Final answer:
BaP, a carcinogen in tobacco smoke, increases cancer risk by causing DNA mutations that may disrupt the cell cycle and prevent programmed cell death, leading to uncontrolled cell division.
These mutations often occur in genes like tumor-suppressor genes that normally regulate cell growth.
Step-by-step explanation:
How BaP Increases Cancer Risk
Benzopyrene (BaP), a potent carcinogen found in tobacco smoke, contributes to an increased risk of developing cancer by causing mutations in the DNA of cells. Tobacco smoke contains various carcinogens like BaP, acrolein, and nitrosamines which can bind to DNA, potentially causing mutations that either kill cells or disrupt normal cell functions.
Particularly concerning is the potential for mutations to inhibit programmed cell death, allowing abnormal cells to survive and proliferate into cancer cells.
Mutations and Cancer Development
Mutations in the DNA can influence the development of cancer by disrupting the normal cell cycle. These disruptions can prevent cells from undergoing apoptosis, the process of programmed cell death, leading to uncontrolled cell growth and division. Mutations typically occur in genes that regulate cell growth and division, such as tumor-suppressor genes, which when altered, contribute to the dysregulation of the cell cycle.
Impact of Carcinogens in Tobacco Smoke
Exposure to carcinogens in tobacco smoke, such as BaP, can lead to an increase in the rate of mutations during DNA replication. Cancers often arise due to mutations in tumor-suppressor genes and oncogenes, which control the cell cycle. This makes smokers and those exposed to secondhand smoke more likely to develop cancers of the lung, mouth, throat, bladder, and more, since the carcinogens act as environmental triggers for the onset of cancer.