Quiz 7 - Light in Microbial Control

UVC

1. shortest wavelength

2. does not reach the earth

3. harmless (unless you’re in space)

UVB

1. affects the top skin layer

2. makes you tan

3. redness, burns, skin cancer

UVA

1. longest wavelength

2. do not make you tan

3. skin aging, DNA damage

What are the two types of radiation?

1. ultraviolet

2. x-ray

Forms thymine dimers

UV radiation

What do thymine dimers do?

affect covalent bonds between adjacent thymines

X-rays

Cause single and double stranded breaks in DNA

What type of radiation can also alter nucleobases?

x-rays

What layer of the skin do UVB rays affect?

epidermis

What layer of the skin do UVA rays affect?

dermis

What light is used to form thymine dimers?

UV-C

What does UV-C light do?

forms thymine dimers between microbial DNA content and prevent proper DNA synthesis and bacterial replication

How do we typically sterilize environments to prevent microbe contamination and sterilize a surface?

use non-ionizing radiation

What UV radiation is more dangerous to us and has a higher energy?

UV-C