Lysozyme is an enzyme that destroys bacterial cell walls. It does so by hydrolyzing the β(1→4) glycosidic linkages from N- acetylmuramic acid (NAM or MurNAc) to N- acetylglucosamine (NAG or GlcNAc) in cell wall peptidoglycans. The only functional groups in the immediate vicinity of lysozyme’s reactive center that have the required catalytic properties are the side chains of Glu 35 and Asp 52.

a- Glu perform reaction in its protonated state and Asp perform reaction in its deprotonated state. 

b- Glu perform reaction in its deprotonated state and Asp perform reaction in its protonated state. 

c- both in its protonated form

d- both in its deprotonated form 

Choose the correct option?

#Question id: 1998

#Unit 4. Cell Communication and Cell Signaling

Jenner successfully used cowpox virus as a vaccine against the virus that causes smallpox. Why was he successful even though he used viruses of different kinds?

#Question id: 1999

#Unit 4. Cell Communication and Cell Signaling

Which of the following would be most beneficial in treating an individual who has been bitten by a poisonous snake that has a fast-acting toxin?

#Question id: 2000

#Unit 4. Cell Communication and Cell Signaling

Which of the following is true of the successful development of a vaccine to be used against a pathogen?

#Question id: 2001

#Unit 4. Cell Communication and Cell Signaling

A researcher is analyzing the immune response of a patient following the patientʹs exposure to an unknown agent while out of the country. The patientʹs blood is found to have a high proportion of lymphocytes with CD8 surface proteins. What is the likely cause?

#Question id: 2002

#Unit 4. Cell Communication and Cell Signaling

What accounts for antibody switching (i.e., the switch of one B cell from producing one class of antibody to another antibody class that is responsive to the same antigen)?

#Question id: 2003

#Unit 4. Cell Communication and Cell Signaling

The number of MHC protein combinations possible in a given population is enormous. However, an individual in that population has only a couple of MHC possibilities. Why?