SA node has Prepotential or pacemaker potential which is the gradual potential rise from the resting membrane potential to threshold  ( -40 mV) & this occur spontaneously.

TLS Online TPP Program

#Id: 3213

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 3214

#Unit 4. Cell Communication and Cell Signaling

Amplification (i.e., abnormal DNA replication) of a DNA segment including a proto-oncogene, leading to overproduction of the encoded protein.

TLS Online TPP Program

#Id: 3216

#Unit 4. Cell Communication and Cell Signaling

Carcinogens

1. Environmental DNA-damaging agents

2.Prevent DNA damage from being repaired with high fidelity

TLS Online TPP Program

#Id: 3218

#Unit 4. Cell Communication and Cell Signaling

Chemical carcinogens classified into two general categories:
1. Direct-acting carcinogens
2. Indirect-acting carcinogens

TLS Online TPP Program

#Id: 3220

#Unit 4. Cell Communication and Cell Signaling

Direct-acting carcinogens

Highly reactive compounds that can react with and modify nucleotide bases in DNA so as to distort the normal pattern of base pairing

TLS Online TPP Program

#Id: 3221

#Unit 4. Cell Communication and Cell Signaling

Direct-carcinogens includes:

Ethylmethane sulfonate (EMS)
Dimethyl sulfate (DMS)
Nitrogen mustards