Question

Hair that is too weak to hold a curl or may be completely?

Answer 1

Weak hair may struggle to maintain curls due to damage to its structural bonds. Temporary waves involve hydrogen bonds and can be affected by water, while permanent waves alter disulfide bonds for longer-lasting effects. However, overly weak or damaged hair may not hold either type of curl well.

Step-by-step explanation:

Hair that is too weak to hold a curl may be indicative of damage to the hair’s structure, specifically the disulfide and hydrogen bonds within the strands. Temporary waving of hair involves the disruption of hydrogen bonds, which can occur when water molecules penetrate the keratin strands. As the hair dries, new hydrogen bonds are formed, allowing the hair to maintain a new shape for a time. However, if hair is too weak, it may not be able to hold these new bonds effectively, resulting in an inability to maintain the desired curl.

On the other hand, a permanent wave creates curls by chemically breaking and reforming the disulfide bonds in the hair. This process typically allows for a longer-lasting curl as compared to a temporary wave. Nonetheless, if hair is overly damaged or weak, it might not be able to withstand the chemical process required for a permanent wave, and the hair may fail to hold the curl or could be further damaged.

Moreover, hair can also exhibit behaviors such as static electricity, as described in Figure 18.1, where an imbalance of electrical charge causes the hair to stand on end. This occurs due to the movement that strips electrons away, leaving the hair with an excess of positive charges, resulting in repulsion between the strands.

Answer 2

Hair's ability to hold a curl is related to the temporary or permanent alteration of hydrogen and disulfide bonds within the keratin strands. Temporary waves are due to water disrupting hydrogen bonds, while permanent waves are achieved by chemically altering disulfide bonds. Additionally, static electricity due to electrical charge imbalances can affect hair's behavior.

Step-by-step explanation:

Hair and Its Ability to Hold a Curl

When discussing hair that is too weak to hold a curl or may be completely unresponsive to styling, we're delving into the biology of hair and its structural properties. Temporary and permanent waves involve hair's ability to maintain a given shape after manipulation. In the case of a temporary wave, when hair gets wet, water molecules penetrate the keratin strands and disrupt some of the hydrogen bonds that maintain the hair's shape. As the hair dries, new hydrogen bonds form, allowing the hair to temporarily retain a new curl.

However, for a permanent wave, the process involves breaking and reforming the disulfide bonds within hair strands through a chemical treatment. Disulfide bonds are stronger and more resilient than hydrogen bonds, contributing to a more long-lasting change in hair structure.

It's also interesting to note that electrical charges can affect hair's behavior. For example, an imbalance of electrical charges, commonly known as static electricity, can cause hair strands to stand on end or repel each other. This phenomenon is due to the stripping away of electrons and a resultant excess of positive charges along each hair strand, as illustrated in Figure 18.1.