Chap Goh Mei in South East Asia

Chinese kids love New Year celebrations. It is a celebration full of festive cheers, good food, and not forgetting, the many ang paus (red packets that married folks give to the unmarried ones) that come our way. It was even more wonderful that Chinese New Year last a whole good fifteen days. Usually, the celebrations would have died down considerably by the tenth day for my family; however, that is not the end to a wonderful start of a new year.

On the fifteenth day of Chinese New Year, technically the final day of the festival, is a day known as Chap Goh Mei. In the Hokkien dialect, Chap Goh Mei simply means "the 15th night of Chinese New Year". Aside from being tagged as the last day, Chap Goh Mei is also known as the Chinese Valentine's Day. On a celebratory point of view, this night sees the gathering of family members as they sit down to a meal together. Offerings and prayers are also held on a grand scale on this particular night.

Just like Chinese New Year, Chap Goh Mei is celebrated with lots of fireworks and firecrackers. This much is true for countries that allow the use of these celebratory items. You will also see many homes gaily decorated with red lanterns and bright lights to mark the end of an auspicious occasion. In temples, thanksgivings are held while many people would be asking for the God of Prosperity to endow them with success and wealth for the coming year.

In some parts of town, you will also be able to witness cultural performances, lantern displays, lion dances and the famous Chingay (flag-balancing) procession. On a legendary point of view, Chap Goh Mei being regarded as the Chinese Valentine's Day, also brings forth lots of fun and gaiety. It is well-known that Chap Goh Mei is a night of courtship and has since been the forerunner in promoting match-making. On this night, many young ladies would make their way to the temples, dressed in their best, with hope of finding prospective suitors.

One of the fun activities that take place on this auspicious night includes the throwing of oranges into the sea by these young maidens. It is without a doubt, the most popular and colorful moment in the history of Chap Goh Mei. It is believed that by throwing tangerines into the sea, these young girls would find themselves a good husband. For many, the act of throwing tangerines into the sea also signifies that these women are available for marriage. It is also said that if someone else who sees the floating tangerine in the water and picked it up, that generally means that the single who threw it would be able to find a good spouse.

Funnily, while many of us may have imagined that such a tradition is passed forth from China, it is strangely not. In fact, this interesting practice originated from a little Malaysian island known as Penang. This took place some time towards the end of the 19th century. On a yearly basis, a large crowd would flock to the Esplanade thus jamming up the roads badly. On top of that, tangerines are sold at an exorbitantly high price but then again, who says romance is cheap?

Another story of the Chinese Valentine's Day also states that this is the only day in the whole year that young maidens are allowed to stroll the streets. However, they must be accompanied by a chaperon. Knowing this fact, many young men would gather around with hope of catching glimpses of these lovely maidens. According to the legend, there will be a matchmaker from the moon who would tie red strings of destiny on their legs. As a result, the couple will end up being together.

Although "young maidens" flock the streets freely these days thus the matchmaker from moon is not exactly needed anymore, yet the tradition of throwing tangerines into the sea still prevails. While many no longer believe in the legend, yet it is still a fun thing to do or observe. Sadly, not many people in the big cities are practicing this custom anymore. However, the tradition prevails nonetheless.

Chap Goh Mei? 

'Ten Five Night'? 

DURING ancient times, young women were forbidden to go out except on Chap Goh Mei, according to folklore.

The 15th night of the Chinese New Year celebrations is still regarded as the Chinese Valentine's Day - with some romantics tossing tangerines into the sea to find their true love.

The last and 15th day of Chinese New Year is known as Chap Goh Mei.

What does Chap Goh Mei mean?

Every February, the Chinese observe the Lantern Festival, or Chap Goh Mei - the Hokkien dialect term for the 15th night of the New Year.

This day marks the end of the Chinese New Year when lanterns are lit and hung, and people watch dragon dances in the street.

In 2021 it is being celebrated today, Friday February 26.

The day is also known as Yuan Xiao Jie, and is an important festival signifying the end of the Chinese New Year celebrations.

New year decorations are normally taken down on this day, and replaced with red lanterns to celebrate the first full moon of the year.

Apart from being a big event in China, it is also marked in other Asian countries, including Malaysia and Singapore.

Also  a day of showing artwork celebrating "the annual Taiwanese celebration, known as the Lantern Festival, one of the nation’s most treasured occasions that falls on the first full moon of the Lunar New Year.

The Lantern Festival celebrations include thousands of glowing paper lanterns.

Where did Chap Goh Mei come from?

 There are many legends and stories about the traditions and celebrations of Chap Goh Mei.

 In Malaysia, Chinese explains that legend has it that a "beautiful crane flew down to earth from heaven only to be slaughtered by some villagers.

"The crane was the Jade Emperor’s favourite crane, and he was angered by its death. He vowed vengeance against the villagers.

"On the 15th lunar day, the Jade Emperor planned to send a storm of fire down. But his daughter, Zhi Nu, took pity on the villagers.

"She warned the villagers about their impending doom, and they were troubled as they could not see a way out.

"Then, a wise man from another village came up with the suggestion for every family to hang red lanterns around their houses, set up bonfires on the streets and set off firecrackers on the 14th, 15th and 16th lunar days.

"On the 15th day, the troops descended from heaven with orders to incinerate the village, but saw that it was already “ablaze” and returned to report to the Jade Emperor.

"Since then, people celebrated the anniversary of the 15th lunar day every year by carrying lanterns on the street and setting off firecrackers."

CHINESE VALENTINE'S DAY

Chap Goh Mei is also known as the Chinese Valentine’s Day.

According to folklore, young men in ancient times could only see young women on Chap Goh Mei (also known as Chap Goh Mey).

On this particular night unmarried women - who were forbidden to go out on every other day of the year - would throw tangerines in the river or sea to enable them to marry good husbands.

It is  reported in Malaysia how this tradition persists to this day, with thousands tossing tangerines into water, hoping the fruits would be picked up by a potential romantic partner.

It's still observed among Malaysians of Chinese descent in this majority Muslim nation, and takes place on the final night of the 15-day Lunar New Year celebration.

Every February, the Chinese observe the Lantern Festival, or Chap Goh Mei - the Hokkien term for the 15th night of the New Year.

This day marks the end of the Chinese New Year when lanterns are lit and hung, and people watch dragon dances in the street.

In 2021 it is being celebrated today, Friday, February 26.

The day is also known as Yuan Xiao Jie, and is an important festival signifying the end of the Chinese New Year celebrations.

New year decorations are normally taken down on this day, and replaced with red lanterns to celebrate the first full moon of the Chinese New Year.

Where did Chap Goh Mei come from?

 There are many legends and stories about the traditions and celebrations of Chap Goh Mei.

  Malaysians explain that legend has it that a "beautiful crane flew down to earth from heaven only to be slaughtered by some villagers.

"The crane was the Jade Emperor’s favourite crane, and he was angered by its death. He vowed vengeance against the villagers.

"On the 15th lunar day, the Jade Emperor planned to send a storm of fire down. But his daughter, Zhi Nu, took pity on the villagers.

"She warned the villagers about their impending doom, and they were troubled as they could not see a way out.

"Then, a wise man from another village came up with the suggestion for every family to hang red lanterns around their houses, set up bonfires on the streets and set off firecrackers on the 14th, 15th and 16th lunar days.

"On the 15th day, the troops descended from heaven with orders to incinerate the village, but saw that it was already “ablaze” and returned to report to the Jade Emperor.

"Since then, people celebrated the anniversary of the 15th lunar day every year by carrying lanterns on the street and setting off firecrackers."

There'll be loads of sparks and fire crackers on this day .

CHINESE VALENTINE'S DAY

Chap Goh Mei is also known as the Chinese Valentine’s Day.

Tourism Malaysia explains that according to folklore, young men in ancient times could only see young women on Chap Goh Mei (also known as Chap Goh Mey).

On this particular night unmarried women - who were forbidden to go out on every other day of the year - would throw tangerines in the river or sea to enable them to marry good husbands.

Reuters reported in Malaysia how this tradition persists to this day, with thousands tossing tangerines into water, hoping the fruits would be picked up by a potential romantic partner.

It's still observed among Malaysians of Chinese descent in this majority Muslim nation, and takes place on the final night of the 15-day Lunar New Year celebration.

On Chinese Valentine's Day in Malaysia, women write their names, telephone numbers and emails on the skins of the tangerines.

If a man is interested in a woman, he hands over a banana with his details on it.

The Lunar New Year ushered in the Year of the Ox in 2021. 

Why is Chap Goh Mei celebrated?

 Chap Goh Mei is a popular festival date, marking the end of the Chinese New Year celebrations.

Apart from being synonymous with Chinese Valentine's Day, it is also a day when big family gatherings are held, to tuck into plenty of good food.

"Chap Goh Mei is also often regarded as the last day that families can toss yee sang (Cantonese-style raw fish salad) together, with the auspicious act believed to bring booming prosperity in the coming year,

Healthcare or Nightmare?

 Published on 18 Apr 2019

$1,018,469.29

Healthcare or Nightmare?

10 doctors, 58 days in the ICU, 1 gigantic bill, Mum's life lost.

Never in my life would I have ever imagined I'd see a S$1 million medical bill.

$350,000 in medications… Over a thousand doses of drugs.. Complications one after another..

One thing for sure is this... If I had known that 18 May would be the last day of her life, I would rather spend $350,000 on bringing mum the greatest joyful, loving, happiest and most comforting experiences, rather than have her go through 58 extremely painful suffering days immobile in a cold and sterile hospital room.

Looking back, it is all a lack of the right knowledge that cost my mum's life. The painful unknown is... I will never know whether we did the right thing to send mum in through these doors.

There are many health alternatives that can help reverse cancer. However, what is the DOSE and FREQUENCY required to achieve that outcome? Unfortunately it is mostly trial and error, and in mum’s instance, she was unable to consume the dose required to reverse her condition.

Because of this, we were selectively close-minded to recommendations. There were many doctors, alternatives and nutritional supplements that family & friends recommended. We explored some and missed many. However, if we stayed 100% open and explored ALL alternatives, one of them may have been able to save mum. A very costly regret…

We didn't realise how urgent cancer was. For someone with a generally healthy diet with natural foods and active lifestyle, if cancer strikes, find out if “targeted chemotherapy” is available. We learnt that chemotherapy is very helpful and effective for certain types of cancers. For aggressive treatment as chemo, it needs to be administered as soon as possible while the body still has health reserves and is able to bounce back.

We also made the mistake of thinking “all hospitals are the same". We experienced a huge difference in SPEED and EXPERTISE between public healthcare and private specialists. For a woman over 50's and post-menopause, if there is unusual swelling in the abdomen, a detailed scan to check for tumour is required immediately. When mum was first admitted in January, the doctors took 2 long weeks to discover the tumour. Something that the right scan would instantly reveal. I still believe our public healthcare is one of the best in the world, however there are simply too many patients needing the attention of overworked doctors...

Unfortunately, I feel that the healthcare ecosystem is such that specialists and private facilities are gravely expensive, and it seems that billing is structured in a way to max-out insurance payout in a cold and professionally institutionalised way. My heart felt cold when I saw that on mum’s $1 million bill, she was referred to as “Customer” and not “Patient”..

It is truly regretful that we were ignorant about mum’s insurance coverage. Had we known that mum's insurance covered private specialist treatments, we could've sought private specialist expertise from Day 1. We only went to private later on. Even though these final 58 days in a private hospital led to this insane bill, we appreciated the speed of response and level of professional expertise of the team of specialists..

At the end of the day… there are a ton of what-ifs and grey areas. What is right? What is wrong? One thing for sure is this.. Nothing can be done now to reverse the situation. Nothing can turn back time. And our hearts will miss mum forever...

More than ever now, I deeply feel that “If you do not invest time, money and energy in your health, you will spend your fortune on sickness”.

Ignorance is gravely costly. The right knowledge saves lives and protects families.

I hope this post has helped someone out there.

May we live with vigour, and die without suffering.

Rest in peace my beloved mummy...

Source: Fina Leong Facebook post.

发表于18 Apr 2019

 $ 1,018,469.29

 医疗保健还是噩梦？

 10名医生，在ICU中度过58天，1张巨额账单，使妈妈丧生。

 我一生中从未想过会看到100万新元的医疗费用。

 $ 350,000的药物…超过一千剂的药物..接连出现的并发症..

 可以肯定的是……如果我知道5月18日将是她一生的最后一天，我宁愿花350,000美元给妈妈带来最大的快乐，爱心，最幸福和最安慰的经历，而不是让她去 经历了58个极为痛苦的痛苦日子，他们无法在寒冷，无菌的病房里动弹不得。

 回顾过去，所有的正确知识的缺乏都使我的母亲丧命。 痛苦的未知数是……我永远不会知道我们是否做了正确的事情来通过这些门送妈妈进来。

 有许多健康替代品可以帮助逆转癌症。 但是，达到该结果所需的剂量和频率是什么？ 不幸的是，这主要是反复试验，而在妈妈的情况下，她无法消耗扭转病情所需的剂量。

 因此，我们选择性地紧贴建议。 家人和朋友推荐了许多医生，替代品和营养补品。 我们探索了一些而错过了许多。 但是，如果我们保持100％开放并探索所有替代方案，则其中之一可能已经节省了妈妈的费用。 非常昂贵的遗憾...

 我们没有意识到癌症是多么紧急。 对于那些以天然食品和健康生活方式为基础的健康饮食的人，如果癌症发作，请查明是否可以使用“靶向化疗”。 我们了解到化学疗法对某些类型的癌症非常有帮助和有效。 对于积极的化学疗法，需要在身体仍具有健康储备并能够反弹的同时尽快进行治疗。

 我们也误以为“所有医院都一样”。我们在公共保健和私人专家之间在SPEED和EXPERTISE方面经历了巨大的差异。对于50岁以上和绝经后的女性，如果腹部出现异常肿胀， 立即进行详细的检查以检查是否有肿瘤。一月份首次入院时，医生花了2个星期的时间才发现肿瘤。正确的检查会立即显示出来。我仍然相信我们的公共医疗保健是最好的 然而，在世界范围内，有太多患者需要过度劳累的医生的照顾...

 不幸的是，我觉得医疗保健生态系统是如此之大，以至于专家和私人机构都非常昂贵，而且看来账单的结构是通过冷漠和专业化的方式最大程度地提高保险支出的。 当我看到妈妈的100万美元账单上，她被称为“客户”而不是“患者”时，我的内心感到冷漠。

 真遗憾，我们对妈妈的保险一无所知。 如果我们知道妈妈的保险涵盖了私人专科治疗，那么我们可以从第一天开始就寻求私人专科治疗。我们后来才转到私人。 尽管这最后58天在私家医院中导致了这笔疯狂的账单，但我们还是对专家团队的响应速度和专业知识水平表示赞赏。

 一天结束时，会有大量假设分析和灰色区域。 什么是正确的？ 怎么了？ 可以肯定的是，..现在没有任何事情可以扭转这种局面。 没有什么可以倒回时间。 我们的心将永远怀念妈妈...

 我比以往任何时候都更加深刻地感到，“如果您不花时间，金钱和精力来维持健康，那么您将把大笔的钱花在疾病上”。

 无知的代价很高。 正确的知识可以挽救生命并保护家庭。

 我希望这篇文章对有人有所帮助。

 愿我们充满活力地生活，死而无苦。

 安息我亲爱的木乃伊...

 资料来源：梁菲娜（Facebook）

 https://m.facebook.com/story.php?story_fbid=10212397414864769&id=1062592446&__tn__=-R

Bunion Surgery

Bunion Surgery

A bunion, also known as hallux valgus, is bony prominence at the base of the big toe, which often results in pain, redness and rubbing in footwear. The 1st metatarsal bone abnormally angles outward towards the other foot from its joint in the midfoot. A bunion can change the shape of your foot, make it difficult for you to find shoes that fit correctly and worsen the symptoms if left untreated.

Causes

Although it is not clearly understood why bunions occur, possible causes include:

Family history and genetics

Arthritis (inflammation of the joints) including rheumatoid arthritis, psoriatic arthritis and gout

Neuromuscular conditions such as cerebral palsy which affects movement and co-ordination

Connective tissue disorders such as Marfan’s syndrome (affects the connective tissues)

Tight fitting shoes that are too tight, narrow or high heeled.

Signs and symptoms

The main indication of a bunion is the pointing of the big toe towards the other toes of the foot. Other signs and symptoms include:

Pain and swelling over the big toe that increases while wearing shoes

Swelling with red, sore and calloused skin at the base of the big toe

Inward turning of the big toe pushes the second toe out of place

Bony bump at the base of the big toe

Sore skin over the bony bump

Difficulty walking and wearing shoes

Diagnosis

The diagnosis of a bunion by an surgeon includes taking a medical history, and performing a physical examination to assess the extent of misalignment and damage to the soft tissues. Your surgeon will usually order weight bearing X-rays that are. taken while standing to access the severity of the bunion and deformity of the toe joints.

Treatment

Your Physician may have already initially recommended conservative treatment measures with the goal of reducing or eliminating your foot pain.

Such measures can include:

Medications for relieving pain and inflammation

Wearing surgical shoes with a wide and high toe box, avoiding tight, pointed or high-heeled shoes.

Use of orthotics to realign the bones of your foot and ease pain.

Padding of bunions

Ice applications several times a day

Conservative treatment measures can help relieve the discomfort of a bunion, however these measures will not prevent the bunion from becoming worse.

Surgery

Watch video. 《 click here 》 

Surgery is the only means of correcting a bunion. Surgery is also recommended when conservative measures fail to treat the symptoms of a bunion.

There are many surgical options to treat a bunion. The common goal is to realign the bones in the foot, correct the deformity, and relieve pain and discomfort. The surgery is performed as a day procedure, under the effect of a light general anaesthetic and a regional nerve block. When you wake up, you will not be in pain and will be able to walk on your foot straight away.

Osteotomy is a common type of bunion surgery that involves the surgical cutting and realignment of the bones around your big toe. Your surgeon selects the appropriate surgical procedure based on the type of bunion and its severity.

There are 3 main types of osteotomies used by foot and ankle surgeons; namely akin osteotomy, chevron osteotomy, and scarf osteotomy.

Akin Osteotomy

Akin osteotomy corrects the sideways deviation of the big toe. In this procedure, your surgeon makes a small cut in the proximal phalanx (base of the big toe) and removes a wedge of bone to straighten the big toe. The bony fragments are then stabilised using a screw or staples. This procedure is often used in conjunction with the other procedures below.

Chevron osteotomy

A chevron osteotomy is usually recommended for mild to moderate bunion deformities. During this procedure, your surgeon will make an incision over your big toe. The joint capsule is opened and the bunion is removed using a surgical saw. A V-shaped cut is made on your big toe and the metatarsal bones are shifted to bring your toe into its normal anatomical position. The bunion is then shaved and the soft tissues are realigned to correct the position. Akin osteotomy may be performed if necessary. The mobility of your big toe is examined, and the capsule and wound are re-approximated with sutures. Screws or pins are used to hold the bones in their new position until healing.

This procedure can also be performed minimally invasively with keyhole style incisions.

Arthrodesis: Involves fusing the two bones that form the big toe joint. This procedure is used for severe bunions and when arthritis has set in. The movement of your big toe is reduced following this procedure but pain and deformity are very well controlled.

Scarf Osteotomy

Scarf osteotomy is usually recommended for moderate to severe bunion deformities.

Your surgeon will make an incision along your big toe and open up the joint capsule to expose the bump. The bump on your big toe is then removed using a bone saw. Your first metatarsal bone is then cut in a Z shape and realigned to correct the deformity. Your surgeon will fix the cut bone with pins or screws. The joint capsule and surgical wounds are then re-approximated using dissolvable sutures keeping your toe in a straight position. This is a very powerful corrective procedure with excellent long term results.

Risks and complications

As with any surgery, bunion surgery involves certain risks and complications. They include:

infection

recurrence of the bunion

nerve damage

unresolved pain and swelling

Joint stiffness or restricted movement

Delayed healing or healing in the wrong position

In rare cases, a second surgery may be necessary to correct the problems.

Post-operative care

Patients should follow all instructions given by the surgeon following the surgery. These include:

Keep your dressings dry and leave them in place until your next outpatient appointment.

Minimise walking where possible.

Elevate the foot to minimise swelling as much as possible for the first 6 weeks.

You will have to wear specially designed post-operative shoes to protect the wounds and assist in walking

You may not be able to wear regular shoes for 6 weeks

A bunion is bony prominence caused by mal-alignment of the bones in the foot. Bunions result in pain, swelling and deformity of the foot and make it difficult to find comfortable shoes. Bunion surgery can be performed to realign the joint, correct the deformity, and relieve the pain and discomfort.

Diffusion Time

 Diffusion Time 

Diffusion 

Time Calculator 

When considering the diffusion of ions and molecules in solutions, it is generally useful to be able to estimate the time required for diffusion over a given distance. From a physiological perspective, this knowledge helps us better understand how long it takes molecules and ions to travel physiologically relevant distances by diffusion alone. For example, it is of value to know how long it takes molecular O₂ to reach metabolically active cells 10 μm away from a capillary. As another example, it is important to know how long it takes a neurotransmitter molecule released from the pre-synaptic neuron to diffuse across the synaptic cleft of 20-50 nm to reach target receptors on the post-synaptic plasma membrane. Likewise, numerous other physiological examples can be considered.

While in solutions, diffusing solutes move in three dimensions down a concentration gradient from an area of higher concentration to an area of lower concentration, a simple equation may be used to approximate the time it takes a given molecule to diffuse an average distance in one dimension (see equation below). This equation is also referred to as the Einstein's approximation equation. The important determinants of diffusion time (t) are the distance of diffusion (x) and the diffusion coefficient (D). Diffusion time increases with the square of diffusion distance. The diffusion coefficient is unique for each solute and must be determined experimentally. It is a function of a number factors including molecular weight of the diffusing species, temperature, and viscosity of the medium in which diffusion occurs. For ions in aqueous solutions, the ion charge density influences the size of the hydration shell around the ion which, in turn, influences the value of the diffusion coefficient for that ion. For very large molecules (macromolecules), molecular shape also plays a role. Diffusion time is inversely proportional to the diffusion coefficient (D). Table 1 provides the diffusion coefficient for a few selected ions and molecules.

Approximation equation for diffusion time

Table 1. Diffusion coefficient values for selected ions and small and large molecules.

Ion/Molecule	Atomic/Molecular Weight (g/mol)	Diffusion Coefficient (cm2/s)
H+	1.008	9.31 × 10-5
Na+	22.990	1.33 × 10-5
K+	39.098	1.96 × 10-5
Ca2+	40.078	0.79 × 10-5
Cl-	35.453	2.03 × 10-5
Ammonia (NH3)	17.031	1.51 × 10-5
Oxygen (O2)	31.999	2.10 × 10-5
Carbon dioxide (CO2)	44.01	1.97 × 10-5
Urea	60.055	1.38 × 10-5
Glucose	180.156	5 × 10-6
Sucrose	342.296	5.23 × 10-6
Hemoglobin	68,000	6.9 × 10-7
DNA	≈ 6,000,000	1.3 × 10-8

Note: The diffusion coefficient varies with temperature and is also a function of the medium in which diffusion occurs. The values shown are for diffusion in water (H₂O) at 25 °C.

D is the diffusion coefficient of a solute in free solution. The diffusion coefficient determines the time it takes a solute to diffuse a given distance in a medium. D has the units of area/time (typically cm2/s). Its value is unique for each solute and must be determined empirically. D is a function of both the physical characteristics of the solute and those of the medium. It is inversely related to the molecular weight of the solute. For ions, the size of the hydration shell influences the value of D. For large molecules, molecular shape also plays a role in determining the value of D. Temperature also influences D. A few selected examples are shown in Table 1.

x is the mean distance traveled by the diffusing solute in one direction along one axis after elapsed time t.

t is the elapsed time since diffusion began. Diffusion time increases with the square of diffusion distance. Diffusion time is inversely proportional to the diffusion coefficient (D).

Table 1. Diffusion coefficient values for selected ions and small and large molecules.

Ion/Molecule , Atomic/Molecular Weight

(g/mol), Diffusion Coefficient

(cm2/s).

H+ ,1.008, 9.31 × 10-5.

Na+ ,22.990, 1.33 × 10-5.

K+, 39.098, 1.96 × 10-5.

Ca2+, 40.078, 0.79 × 10-5.

Cl-, 35.453, 2.03 × 10-5.

Ammonia (NH3), 17.031, 1.51 × 10-5.

Oxygen (O2), 31.999, 2.10 × 10-5.

Carbon dioxide (CO2), 44.01, 1.97 × 10-5.

Urea, 60.055, 1.38 × 10-5.

Glucose, 180.156, 5 × 10-6.

Sucrose, 342.296, 5.23 × 10-6.

Hemoglobin, 68,000, 6.9 × 10-7.

DNA ≈, 6,000,000, 1.3 × 10-8.

Note: The diffusion coefficient varies with temperature and is also a function of the medium in which diffusion occurs. The values shown are for diffusion in water (H2O) at 25 °C.

Diffusion time calculator

《Click here 》 

Interpretation and physiological significance

The above calculator allows us to evaluate the effectiveness of diffusion over physiologically relevant distances. The diffusion time values shown in Table 2 were obtained by considering the diffusion of O2 over a range of distances. Looking at these values, it can be concluded that while diffusion is adequate for the movement of ions/molecules over short distances, diffusion times are unrealistically long for movement over long distances. Thus, for large multicellular organisms, diffusion alone is grossly inadequate for ensuring the delivery of nutrients to metabolically active cells deep within the tissues. It is for this reason that in large organisms such as humans, a cardiovascular system is present to transport nutrients to all cells of the body. This system is composed of blood vessels and the heart. The heart functions as a pump to move blood in the blood vessels. The blood vessels serve as a conduit for the transport of molecules to the tissues, however, exchange of materials between the circulatory system and tissues takes place only across the capillary endothelium. In mammals, the circulatory system is such that no cell is more than approximately 10 μm from a capillary. This ensures proper nourishment and waste removal for all cells of the body. This system is also responsible for collection of waste and transport to organs involved in waste elimination (lungs and kidneys).

As another example, we can consider the diffusion of acetylcholine across the neuromuscular junction where the synaptic cleft is approximately 50 nm. Using 4 × 10-6 cm2/s for the diffusion coefficient of acetylcholine in the extracellular space of the neuromuscular junction, it can be calculated that it takes acetylcholine approximately 3.1 μs to diffuse from its pre-synaptic release site to reach the post-synaptic nicotinic acetylcholine receptors. This diffusion time is only a minor fraction of the total synaptic delay of approximately 500 μs observed at the neuromuscular junction.

Table 2. Time required for diffusion of O2 over a range of distances.

 

Distance of Diffusion, Approximate Time Required.

10 nm, 23.8 ns.

50 nm, 595 ns.

100 nm, 2.38 μs.

1 μm, 238 μs.

10 μm, 23.8 ms.

100 μm, 2.38 s.

1 mm, 3.97 min.

1 cm, 6.61 hours.

10 cm, 27.56 days.

References

1. Atkins, P.W. (1994) Physical Chemistry. 5^th Edition. W. H. Freeman, New York.
2. Hille, B. (2001) Ion Channels of Excitable Membranes. 3^rd Edition. Sinauer Associates, Inc., Sunderland.
3. Robinson, R.A., Stokes, R.H. (1968) Electrolyte Solutions. Revised 2^nd Edition. Butterworths, London.
4. Sperelakis, N., Editor. (2001) Cell Physiology Sourcebook: A Molecular Approach. 3^rd Edition. Academic Press, San Diego.
5. Van Winkle, L.J. (1999) Biomembrane Transport. Academic Press, San Diego.
6. Weiss, T.F. (1996) Cellular Biophysics: Transport (Vol. 1). MIT Press, Cambridge.

The flow of water in and out of the cell is occurring

 First, we must have energy. More specifically, have the source of energy, which is water.

Then we can build up the vitality. 

The flow of water in and out of the cell is occurring at equal rates. 

RBC will swell and undergo hemolysis (burst). RBC will lose water and undergo crenation (shrivel).

Give specific examples of where the following methods of Active Transport would be used in your body:

1.Protein Pumps Sodium- potassium pump - Exchanges sodium ions for potassium ions across the plasmamembrane of animal cells.

2.Phagocytosis = In the tissues, the monocytes are transformed into phagocytic cells called macrophages. The macrophages move through the tissues of the body performing phagocytosis and destroying parasites. 

3.Exocytosis = When glucose concentration in the bloodis too high, insulin is released from islet beta cells causing cells and tissuesto take up glucose from the blood. When glucose concentrations are low, glucagon is secreted from islet alpha cells. 

This causes the liver to convert stored glycogen to glucose. Glucose is then released into the blood causing blood-glucose levels to rise. 

In addition to hormones, the pancreas also secretes digestive enzymes (proteases, lipases, amylases) by exocytosis. 

Give a brief description on each of the cell types below.

Squamous- Thin

Squamous

Cuboidal

Columnar

When red blood cells are in a hypertonic (higher concentration) solution, water flows out of the cell faster than it comes in. This results in crenation (shriveling) of the blood cell. On the other extreme, a red blood cell that is hypotonic (lower concentration outside the cell) will result in more water flowing into the cell than out.

Osmosis and Diffusion

Fish cells, like all cells, have semipermeable membranes. Eventually, the concentration of "stuff" on either side of them will even out. A fish that lives in salt water will have somewhat salty water inside itself. Put it in freshwater, and the freshwater will, through osmosis, enter the fish, causing its cells to swell, and the fish will die. What will happen to a freshwater fish in the ocean?

Osmosis

Imagine you have a cup that has 100mL water, and you add 15g of table sugar to the water. The sugar dissolves and the mixture that is now in the cup is made up of a solute (the sugar) that is dissolved in the solvent (the water). The mixture of a solute in a solvent is called a solution.

Imagine now that you have a second cup with 100mL of water, and you add 45g of table sugar to the water. Just like the first cup, the sugar is the solute, and the water is the solvent. But now you have two mixtures of different solute concentrations. In comparing two solutions of unequal solute concentration, the solution with the higher solute concentration is hypertonic, and the solution with the lower solute concentration is hypotonic. Solutions of equal solute concentration are isotonic. The first sugar solution is hypotonic to the second solution. The second sugar solution is hypertonic to the first.

You now add the two solutions to a beaker that has been divided by a semipermeable membrane, with pores that are too small for the sugar molecules to pass through, but are big enough for the water molecules to pass through. The hypertonic solution is one one side of the membrane and the hypotonic solution on the other. The hypertonic solution has a lower water concentration than the hypotonic solution, so a concentration gradient of water now exists across the membrane. Water molecules will move from the side of higher water concentration to the side of lower concentration until both solutions are isotonic. At this point, equilibrium is reached.

Red blood cells behave the same way (see figure below). When red blood cells are in a hypertonic (higher concentration) solution, water flows out of the cell faster than it comes in. This results in crenation (shriveling) of the blood cell. On the other extreme, a red blood cell that is hypotonic (lower concentration outside the cell) will result in more water flowing into the cell than out. This results in swelling of the cell and potential hemolysis (bursting) of the cell. In an isotonic solution, the flow of water in and out of the cell is happening at the same rate.

Figure 8.4.1 : Red blood cells in hypertonic, isotonic, and hypotonic solutions.

Osmosis is the diffusion of water molecules across a semipermeable membrane from an area of lower concentration solution (i.e., higher concentration of water) to an area of higher concentration solution (i.e., lower concentration of water). Water moves into and out of cells by osmosis.

• If a cell is in a hypertonic solution, the solution has a lower water concentration than the cell cytosol, and water moves out of the cell until both solutions are isotonic.

• Cells placed in a hypotonic solution will take in water across their membranes until both the external solution and the cytosol are isotonic.

A red blood cell will swell and undergo hemolysis (burst) when placed in a hypotonic solution. When placed in a hypertonic solution, a red blood cell will lose water and undergo crenation (shrivel). Animal cells tend to do best in an isotonic environment, where the flow of water in and out of the cell is occurring at equal rates.

Diffusion

Passive transport is a way that small molecules or ions move across the cell membrane without input of energy by the cell. The three main kinds of passive transport are diffusion (or simple diffusion), osmosis, and facilitated diffusion. Simple diffusion and osmosis do not involve transport proteins. Facilitated diffusion requires the assistance of proteins.

Diffusion is the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration. For cell transport, diffusion is the movement of small molecules across the cell membrane. The difference in the concentrations of the molecules in the two areas is called the concentration gradient. The kinetic energy of the molecules results in random motion, causing diffusion. In simple diffusion, this process proceeds without the aid of a transport protein. It is the random motion of the molecules that causes them to move from an area of high concentration to an area with a lower concentration.

Diffusion will continue until the concentration gradient has been eliminated. Since diffusion moves materials from an area of higher concentration to the lower, it is described as moving solutes "down the concentration gradient". The end result is an equal concentration, or equilibrium, of molecules on both sides of the membrane. At equilibrium, movement of molecules does not stop. At equilibrium, there is equal movement of materials in both directions.

Not everything can make it into your cells. Your cells have a plasma membrane that helps to guard your cells from unwanted intruders.

The permeability con­stant for water is about 1 x 10 -4 cm/sec. This value is only 0.001% of the rate at which water molecules dif­fuse across a water layer the thickness of the cell membrane. This implies that if they are present, hydrophilic pores must cover only a small percentage of the surface area of the cell.

The Plasma Membrane and Cytosol

If the outside environment of a cell is water-based, and the inside of the cell is also mostly water, something has to make sure the cell stays intact in this environment. What would happen if a cell dissolved in water, like sugar does? Obviously, the cell could not survive in such an environment. So something must protect the cell and allow it to survive in its water-based environment. All cells have a barrier around them that separates them from the environment and from other cells. This barrier is called the plasma membrane, or cell membrane.

The Plasma Membrane

The plasma membrane (see figure below) is made of a double layer of special lipids, known as phospholipids. The phospholipid is a lipid molecule with a hydrophilic ("water-loving") head and two hydrophobic ("water-hating") tails. Because of the hydrophilic and hydrophobic nature of the phospholipid, the molecule must be arranged in a specific pattern as only certain parts of the molecule can physically be in contact with water. Remember that there is water outside the cell, and the cytoplasm inside the cell is mostly water as well. So the phospholipids are arranged in a double layer (a bilayer) to keep the cell separate from its environment. Lipids do not mix with water (recall that oil is a lipid), so the phospholipid bilayer of the cell membrane acts as a barrier, keeping water out of the cell, and keeping the cytoplasm inside the cell. The cell membrane allows the cell to stay structurally intact in its water-based environment.

The function of the plasma membrane is to control what goes in and out of the cell. Some molecules can go through the cell membrane to enter and leave the cell, but some cannot. The cell is therefore not completely permeable. "Permeable" means that anything can cross a barrier. An open door is completely permeable to anything that wants to enter or exit through the door. The plasma membrane is semipermeable, meaning that some things can enter the cell, and some things cannot.

Molecules that cannot easily pass through the bilayer include ions and small hydrophilic molecules, such as glucose, and macromolecules, including proteins and RNA. Examples of molecules that can easily diffuse across the plasma membrane include carbon dioxide and oxygen gas. These molecules diffuse freely in and out of the cell, along their concentration gradient. Though water is a polar molecule, it can also diffuse through the plasma membrane.

Figure 8.4.2 : Plasma membranes are primarily made up of phospholipids (orange). The hydrophilic ("water-loving") head and two hydrophobic ("water-hating") tails are shown. The phospholipids form a bilayer (two layers). The middle of the bilayer is an area without water. There can be water on either side of the bilayer. There are many proteins throughout the membrane.

Cytosol

The inside of all cells also contain a jelly-like substance called cytosol. Cytosol is composed of water and other molecules, including enzymes, which are proteins that speed up the cell's chemical reactions. Everything in the cell sits in the cytosol, like fruit in a Jell-o mold. The term cytoplasm refers to the cytosol and all of the organelles, the specialized compartments of the cell. The cytoplasm does not include the nucleus. As a prokaryotic cell does not have a nucleus, the DNA is in the cytoplasm.

Supplemental Resources

The Plasma Membrane: http://www.youtube.com/watch?v=moPJkCbKjBs