Apr 13 2013

Puzzle Timeeee!! – THE CELL 


P M P F A C H S U S C H S V U 
R U X H J E O A U I G D G N C 
O R T V W P E E T L R W W A B 
T M D Z C R L O F U W D A R P 
E Y X O O C Y M V U P T N N Z 
A C B B U R F D X U W Z G U F 
S E I N A E U K A R Y O T I C 
E C A K I Q Q G I E R K G R H 
S N O P T E F C Y R L L Z O O 
D R H W A S G B V N P A O I E 
P C G D S C O N Y R K K O L K 
M I C R O S C O P E E Q P I V 
H Z S E M O S O S Y L P B P G 
S Y M B I O T I C A R E N O M 
M H N G S I P X G F P D D F W

 

AEROBIC

DNA

LYSOSOMES

EUKARYOTIC    

HOOKE

 MICROSCOPE

MONERA

NUCLEUS

PILI

PROKARYOTIC

PROTEASES

SYMBIOTIC

Apr 12 2013
Video

Mr. Krebs !!!!! :)

 

Heyy !!! 🙂

We’re just going to briefly chat about the Krebs Cycle, so that we all understand …lol

I chose this diagram in particular so that we can see the changes in the number of carbons also.
In Kreb’s Cycle also known as the citric acid cycle, two molecules of pyruvic acid from glycolysis are used and high energy is yielded.
This reaction occurs in the inner membrane of the mitochondrion.

However, before entering, each 3 carbon pyruvic acid is converted to acetyl coenzyme A.
Acetyl coenzyme A then binds to Oxaloacetic acid to form a 6carbon molecule, citric acid. From here on, THE GAMES BEGIN!!!!!!

References;
“Biology: Krebs Cycle .” Get Homework Help with CliffsNotes Study Guides . http://www.cliffsnotes.com/study_guide/Krebs-Cycle.topicArticleId-8741,articleId-8603.html (accessed April 13, 2013).

“Cellular Respiration Part 2: The Kreb’s Cycle – YouTube.” YouTube. http://www.youtube.com/watch?v=ncEHa-ZwX3M (accessed April 13, 2013).

By dsampson27
0
Apr 11 2013
Video

Video Review #2: Enzymes!

The video was quite short and knowing how lengthy the topic of enzymes is it was foreseen that the video would not have covered all that is necessary for university students. It would not have been helpful to even CAPE Biology students. It was just too basic with no real depth of information for the topic. Also there were no diagrams, though creative with the introduction and conclusion , the topic demands diagrams and its absence excluded the actual chemistry and general basis of the molecule. However, some examples given were good for comparison and reminders of some of the simple pointers that must be remembered. Aspects of the structure of enzymes, the chemical equations involved, graphs of the pathway and factors such as inhibition, temperature, pH, enzyme concentration and substrate concentration were all excluded, thus, making the video very vague and uninformative.

To improve this video the publisher shouldn’t be too mindful of the time period of the video and take a few more minutes to properly present the data so that even persons from higher levels of education can use it for at least light revision or to clarify the simpler aspects of enzymes. Diagrams, graphs and chemical equations are critical tools to assist with learning the topic and should therefore be used efficiently.


References:
“Learn Biology: Cells—Enzymes – YouTube.” YouTube. http://www.youtube.com/watch?v=feik6wOXFA0 (accessed April 11, 2013).

Melrose, Kevin. “Cartoon Network Abruptly Pulls DC Nation From October Lineup « Spinoff Online – TV, Film, and Entertainment News Daily.” Spinoff Online – TV, Film, and Entertainment News Daily. http://spinoff.comicbookresources.com/2012/10/13/cartoon-network-abruptly-pulls-dc-nation-from-october-lineup/ (accessed April 11, 2013).

Apr 11 2013
Video

VIDEO Review #1: Glycolysis …come sugar for the breakdown !!! B-)

In my opinion this video is superb! Whilst being quite entertaining and funny, the content of the video was very much in-depth and informative. The ‘catchiness’ of the song for lack of a better word made it so easy to pay attention to what was being taught. The diagrams were very clear, easy to follow and informative also. The length of the video was perfect in that it was not too long ( to cause the song to become annoying) and it was as short as it possibly could have been to provide the adequate information given.
In appreciation of the creativity of the video, one can see that a lot of work went into creating the song, effects and editing. As it is usually said, that music can remain into ones brain for years without the individual forgetting, just as with  the alphabet song which enables most of us to remember it, similarly the approach of a song may help with remembering the content being studied. With respect to the information presented in the video, it can be used at university level for a year one biochemistry course, as it does cover the major areas of glycolysis. However, although the ten enzymes that are present in this reaction were shown on the diagram, it would have been even more informative and helpful if he had included them into the lyrics. Also, he mentioned that Glycolysis takes place in the cytoplasm and based on my knowledge gained in class, the accurate  location is the cytosol as this is the exact area in which it takes place due to organelles not being necessary for the reactions. Overall the video was great, creative, entertaining and informative! 😀

Little one gettin' down to it dancing on the kitchen table

References:

“Glycolysis! – YouTube.” YouTube. http://www.youtube.com/watch?NR=1&v=EfGlznwfu9U&feature=fvwp (accessed April 11, 2013).

Apr 11 2013

PUBLISHED PAPER REVIEW #2: First red blood cells grown in the lab

Link to article:

http://www.newscientist.com/article/dn14565-first-red-blood-cells-grown-in-the-lab.html

Red blood cells are flattened, biconcave disc that are produced in the bone marrow. They do not have any nuclei of mitochondria but are used in the transportation of haemoglobin and therefore oxygen around the body.

Robert Lanza proud of the new discovery, exclaimed that he could create as many cells as needed, by which there would never be a shortage again.

In this experiment the cells were grown from human embryonic stem cells (ESC), which are therefore embryos than developed from in vitro fertilized eggs, cells which are able to self regenerate itself and also be differentiated into other cells.

 It was proposed that this breakthrough will be a highlight especially with respect to those born with O- negative group due to donors with this blood type being so rare. In order to produce these cells, Dr Lanza and his team of colleagues at the Mayo Clinic had to carry out an experiment where the cells were exposed to nutrients and factors of growth which firstly caused them to become haemangioblasts (precursor to blood cells) and victoriously then to red blood cells.

Though bombarded with negativity from the experts with respect to whether or not the nuclei would have been released as though in its normal environment of the body, the nuclei of these cells was in fact expelled.  

The cells were able to operate and deliver oxygen just as efficiently as a donor, although sadly O-negative red blood cells are still a mystery due to blood type determination being based on genes in the ESC. Lanza however, said that there is a possibility to produce this blood type using the skin cells of donors that are O-negative.

This great discovery and experiment makes the process of receiving blood so much safer and easier as these red blood cells do not present a risk of spreading diseases and pathogens for example HIV and hepatitis, making the process very safe and reliable.

This article was quite interesting and encouraging to know that many developments are still taking place in science in order to create betterment to all. The article could have been a bit more in depth as to how exactly the procedure was carried out but never the less a fairly good cover of the important facts of the research done. A very interesting read, it demonstrates the power of knowledge and science in assisting in social and health problems. 

References:

Apr 9 2013

Published paper review #1 :HUMAN DEMENTIA : Stress boosts Alzheimer’s proteins in the brain

link to article: 

http://www.newscientist.com/article/dn10305-stress-boosts-alzheimers-proteins-in-the-brain.html

What is this Alzeimer’s disease?

Named after Dr. Alois Alzheimer, due to an unusual sight of tangles and plaques in the brain tissue of a woman  after she died in 1906. Alzheimer’s disease, it is the disease in which is associated with dementia.

3 brains showing shrinkage and spread of disease, from mild to severe

The very visual seems torturing doesn’t it?

Dementia is a general term that describes a group of symptoms-such as loss of memory, judgment, language, complex motor skills, and other intellectual function caused by the permanent damage or death of the brain’s nerve cells, or neurons.  The alarming factor separate from the disease itself is the fact that perhaps stress and anxiety is a contributor. The hopeless thing is that stress is something that each living organism experiences in life and it is simply inevitable.

The root of this Alzheimer’s disease begins with one protein molecule, amyloid beta peptide. Research proved that dementia was at increased risk with higher levels of amyloid beta peptide. It leads to the formation of amyloid protein tangles and plaques which are the main highlight in the Alzheimer’s disease. David Holtzman and his team, carried out an experiment where a mouse was housed in a restricted cage, a third of what is the standard area. Separately, another mouse was included in the experiment as a control housed in an appropriate cage.

The experiment was scheduled for a duration of three months but to the dismay of those experimenting, only three days after the amyloid beta peptide present  in the brain fluid of the mouse being investigated in the confined cage was  strikingly 42% more than the controlled mouse. Holtzman then stated that a certain brain cell may activate the release of amyloid beta peptide due to stress.

Doctors have linked tragic events that are stressful such as losing a spouse to risks of the Alzheimer’s disease.  When a previous study was also done comparing those that suffer from anxiety and have so many depressive and negative emotions, to those that were more relaxed and laid- back with respect to life, those that were stressed were twice as much at risk to Alzheimer’s.

Amyloid beta peptides are glycoproteins that are formed from long (35 to 42 amino acids in length), insoluble fibers that are formed in a random beta sheet coil, extracellularly deposited in tissues. Generated by Amyloid Precursor Protein(APP) by beta secretease and Y- secretase, the hyrophilic N-terminal domain (residues 1 to 28) and the hydrophobic C-terminal (residues 29 to 40) are amphiphilic peptides and this heterogeneity is suspected as the reason for the toxic affect of the beta amyloid peptides.

Holtzman further explained that this mouse experiment is an addition to the growing evidence that reducing stress in daily life will also reduce the risks of Alzeimer’s disease and has great speculation of anti-anxiety drugs as a solution.

Microscopic Illustration of Alzheimer's tissue with plaques and tangles

By just one look at the brain you can see the horrendous effects of this disease. The protein fragments of abnormal clusters, built up between the nerve cells, known as plaques and twisted strands from protein with dead nerve cells tangled together.

I must admit that this article was quite interesting to read and the relating research also. I was never aware of how this disease was caused but it amazes me of how a protein can do such harm.Though the experiment done by Holtzman is not quit concrete in the science world yet, the general hypothesis is very commendable and hopefully in the not so distant future solutions could be made.

References:
Apr 2 2013

Glycolysis!! Fates of Pyruvate: Lactate

Heyy!!! 

Im, looking at this Glycolysis Process and I’m saying to my self, “How I gonna learn dis ting!!!!!!!( the glycolic pathway to make pyruvate)” This topic was very interesting, especially in tutorials. It was very interactive and this was one of those weeks where I personally wasn’t nervous….you can’t get me wrong, our team depends on: Mission to keep our marks!!  , but everyone seemed much more relaxed, I guess it’s because Sir taught more in the tutorial, which was great! I rel learn things 
 

But anywayyyy…. let’s chat a little about the glycolytic pathway for now, Just to make sure we all understand whats “supposed” to happen  and then it’s straight to the topic that’s gonna be discussed 😀

This process is universal and takes part in everyyyy cell of life –bacteria, yeast, humans, plants and animals.

It is believed to be the most ancient of metabolic pathways, having appearing prior to oxygen in abundance of the atmosphere.

Things to Note: For every glucose molecule entering glycolysis

  • 2 ATP and 2 NADH+ are used

  • 4 ATP and 2 NADH are generated

  • Net gain = 2ATP and 2 NADH

PYRUVATE  TO LACTATE

Firstly, to determine the fate of pyruvate one must ask oneself

  1. Is oxygen present?
  2. Does the cell have mitochondria?
  3. What type of organism is it?

Secondly, this is a FERMENTATION reaction.

Lets GO!

In any cell there is a limited amount of NAD+, therefore, if all goes to NADH then glycolysis will stop and  YOU WILL DIE!!. So the cell makes lactate to regenerate NAD+ so that glycolysis can continue. Step 6 of the glycolytic pathway where Gyceraldehyde-3-phosphate is converted to 1,3-Biphosphoglycerate, is whereNAD+ is needed.

This reaction is seen among humans,

Lactate is produced in muscle cells during vigorous exercise and occurs in erythrocytes because there are no mitochondria present. Lactate is acidic and the body cannot allow this to build up because it affects pH and therefore affects enzymes. Hence, why your muscles pains sooo much when you’re doing vigorous exercise after a long period of time without a break to ” catch ur breath’

IT BURNS!!!

Keep good until we chat again!! LAter 🙂

Mar 30 2013

Multiple Choice Questions!!! YOU CAN DO IT !

Put your answer in the comment section below 🙂 

SECTION I : Multiple answer MCQ
Select the correct multiple answer using ONE of the keys A, B, C, D or E as follows:

A) 3 and 4 are correct

B) 1 , 2 and 4 are correct

C) 1, 3 and 4 are correct

D) 4 only is correct

E) all are correct

1)Which of the following is NOT present in animal cells?

1) cell wall

2) plasmodesma

3) lysosome

4) chloroplast

2) Which amino acids have OH in their R groups?

1) glutamine

2) glycine

3)serine

4) threonine

Single answer MCQ

3) What is the net gain in fermentation?

A) 2 ATP and 2NADH

B) 4 ATP and 2 NADH

C) 2 ATP

D) no net gain

E) 2 NADH

 

4) What is the name of the group highlighted below:

A) keto group

B) carboxyl acid

C) aldehyde group

D) aldo-keto group

E) alcohol group

5) Denaturation is a ________ process?

A) reduction

B) destructive

C) anabolic

D) coorperative

E) oxidation

Mar 21 2013

Feverrrrr……. killin the enzymes (-_-)

Heyy!! so far the semester is going at fast paste….just hope I can keep up!

So , in one of the lectures sir just said…”ever wondered why people die from fevers ? ” We were doing enzymes and although we’ve learnt that enzymes are denatured by high temperatures, I’ve never quite related it to fevers and the human anatomy.

WHAT ARE ENZYMES?

Enzymes are biological catalyst that speed up chemical reactions in cells by lowering the activation energy through providing an alternative pathway. 

Okay, so let’s get right into the ‘heat’ of things ….

As temperature increases the rate of the reaction also increase due to the collision frequency between the reacting molecules. This therefore is increasing the collision frequency between active site and substrate. The rate of reaction don’t keep increases infinitely, however, but enzyme reaches its optimum temperature and then it begins to denature through a cooperative process.

At denaturation the active site is losing it’s 3D shape. This is due to unfolding taking place at the active site  because as the temperature is increasing the bonds holding the 3D shape is vibrating and after  the enzyme reaches it’s optimum temperature the vibrations(kinetic energy) are soooo strong that the bonds are broken and the active site loses it’s shape and can no long  react with substrates. The process is said to be coorporative because the enzymes are quickly unfolded.

The optimum temperature in humans is approximately 37 degrees Celsius, therefore when a person is ill and they  get a fever of very high temperatures for too long the conditions are severe and fatal. This is because the individual’s enzymes are being denatured and and when these enzymes loses its structure and are unable to catalyze reactions in the body. The individual is at risk to death because the reactions within the body will be too slow to sustain the body’s and life’s demands.

Hence why for example when one goes to the doctor with a fever with high temperatures they give you an ice-bath.

Personally, I have experienced this when I was younger. Can’t remember too much of the incident, but I can vividly remember that I was very ill “roasting’ with fever as we trinis say and being placed in a bathtub with FREEZZZZING water.

I got better so that’s a plus… this ice -bath is used to lower the temperature and prevent enzymes from denaturing .

Just a little something from the enzymes topic, hope you all enjoyed.

TTYL !

Reference:

BioChemJM YouTube channel

http://www.youtube.com/watch?v=qcA57r2gBL8&noredirect=1

http://www.youtube.com/watch?v=FPKAJlgMCbE