differentiate alkenes and alkynes, cis isomers and trans isomers. Describe how cis-trans isomers are used for night vision

Rocky, this is a discussion question and you would do best to answer it and let us comment on your response. For the vision part, look up on the web or in your text/notes about vitamin A and cis-trans isomers.

To differentiate alkenes and alkynes, as well as cis and trans isomers, let's start with the basic definitions.

Alkenes:
- Alkenes are hydrocarbons with carbon-carbon double bonds (-C=C-).
- They are unsaturated hydrocarbons since they have fewer hydrogen atoms compared to their corresponding alkanes (saturated hydrocarbons).

Alkynes:
- Alkynes are hydrocarbons with carbon-carbon triple bonds (-C≡C-).
- Similar to alkenes, alkynes are also unsaturated hydrocarbons.

Now, let's move on to differentiating cis and trans isomers.

Cis-Isomers:
- Cis-isomers are a type of stereoisomer where atoms or groups are located on the same side of the molecule.
- In cis-isomers, there is restricted rotation around the double bond (or any other relevant bond), resulting in different arrangements of atoms or groups.

Trans-Isomers:
- Trans-isomers are another type of stereoisomer where atoms or groups are located on the opposite sides of the molecule.
- In trans-isomers, there is free rotation around the double bond (or any other relevant bond), allowing the atoms or groups to occupy opposite positions.

Now, let's discuss how cis-trans isomers are used for night vision.

Cis-Trans Isomers and Night Vision:
- In night vision technology, the compound used is called a "retinylidene derivative."
- Retinylidene derivatives contain a conjugated carbon chain with a double bond and a functional group known as a "chromophore."
- When light strikes the chromophore, it undergoes isomerization from its cis (bent) form to its trans (straight) form.
- This isomerization process triggers an electrical signal within the eye, allowing the individual to perceive light even in low light conditions.
- The trans isomer is the active form for vision.

In summary, alkenes and alkynes are hydrocarbons with carbon-carbon double and triple bonds, respectively. Cis and trans isomers are types of stereoisomers, with cis-isomers having atoms or groups located on the same side, and trans-isomers having them on opposite sides. In night vision, cis-trans isomerization of retinylidene derivatives leads to the perception of light in low light conditions.