontal cortex and the paralimbic system among others. These would explain the behaviors exhibited by psychopaths. Other research suggests genetics and environment are responsible for psychopathic behavior, particularly in extreme cases.

The amygdala is an almond-shaped bunch of nuclei found deep within the temporal lobe of the brain. It is responsible for the feeling of fear, anxiety and anger. When this malfunctions, there is little stimulation to produce the feeling of fear. The orbitofrontal cortex is one of the prefrontal lobes in the cortex region that is responsible for decision making and certain social behaviors and when this is damaged, impulsive behavior is evidently present.

Additionally the paralimbic system consists of the anterior cingulate cortex and also the insula. The anterior cingulate cortex is responsible for regulating emotional states, impulse control and regulating mistakes in behavior. When this is malfunctioning, persons cannot determine emotions from facial expressions for themselves and also are unable to recognize abnormal behaviors expressed.  The insula however is responsible for monitoring social norms, emotions of anger, disgust, fear and empathy and also in pain perception. Damage to this region results in persons being able to tolerate pain far greater than others and are socially awkward in terms of being unable to empathize, and able to withstand repulsive images and scents.

However recent research has indicated that psychopathy may be due to the genetic make-up or the environment of an individual.  This can indicate that psychopathy can either be nature or nurture in that individuals may be born psychopaths or they can develop into psychopaths based on the environment they develop in.

Even with recent behavioral studies, the minds of psychopaths are still unclear as there are always unique cases that go against what scientists determine.

Additional References

Blair, R.J.R. (2003). Neurobiological Basis Of Psychopathy. The British Journal of Psychiatry.

Blair, R.J.R. (2008). The Amygdala and Ventromedial Prefrontal Cortex: Functional

Contributions and Dysfuntion in Psychopathy. Royal Society Publishing.

Blonigen, Daniel, Brian M. Hicks, Robert F. Krueger, Christopher J. Patrick, And William G.

Iacono. (2005). Psychopathic Personality Traits: Heritability And Genetic Overlap With

Internalizing And Externalizing Psychopathology. Minnesota, USA: University of Minnesota.

Kiehl, K.A. (2006). A Cognitive Neuroscience Perspective on Psychopathy: Evidence for 

            Paralimbic System Dysfunction. Hartford, USA: Olin Neuropsychiatry.

Rolls, ET. (2004). The Functions Of The Orbitofrontal Cortex. England, UK: University of

Oxford.

White, S. (2001). Making a Monster: The Biological, Social, and Artistic Construction of a

Serial Killer. From Psychosis to Sondheim.  :http://www.serendip.brynmawr.edu//bb/neuro/neuro01/web3/white.html

MCQ questions!

1) In the conversion of glucose to pyruvate, how many enzymes are involved and what is the net ATP gained?

  1. 10 enzymes, 4 ATP molecules
  2. 9 enzymes, 4 ATP molecules
  3. 10 enzymes, 2 ATP molecules
  4. 9 enzymes, 2 ATP molecules
  5. 11 enzymes, 4 ATP molecules

2) Choose the correct answer based on the following key:

  1. I, III correct
  2. None are correct
  3. III, IV correct
  4. I, II, III correct
  5. All are correct

Where is NAD+ reduced to NADH + H+ in the TCA cycle?

I.            Citrate   ——>        isocitrate

II.            fumarate   ——>    malate

III.            Alpha-ketogluterate  ——>     succinyl CoA

IV.            Malate    ——>    oxaloacetate

V.            Succinate        ——>    fumarate

Enzyme Inhibition

This video describes the various inhibition of enzymes such as competitive, non-competitive and uncompetitive inhibition.
It shows where the inhibitor affects and the Lineweaver–Burk plots obtained for each inhibition.
The video can be improved in terms of audio as some sound is distorted and in terms of visual, with the aid of computerized graphs so it can be clearer.