Examples of Transcription Factors in AP Biology

📚 Quick Study Guide

• 🧬 Transcription factors are proteins that bind to DNA and regulate gene expression.
• 🔑 They can act as activators (increasing transcription) or repressors (decreasing transcription).
• 🌱 Examples include proteins with motifs like zinc fingers, leucine zippers, and helix-turn-helix.
• 🔥 Activators enhance transcription by helping RNA polymerase bind to the promoter.
• ⛔ Repressors block transcription by preventing RNA polymerase from binding.
• 🔬 Combinatorial control means multiple transcription factors work together to regulate a single gene.

Practice Quiz

1. Which of the following is a primary function of transcription factors?
   1. A) Replicating DNA
   2. B) Regulating gene expression
   3. C) Translating RNA into protein
   4. D) Transporting molecules across the cell membrane
2. A transcription factor that increases the rate of transcription is known as:
   1. A) A repressor
   2. B) An activator
   3. C) A silencer
   4. D) An insulator
3. Which structural motif is commonly found in transcription factors?
   1. A) Beta-barrel
   2. B) Alpha-helix
   3. C) Zinc finger
   4. D) Glycosylation site
4. What is the role of a repressor transcription factor?
   1. A) To initiate DNA replication
   2. B) To block RNA polymerase binding
   3. C) To enhance ribosome activity
   4. D) To repair damaged DNA
5. Combinatorial control of gene expression refers to:
   1. A) The use of a single transcription factor to regulate many genes
   2. B) The interaction of multiple transcription factors to regulate a single gene
   3. C) The simultaneous transcription and translation of a gene
   4. D) The regulation of gene expression by methylation
6. Where do transcription factors typically bind on the DNA?
   1. A) The terminator
   2. B) The promoter
   3. C) The start codon
   4. D) The enhancer
7. Which of the following is NOT a typical domain found in transcription factors?
   1. A) DNA-binding domain
   2. B) Activation domain
   3. C) Ligand-binding domain
   4. D) Ribosome-binding domain