The structure and function of neurons
By: Devon Begg
Neurons, also called nerve cells, are extremely important. They are mostly located in the brain. Without them, we cannot think, feel, or move our bodies. Life would not be possible without them. It would be unwise to say that neurons are simple. They are actually...
How sperm seek out an egg: The role of progesterone and ion channels
By: Daniel Cloud
Human fertilization occurs when the male reproductive cell, sperm, meets the female reproductive cell, an egg. The sperm of a male are produced inside the testes, and stored in the epidydymis. Ejaculation of sperm occurs through the head of the penis during during sexual intercourse...
How sperm seek out an egg: The role of progesterone and ion channels
By: Alicia M Prater PhD
Progesterone is a steroid hormone produced by the ovum and placenta, making it female-specific. Progesterone is responsible for preparing the uterus for pregnancy, but research published in the journal Nature in March 2011 identified another role for the hormone – conception. For decades mystery has...
Growth factors involved in cell cycle regulation
By: Alicia M Prater PhD
The cell cycle is a complex mechanism that results in cell growth and propagation. In eukaryotes, such as humans, the cycle is divided into G1, S, G2, and M phases, where M represents the process of mitosis (i.e. cell division), S represents “synthesis&rdquo...
By: Thirumahal Muthukrishnan
Eukaryotic animal cells are enclosed by an outer cell membrane unlike the plant cells that have an external cell wall. This plasma membrane is semi-fluid and selectively permeable in nature. It consists of a phospholipids’ bi-layer with integral proteins embedded on the outer or inner...
Introduction to meiosis
By: Lillian Mugwe
Meiosis is the type of cell division that is seen during the formation of gametes (sex cells). It consists of two successive divisions which are meiosis 1 and meiosis 2. In meiosis 1, the number of chromosomes is reduced by one-half and for this reason...
Understanding cell division
By: Lillian Mugwe
Life in living organisms starts as a single cell or zygote or spore. In multicellular organisms, the cell divides into two and continues to divide but in unicellular organisms, the cell divides into two separate daughter cells. Cell division is the development of an...
By: Dr Pandula Siribaddana
Exosomes are 30 – 90 nm vesicles secreted by mammalian cells and would be the result of late endosomes or multi vesicular bodies (MVB) coalescing with the cell membrane. According to scientists, the initial even in the formation of exosomes is the spontaneous invagination of...
Subnuclear bodies: Paraspeckles
By: Srikanth Radhakrishna
Paraspeckles are small, irregularly sized and unevenly distributed ribonucleoprotein (RNP) bodies found in the interchromatin space of mammalian cell nuclei. They are found between larger nuclear speckles and chromatin. They have an irregular sausage like shape. They are approximately 0.5-1 micrometer (one millionth of...
What are enzymes and what are they used for?
By: Lillian Mugwe
Enzymes are organic catalysts which are protein in nature. They are found in all living things and produced in all living cells. As catalysts, they speed up or reduce the rate of chemical reactions in the body without being used up themselves. There are two...

 

1 26 27 28 29 30 33