The sun emits ultraviolet light radiation which is the component of sunlight that is able to damage skin. Ultraviolet (UV) is a form of electromagnetic radiation with wavelengths between 10 to 400 nanometers, shorter than that of visible light but longer than X-rays. To put nanometers into perspective - A human hair is around 75,000 nanometers in diameter. There are sub-types of UV which define the wavelength size: Ultraviolet A - UVA - 400–315 nanometers Ultraviolet B - UVB - 315–280 nanometers Ultraviolet C - UVC - 280–100 nanometers Interestingly UVB is essential to synthesize Vitamin D. UV light is able to damage DNA. This results with humans cells (typically skin cells) to attempt to repair themselves. As a result sometimes genetic mutations arise - some of which give the cell the ability to divide more frequently (cancer). The process of UV damage is shown in the image below. Although advertises I'm sure would love you to believe that Vitamin D should always be gained from th...
The famous philanthropist Oprah has advised thousands of women across the globe on how to find ' the one '. But Oprah never mentioned the good genes hypothesis. The good genes hypothesis was originally proposed in the 1980s and propagates the idea that observed mates are selected by their ability to pass on genes that increase reproductive success. How might it work? An organisms phenotype is determined by its genotype. Meaning your body observable properties (organs, tissues and cells) are determined by their genes. Therefore if your face is asymmetrical then more mutations have arisen, making you a sub-optional candidate compared to a more symmetrical competitor, who is less prone to mutations. Many psychology studies have shown that greater symmetry has a relationship with attractiveness. Is the good genes theory well supported or true? Whilst it is an appealing hypothesis, a recent study with almost 5000 participants with varying degrees of facial symmetry fou...
The mitochondrial membrane is important for ATP synthesis ( oxidative phosphorylation ) to occur. Electron transport chains are situated on the inner mitochondrial membrane where electrons traverse the chain across proteins - causing protons to traverse into the mitochondrial matrix. Creating an electrochemical proton gradient. This is a very interesting topic and is best understood with an explanation of the JC-1 Dye. Explanation Mitochondrial membrane potential changes - depending on cellular events. The dye ' JC-1 ' is able to indicate mitochondrial membrane potential in different cells. If there is a negative charge inside mitochondria then the monomers express green fluorescence. If there is a positive charge inside mitochondria then the monomers form J-aggregates and now express red fluorescence. The ratio between red & green florescence shows the mitochondrial membrane potential. A low or negative mitochondrial membrane potential will show more green f...
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