Teichoic Acids Are

question 9

Multiple Choice

Teichoic acids are:

• A)waxy substances that are found in some bacterial cell walls that make the cells resistant to toxic substances,including acids.
• B)glycerol- or ribitol-phosphate polymers that are combined with various sugars,amino acids,and amino sugars,which are a part of the cell wall of gram-positive bacteria.
• C)high-molecular-weight polysaccharides that coat some bacterial cells and protect the bacteria from attack by cells of the human defense system.
• D)hairlike,proteinaceous structures that extend from the cell.

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Definitions:

Silencer

A regulatory DNA sequence that can bind repressor proteins to inhibit the expression of a gene.

Insulator

A material that resists the flow of electric charge, used in various applications to protect against electric shock or retain heat.

Transcription Factor

Regulatory protein that influences transcription by binding directly to DNA; e.g., an activator or repressor.

Enhancer

DNA sequences that increase the transcription level of a gene they are associated with, enhancing gene expression.