Communication among other cells of Zebrafish

With respect to the interactions of cells in the zebra fish, 3 cells types were studied: 1) Hair cells (group members- Stefan Sooklal, Riaz Lourenco, Sanjeev Teelucksing) 2)Brain cells (group members- Deanna Deonarine, Shivana Narine, Kelsey Ramkhelawan, Celine Jahori) and 3)cardiac muscle cells (group members- Vera Julal, Stefan Rajaram). The interactions involve the hair cells picking up a signal in response to a stimuli such water movement and vibrations, which then sends this signal to the brain, in which the brain interprets and evokes a response. This response message is then sent to the cardiac muscle cells which brings about the response, and hence the communication reaction is complete.
These conditions for this type of cell communication is only brought about due to responses from water movement and vibrations, such as movement of predators and prey as well as changes in currents. Basically for these communication to take place certain conditions must be met. In this case, it requires shallow water and stagnant water. Because of this, any slight movement can be detected by the zebra fish which brings about the communication cycle among cells.
For this type of interaction to occur, it is initiated by the slightest movement within its habitat, which is detected by the hair cells. Once this signal is received by the hair cell of the zebra fish, the communication of cells begins.
To fully understand the “hits” of long distance cell to cell communication, we analyze the predator-prey relationship of the zebra fish. For instance, if a said predator is nearby, there would trigger water movements in water which will be detected by the hair cells. This results in the hair cells being horripilated (erected). This voluntary response then sends a signal to brain cells ( HIT 1). The signal is then interpreted in brain cells. The brain cells comprehend the fact that a predator is near and send the necessary signals to other cells that can instigate a defense mechanism. Once such cells receives a message is the cardiac muscle cell ( HIT 2).The cardiac muscles then causes muscle cells to contract and relax. These movements increase heart rate, and allow fast blood flow throughout the body and muscle. This then delivers more oxygen via blood cells to muscles cells (HIT 3). This allows the sufficient amount of oxygen that is need for ATP production in respiration that will be required for the muscles to work efficiently and hence allow the zebra fish movements to be swift and allow escape from the predator.
Overall the end of the interactions, deals with the relaxation of the hair cells as there is no movement in the water, so no messages are sent to brain and no messages sent to the cardiac muscle cell, hence the contraction and relaxation of cardiac muscle is reduced and hence heart rate is reduced, thereby ending the communication cycles of cells.
Capture

By stefbiochem

Importance of Communication for Development in Zebrafish

With respect to communication among lateral line hair cells, these cells communicate via reveal synaptic communication which involves the use of Afferent neurons synapse. Communication is established between hair cells of a given polarity and the afferent neurons. A stimuli enters hair cells by passing directly through mechanically gated transduction channels on the stereocilia and subsequently permeates to the afferent neurons, but may be blocked when the mechanotransducing channels are closed.

The lateral line hair cells are said to interact with the neighboring cells such as the KINOCILIUM. The kinocilum is A special type of cilium on the apex of hair cells located in the sensory epithelium kinocilia are found on the apical surface of hair cells and are involved in both the morphogenesis of the hair bundle and mechanotransduction.. With respect to the communication between the hair cell and the kinocilium, the kinocilium is said to respond to Vibrations that cause displacement of the hair bundle, resulting in depolarization or hyperpolarization of the hair cell. The depolarization of the hair cells in both instances causes signal transduction via neurotransmitter release. This results in the movement of the entire hair bundle, which will cause will cause potassium channels on the stereocilia o the hair cell to open. This depolarization will open voltage gated calcium channels and the depolarization of the hair cell causes neurotransmitter to be released and an increase in firing frequency of cranial nerve VIII. Hence the communication process is complete.

Diagram of a lateral line hair cell

By stefbiochem

ZEBRAFISH!!!!

The model organism is choose to study is the ZEBRAFISH.

A zebra fish

What is a model organism?

Model organisms are those that useful data sets have been already gathered to describe basic biological processes. A model system is a simpler system that can be acquired and easily manipulated.The characteristics common to model organisms, include 1) rapid development with short life cycles, 2) small adult size, 3) ready availability, and 4) tractability. There are three advantages to using model organisms in teaching biology. Firstly in a laboratory setting, the model organism’s immediate response to the change of environment will generate observations. Secondly, it involves hands-on experience. Thirdly, by working with model organisms, students are able to explore scientific methods and concepts.

The cell I am researching from the Zebrafish are the LATERAL LINE HAIR CELLS

Diagram of a lateral line hair cell

INTRODUCTION ON THE LATERAL LINE HAIR CELLS

Lateral Line hair cells are said to orginate in thickened sensory patches, where they are anchored in a pseudostratified epithelium, and are found distributed with supporting cells, which spread throughout the epithelium. The purpose of the lateral-line hair cell is to detect water movement and vibration and is important in detection of predators and prey. With respect to the aging of the these hair cells, they usually diminish in number due to cells being damaged. However, hair cells in the zebrafish lateral line regenerate rapidly and completely after damage. Damage to hair cells is result of with many factors, including exposure to various drugs, loud noise, and age-related degradation

STRUCTURE OF THE LATERAL LINE HAIR CELL.

Hair cells have a well-defined apicobasal polarity, with specialised cytoskeletal structures on their apical surfaces. These consist of a bundle of stereocilia, arranged in a stepped array, and a single kinocilium. Stereocilia and kinocilia are embedded in the otolithic membrane or a gelatinous cupula. Stereocilia vary in number and length, depending on the type of sensory patch. The location of the kinocilium relative to the stereocilia gives each hair cell a polarity in the plane of the epithelium. Hair cells synapse with afferent and efferent neurons are on their basal surfaces.

layout of the zebra fish w.r.t. lateral hair lines

By stefbiochem

Published paper 2!!

“Nerve agents.” http://www.pdhealth.mil. N.p., n.d. Web. 31 Mar. 2013. .

Nerve agents

Nerve agents are weapons that are used in chemical warfare, such as tabun, sarin, soman and cyclosarin. There are usually volatile at room temperature and have greater density than air.
Nerve agents function by the inactivation of the enzyme/ phosphorylating acetylcholinesterase (AChE). The nerve agent binds to AchE and the chemical bond is formed resulting in the accumulation of acetylcholine (ACh) at receptors at nerve synapses, as well as receptors in the central nervous system (CNS). This leads to diarrhea, frequent urination, and salivation. Other symptoms include nausea, vomiting, eye pain, blurred vision, muscle pain, tremors, weakness, hypertension, headache, agitation, confusion, vertigo, decreasing consciousness, seizures, as well as coma. The combination of these effects can cause acute and fatal respiratory failure muscle paralysis, and CNS mediated depression of the respiratory drive.
The diagnosis of nerve agent exposure is done by drawing blood for red blood cell AChE activity. If this red blood cell AChE is reduced by 70%, the test is positive.
For treatment of nerve agent exposure, two antidotes are used 1) pralidoxime and 2) atropine. One is usually incubated and put under ventilation to control the airway, as there is usually muscle weakness, causing respiratory difficulty. Side effects of this antidotes include seizures and respiratory infection.
Recovery from nerve agent poisoning is the most crucial. There is a delayed response syndrome which is usually temporary but may also result in the re-initiation of respiratory incubation. Some usually experience muscle paralysis after recovery, as most of the nerve were damaged due to exposure to the nerve agent. As a result of nerve damage, blurry version occurs and in a worst case scenario blindness occurs.

By stefbiochem

Published paper part 1

Hamel, Jillan. “A Review of Acute Cyanide Poisoning With a Treatment Update .”
Critical Care Nurse. http://ccn.aacnjournals.org/content/31/1/72.full (accessed March 31, 2013).

Acute Cyanide Poisoning With a Treatment update

Cyanide can be found in many household item, such as wool and which contain carbon and nitrogen and may release cyanide gas when exposed to high temperatures. Constant exposure to cyanide gases, result in increase in cyanide concentration within the blood and hence causing cyanide poisoning, Cyanide can also be used in the industry for the use of electroplating of metals. These cyanide salts the produce hydrogen cyanide gas with the presence of acids, hence resulting in cyanide poisoning. . Left untreated, it can result in illness and death.

Cyanide is poisonous as it diffuse into the tissues and connects to target site immediately and symptoms occur quickly. One of the most common sources of cyanide poisoning, is from smoke inhalation from structural fires. Cyanide poisoning occurs from improper functioning of the cyanide metabolism, causing an accumulation of thiocyanate. The accumulation of thiocyanate is due to the fact that the enzyme rhodanese, from the liver, does not catalyze all the cyanide to thiocyanate. The thiocyanate then gathers in the kidney causing impaired renal function, due to the high toxicity, hence the body is unable to excrete thiocyanata at the proper rate, resulting in cyanide poisoning.

Upon inhalation of cyanide gas one can develop anxiety, headaches and lack of focus. Further progression of cyanide poisoning one may experience skin ashening, rapid and deep respirations. It also affects the cardiovascular system such as vasodilatation , hypotension, increase in arrhythmias, bradycardia, heart block and cardiac arrest.

For treatment of cyanide poisoning one must determine the cause of exposure of cyanide gas to be given to proper antidote. A person health status is also a factor in determining the correct antidote. These antidotes include 1) cyanide antidote kit and 2) hydroxocobalamin.

The cyanide antidote kite contains 3 medications given together for their combined effect. When it is administered, great attention is paid to the patient as vasodilatation and hypotension may occur. Basically, the cyanide antidote kit, restores the proper functioning of the enzyme rhodanese. However, Hydroxocobalamin detoxifies cyanide by combining with it to form, nontoxic cyanocobalamin. Cyanocobalamin diffuses cyanide at a rate that is adequate enough to permit the enzyme rhodanese to detoxify the cyanide in the liver. Hence they both convert cyanide.

By stefbiochem

Glycolysis Quiz

Based on what u have u learned on this topic you should be able to answer the following question. Good luck!!!!

1)Which of these enzyme reactions is not irreversible in glycolysis?
a) Hexokinase
b) aldolase
c) phosphoglycerate kinase
d) Phosphofructokinase-1
e) Pyruvate kinase

2)Select the correct multiple answer using ONE of the keys A, B, C, D or E as follows:
a) 1, 3 and 4 are correct
b) 1 and 3 are correct
c) 2 and 4 are correct
d) only 4 is correct
e) all are correct

Which of the following enzymes are involved in the prepartory phase of gylcolysis:
1)aldolase
2)enolase
3)hexokinase
4)phosphohexose isomersase

By stefbiochem

Glycolsis lectures and Summary of Glycolysis


Glycolysis is the conversion of glucose to pyruvate. It is universal meaning is its a process done by bacteria, yeast and humans. It involves two stages 1) Energy investment stage and 2) Energy generation stage, each of which involves 5 enzyme reactions, Giving a total of 10 enzyme reactions

Energy investment stage

Energy generation stage
Glycolysis 2

overall the net gain is 2ATP AND 2NADH

THE FATE OF PYRUVATE

Metabolism of Fructose
1)in the adipose tissue, muscle and kidney – hexokinase can phosphorylate fructose to fructose-6-phosphate that the enters glycolsis.
2)in liver – glucokinase enzyme is presnt instead of hexokinase and doesn’t phosphorylate fructose. fructose is metabolized by frcutose-1-phosphate pathway

metabolism of Galactose

TCA Steps

By stefbiochem

Enzyme wordle!!!! and Enzyme quiz

Capture

Below are some questions bases on what we have learned on Enzymes good luck!!!

1)All of the following are characteristic of enzymes expect :
a)very specific ie catalyze one type of reaction
b)globular proteins
c)enzyme catalyzed reactions are irreversible
d)lower the activation energy of a reaction
e)enzyme is left unchanged after the reaction

2)Select the correct multiple answer using ONE of the keys A, B, C, D or E as follows:
A. 1, 3 and 4 are correct
B. 1 and 3 are correct
C. 2 and 4 are correct
D. only 1 is correct
E. all are correct

Which of the following can affect enzyme activity
1)temperature
2)light
3)pH
4)Substrate concentration

By stefbiochem

Enzyme summary part 3

Inhibition of Enzymes
any substance that can diminish the velocity of an enzyme catalyzed reaction is called an inhibitor. Irreversible inhibitors bind to the enzymes through covalent bonds. Reversible inhibitors bind to the enzyme through non-covalent bonds.

Types of inhibition
1)competitive
2)non-competitive
3)uncompetitive
4)mixed

Competitive Inhibition
occurs when the inhibitor binds reversibly to the same site that the substrate would normally occupy and therefore, competes with the substrate for that site.

Non- competitive inhibition
This type of inhibition is recognized by its characteristics effect on Vmax. Occurs when the inhibitor and the substrate bind at different sites on the enzymes.

Uncompetitive inhibition
the inhibitor binds only to the enzyme substrate complex, at separate site from the substrate active site and not with the free enzyme.

mixed inhibition
when inhibition binds at a separate site from the substrate active site, to either the free enzyme or the enzyme-substrate complex. It resembles the non-competitive inhibition.

By stefbiochem