CMMB 443 Final Exam Actual Questions and Answers with complete solution

CMMB 443 Final Exam Actual Questions and Answers with complete solution Proteins are made in the cytoplasm but where are they needed in other parts of the cell? - answer- Cytoplasmic membrane proteins - Periplasmic proteins - Outer membrane proteins in G-ve cells - Extracellular proteins Define Translocation - answertransport of proteins into or through a membrane (e.g., into periplasm) Define Secretion - answerTransport of proteins to bacterial cell surface or to outside the cell Why target bacterial secretion systems to fight infections? - answerDisarm the virulence systems rather than kill the cells, so they can be eliminated by host immune system Many protein secretion systems are not in eukaryotes, so we can target these to control pathogenic bacterial infections What are the 4 types of Bacterial Protein Translocation/Secretion Systems? - answer1. Sec system 2. Tat system 3. Types I- VI 4. Type VII Where is sec system found? - answerFound in eukaryotes, bacteria, archaea Where is tat system found? - answerbacteria, archaea, plants What organism uses Types I- VI SS? - answerGram (-) What organism uses type VII SS? - answerGram (+) Mycobacterium What are the 4 key components of sec system? - answer1. Leader peptide 2. Chaperone protein (Sec B) 3. Membrane-bound 3 protein complex (SecYEG) 4. Cytoplasmic ATPase (SecA) Are proteins in sec translocated folded or unfolded? - answerUnfolded What does SecA + SecYEG form? - answerA translocase What is the role of the leader peptide in sec? - answerPlays important role for attaching and inserting a protein into/through a membrane Prevents protein from folding What end of the protein does the leader peptide attach to? - answerAt amino terminal end to be translocated What forms the preprotein? - answerprotein + leader pept