Happy New Year

Keep the smile,
leave the tear,
Think of joy,
forget the fear,
Hold the laugh,
leave the pain,
Be joyous,
Coz its new year!
HAPPY NEW YEAR

Factors affecting the rate of photosynthesis

Affected by : 
Light intensity
Concentration of carbon dioxide
Temperature

Light intensity 

Light is essential during light reaction of photosynthesis.

When concentration of carbon dioxide & temperature are controlled at constant levels,

the rate of photosynthesis is directly proportional to light intensity up to a certain point.

As the light intensity increases, the rate of photosynthesis increases up to a saturated point

(point P).

Beyond the saturation point (point P), further increase in light intensity does not increase

the rate of photosynthesis because of concentration of carbon dioxide & temperature

become the limiting factors.
Both the concentration of carbon dioxide & temperature stop the rate of reaction from
increasing further along PQ.
The rate of photosynthesis will not increase although the light intensity is increases.        
When CO₂ concentration is raised to 0.13%, the rate of photosynthesis is higher. (graph II)
At very high light intensity, the rate of photosynthesis slows down because the chlorophyll
pigment is damaged by UV rays.

 

CO₂ is required in dark reaction as raw material used in the synthesis of glucose.
If there is no other limiting factors that limit the photosynthesis process, as the
concentration of carbon dioxide increases, the rate of photosynthesis increases.
Although the concentration of carbon dioxide keeps increasing, the rate of photosynthesis
will not increase further because light intensity acts as limiting factor.

 

Dark reaction is catalysed by enzymes; thus changes in temperature affects the rate of 
photosynthesis.
An increase in 10⁰C in the surrounding temperature will decrease the rate of photosynthesis
The optimum temperature of varies for each species.
But most plants : between 25⁰C to 30⁰. 
If temperature is too high, photosynthetic enzymes are destroyed by denaturation.
Photosynthesis stops.

Biology Workshop F4 Collegians 2012(Answering P3 & Essay)

Digestion, Absorption, Assimilation (Simple explanation)





Human Digestion

Mouth

Salivary glands produce saliva which contains salivary amylase. Starch is hydrolysed into maltose.

Stomach

Gastric glands produce gastric juice which contains enzyme pepsin and rennin. Proteins are hydrolysed into polypeptide. Caseinogens is converted into casein.

Duodenum

Liver produces bile. Bile emulsifies lipid. Pancreas produces pancreatic amylase, trypsin & lipase. Starch is hydrolysed into maltose. Polypeptide is hydrolysed into peptide. Lipid is hydrolysed into fatty acids & glycerol.

Ileum

Intestinal gland secretes intestinal juice which contains enzyme maltase, lactase, sucrase and erepsin. Maltase hydrolyses maltose into glucose & glucose. Lactase hydrolyses lactose into glucose and galactose. Sucrase hydrolyses sucrose into glucose & fructose. Erepsin hydrolyses peptide into amino acids

Absorption

Glucose, amino acids, Vitamins B & C are absorbed through facilitated diffusion into blood capillaries in the villi then into hepatic portal vein that leads to liver.

Fatty acids, glycerols, Vitamin ADEK are absorbed into lacteals (FA & G in the form of lipid droplets). Then lacteal converge into lymphatic system. Flows into right lymphatic duct & thoracic duct, finally enters subclavian veins into bloodstream.

Assimilation

In the liver

Liver synthesises plasma proteins from amino acids. Short supply of glucose – liver converts amino acids into glucose. Excess amino acids are broken down – deamination. Urea is produced & transported to kidney to be excreted.

Glucose is converted & stored in the liver. Blood sugar level falls, glycogen is converted back into glucose. Liver full of glucose – converted into lipids.

Lipids enter the heart through subclavian vein transported in the bloodstream to body cells.

In the cells

Amino acids – used for synthesising new protoplasm & repair damaged tissues. Build enzymes & hormones. Synthesise plasma membrane.

Glucose – oxidised to release energy (cellular respiration). Used for muscle contraction, synthesis of proteins. Excess glucose is stored in muscles (glycogen).

Lipids – phospholipids & cholesterol : components of plasma membrane

Fats are stored around organs act as cushions that protect organs from injuries. Excess fats are stored in adipose tissue as reserve energy. When body lacks glucose, fats are oxidised to release energy.

Last-Minute Study

Exams are just around the corner. Being prepared reduces stress so take time to set your priorities in the days ahead. 

Keep friends and family updated about your plans and ask them to cheer you along to the finish line.
Think about what you’ve already covered and review your study schedule. 

Set 15 minute study goals and take a 10 minute break every 50 minutes or after two hours. 

Repetition improves memory. Continue being an active learner- eg. use highlighters, make summaries or mind maps. 

You might like to revise past papers, practice writing timed essays or study with a friend. Give yourself regular rewards.
If you become distracted while studying, just notice and refocus on the task at hand. Break tasks down into smaller chunks and tackle them one at a time. 

Remind yourself “I can do this” “I enjoy learning.” Expect to succeed.
Minimise interruptions eg. turn your mobile on silent. 

If you find your self procrastinating, weigh up the pros and cons. 

Stay motivated by imagining a well earned break or seeing yourself on graduation day. 

Maintain some balance. A brisk walk will clear your mind.
Try not to live on caffeine.
If you like, you can practice slow abdominal breathing whenever you sit down to study.
Inhale in a way that allows your stomach to expand. As you exhale, your stomach should move inward. If you practice this for a minute your body and mind will naturally begin to relax.
You can use this technique in your exams to improve your concentration or calm yourself.
Each day imagine yourself in the exam room, knowing how to answer the questions well.
Make sure you check the date and location of your exams.

On the day of the exam:
Eat well. Have a good breakfast the morning of your exam.
Wear a watch, check your pens etc. and give your self extra time to travel.
Sit apart from the anxious crowd just prior to your exam.
Use self talk to stay focussed. Tell yourself “I’m calm and thinking clearly.”
In the exam room, scan your entire paper, read questions carefully and allocate your time according to marks.
Some anxiety is a cue to cope. If you feel too anxious or blank out for a moment, just take a few slow, deep breaths and remind yourself “Relax. Concentrate. I can easily do this, just one step at a time.”
You can also describe your surroundings for a moment, have a drink of water.
You can take a mental break and then begin again. 

Don’t give up.
Dangle your arms by your sides to promote circulation when resting briefly from writing.
 

Good luck and enjoy.

Weird Diseases

Epidermodysplasia verruciformis
Epidermodysplasia is caused by a genetic skin defect, in which skin is filling up with various dirty looking warts.  Warts are found mainly in areas exposed to sunlight.

Calcinosis  
This is a rare disease in which calcium deposits in soft tissues. In practice the victim body is begins to flow thick white liquid like milk and various body joints leave their places.

Argyria 

This a weird disease in which skin turns blue. That disease is also called blue skin failure. This disease mostly effect on face and hands, but it can also affect the whole body.

Elephantiasis

This is the most bizarre Illness, in which lymph clogs the lymph vessels. This unusual blockage helps to increase the body part where the lymph vessel is blocked. A typical example is the elephant’s leg.

Werewolf Syndrome
It is a disease in which a victim grows at an abnormal amount of body hair in places where they usually not grow. Like on face and hands.

Pica Syndrome

It is a disease in which people tend to eat and taste things that are very bad in taste, like plastic, stones, paper, plaster, clay, rubber, soap, etc. Doctors believe that this disorder is developed in a person when the body has enough minerals, but do not know exactly how to start and or how to treat them.

Blaschko lines

This is a very strange and still unexplained syndrome, first described in 1901 by a German dermatologist Alfred Blaschko. Patients in this syndrome got visible stripes on the body in various shapes like V, and P. These lines have no connection with the nerve, muscle or lymphatic system.

Cutaneous horns

The reasons of this rare disease are unknown why some people develop these unusual horns, but the problem is linked to radiation exposure. This disease does occur in humans in areas where a lot of sunshine.

Necrotising fasciitis

This disease is also called meat eating bacteria disorder. It is caused by an infection of the lower layer of skin that usually gets there by various abrasions on the skin. This is a very dangerous disease, which leads to death.

Ehlers-Danlos Syndrome

This disease is also associated with the skin, in which the skin becomes thin and easily extensible.

My Students

I am a teacher so they say

But who is teaching who?

Students learn from teachers

Or so I thought was true

But if the truth be known, dear child

I’ve learned much more from you!

I’ve learned to say I don’t know

But how can we find out?

I’ve learned to laugh at my mistakes

And push away the doubt

I’ve learned to love each one of you

Even if you pout

You’ve reminded me of growing pains

I thought were left behind me

You’ve reminded me of days gone by

When I was young and free

You’ve reminded me of long-last dreams

Which I need to see

I’ve seen you struggle with each other

Hitting, hurting and breaking hearts

I’ve seen you roll eyes at peers

Saying unkind words and snide remarks

I’ve seen you do those human things

Adults do, but rather kids not start

You’ve taught me how diverse we are

And life’s not always fair

You’ve taught me how unique you are

And why we need to care

You taught me to be reflective

Looking inward, unafraid to stare

I am a teacher, yes I know

But I am a student too

Students learn from teachers

And the reverse, as shown, is true

So what I want to leave with you....

Learning is a circle, you so, and do and do........