Biology

MECHANISM OF INHIBITION. OR PEPSIN BY PEPSTATIN Pepstatin, a specific inhibitor of acid proteases, binds tightly to pepsin. Although the binding is not of the covalent nature, the inhibition roughly follows the stoicheometrical mode. Pepstatin can be used to titrate pepsin. Formation of an equimolar pepsin-pepstatin complex can be shown by gel filtration. Diacetylpepstatin, which has weaker activity than pepstatin com- petitively inhibits pepsin with a dissociation constant of 7.3XlO"6M. Data of pepstatin binding of chemically modified pepsins suggested that pepstatin binds with the active site surrounded by two aspartic acid moieties. Pepstatin, isovaleryl-L-valyl-L-valyl-4-amino-3-hydroxy-6-methylheptanoyl-L- alanyl-4-amino-3-hydroxy-6-methylheptanoic acid, was discovered in streptomyces culture nitrates and has been shown to be a specific inhibitor of acid proteases1*2'^. It shows a strong protective effect against pylorus-ligated rat stomach ulcer, and an effect...

                                 CANCER CELLS.          Cancer cells  are cells that divide relentlessly, forming solid tumors or flooding the blood with abnormal cells.  Cell division  is a normal process used by the body for growth and repair. A parent cell divides to form two daughter cells, and these daughter cells are used to build new tissue or to replace cells that have died because of aging or damage. Healthy cells stop dividing when there is no longer a need for more daughter cells, but cancer cells continue to produce copies. They are also able to spread from one part of the body to another in a process known as  metastasis . There are different categories of cancer cell, defined according to the cell type from which they originate. [2] Carcinoma , the majority of cancer cells are  epithelial  in origin, beginning in the membra...

Recent research has helped to solidify the link between the proper function of the vertebral arteries and vertigo. The researchers specifically focused on a rare condition called loop formation. It is a disorder where small loops form in the vertebral arteries, thereby restricting blood flow. When a cross-section of vertigo patients was studied, this condition seemed to be more common. What else can cause kinks in the vertebral arteries leading to reduced blood flow? Does understanding of the conditions that bring vertigo provide information into a natural way to find relief? Read on to learn more. What Can Reduce Vertebral Blood Flow and Lead to Vertigo? The upper cervical vertebrae play a major role in facilitating blood flow to the brain. Misalignment of the C1 and C2 vertebrae can result in reduced blood flow. Vertigo is not the only possible condition that may result from this scenario. Migraines are also common when these circumstances exist. This explains why it is s...

                                What Is Ovulation? Ovulation is the release of an egg from one of a woman's ovaries. After the egg is released, it travels down the fallopian tube, where fertilization by a sperm cell may occur.  Ovulation is the release of an egg from one of a woman's ovaries. After the egg is released, it travels down the fallopian tube, where fertilization by a sperm cell may occur.  Ovulation typically lasts one day and occurs in the middle of a woman's menstrual cycle, about two weeks before she expects to get her period. But the timing of the process varies for each woman, and it may even vary from month to month.  If a woman is hoping to become pregnant, she will want to keep track of when she may be ovulating. Knowing when a woman is ovulating each month is helpful because she is the most fertile — or able to become pregnant —around the time of ovulation....

                                     Nipple The  nipple  is a raised region of tissue on the surface of the  breast  from which, in females,  milk  leaves the breast through the  lactiferous ducts  to feed an infant. The milk can flow through the nipple passively or it can be ejected by  smooth   muscle contractions  that occur along the ductal system. The nipple is surrounded by the  areola , which is often a darker color than the surrounding skin. A nipple is often called a  teat  when referring to non-humans. Nipple or teat can also be used to describe the flexible mouthpiece of a  baby bottle . In humans, nipples of both males and females can be stimulated as part of sexual arousal. In many cultures, human female nipples are  sexualized , or "regarded as sex objects and evaluated in ...

                                 Cats Menstruation Cats are polyestrous, which means heat cycles happen periodically during their fertile years. 1 These cycles may start as early as four-months-old and will continue until a cat is either bred or spayed. Heat cycles in cats can last several days, up to two weeks, and repeat themselves every two to three weeks. Like most female mammals, cats go through physical cycles that prepare their bodies for fertilization and birth. In humans, this cycle is called "menstruation." In felines, it is called "estrus." When female cats are experiencing estrus they are said to be "in heat" and are hormonally receptive to both intercourse and reproduction. Cats can go into heat in late kittenhood, making it necessary to spay them if a pregnancy, and the responsibility of raising and finding good homes for kittens, is unwanted.  Female cats have period cyc...

                                        HORMONES    Hormones are chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. There are many types of hormones that act on different aspects of bodily functions and processes. Some of these include: Development and growth Metabolism of food items Sexual function and reproductive growth and health Cognitive function and mood Maintenance of body temperature and thirst Where are they secreted from? Hormones are secreted from the endocrine glands in the body. The glands are ductless, so hormones are secreted directly into the blood stream rather than by way of ducts. Some of the major endocrine glands in the body include: Pituitary gland Pineal gland Thymus Thyroid Adrenal glands Pancreas Testes Ovaries These organs secrete hormone in microscop...

               STRESS HORMONE AND   MANAGEMENT What Is Cortisol? Cortisol is a naturally-occurring steroid hormone that plays a key role in the body's stress response.1 While it is often called "the stress hormone" for its best-known role, it also contributes to many of the body's processes. It's secreted by the adrenal glands and involved in the regulation of the following functions and more: Signs of High Cortisol When cortisol levels stay too high, you might experience a range of unwanted symptoms. Higher and more prolonged levels of cortisol in the bloodstream (such as those associated with chronic stress) have been shown to have negative effects, such as: Blood sugar imbalances such as hyperglycemia Decreased bone density 3  Decreases in muscle tissue Higher blood pressure Impaired cognitive performance Increased abdominal fat Lowered immunity and inflammatory responses in the body, slowed wound healing, and oth...

                                Irregular Periods The normal length of a woman’s menstrual cycle is 28 days, but this varies between individuals. Irregular menstruation is when the length of the cycle is more than 35 days, or if the duration varies. A period, or menstruation, is the part of the menstrual cycle in which the endometrium, which is the lining of the uterus, is shed. This appears as bleeding from the womb that is released through the vagina. Periods usually start during puberty, between the ages of 10 and 16 years, and they continue until menopause, when a woman is 45- to 55-years old. Irregular periods, also called oligomenorrhea, can occur if there is a change in  contraception method, a hormone imbalance, hormonal changes around the time of the menopause, and endurance exercises. Treatment for irregular periods during puberty and around the menopause is not usually necessary, ...

            Why do we get hiccups (उचक्या /हिचकी) ?      Hiccups are caused by involuntary contractions of your diaphragm — the muscle that separates your chest from your abdomen and plays an important role in breathing. This involuntary contraction causes your vocal cords to close very briefly, which produces the characteristic sound of a hiccup. Hiccups can be annoying but they’re usually short-lived. However, some people may experience recurrent episodes of persistent hiccups. Persistent hiccups, also known as chronic hiccups, are defined as episodes that last longer than 48 hoursTrusted Source. At its most basic, a hiccup is a reflex. It happens when a sudden contraction of your diaphragm causes the muscles of your chest and abdomen to shake. Then, the glottis, or the part of your throat where your vocal cords are located, closes. This creates the noise of air expelled from your lungs, or the “hic” sound that feels involuntary...

                               Leukocytes              White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. Details System Immune system Identifiers Acronym(s) WBC MeSH D007962 TH H2.00.04.1.02001 FMA 62852        All white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cell types are classified in standard ways; two pairs of broadest categories classify them either by structure (granulocytes...