I think the correct answer from the choices listed above is option D.It is the NH2 group that is present in amine compounds. Amines<span> are formally derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group.</span>
The major purpose(s) of mitosis is for growth and to replace worn out cells.
The basic structure of a steroid differ from other macromolecules such as carbohydrates by having a four ring structure whereas a carbohydrate do not have. A steroid is a group of organic substances which has four rings that are arranged in a certain configuration. Examples are testosterone, estradiol and lipid cholesterol. It will always have seventeen carbon atoms in its structure. Carbohydrates, on the other hand, are a group of organic substances that consist carbon, hydrogen and oxygen atoms typically in a 2:1 ratio of the hydrogen and oxygen atoms. So, it would have an empirical formula of Cx(H2O)y.
1. The correct answer is: The viral envelope proteins interact with CD4 and a co-receptor on the cell membrane.
Binding and entering the host cell are the first steps of the HIV virus infection. So, these steps play a major role in determining the ability of HIV to degrade the human immune system. Binding of HIV to CD4+ T lymphocytes (express chemokine receptors CCR5 and CXCR4 called co-receptors) triggers the fusion of the viral and host cell membranes, initiating infection (viral core gets into the cytoplasm).
Attachment of the virion can be:
• Nonspecific-envelop protein of the virus (Env) binds to cell-surface heparan sulfate proteoglycans
• Specific-Env binds to integrin.
2. The correct answer is: Activation of the host cell by cytokines, growth factors, or antigens.
After the viral capsid enters the cell, single-stranded RNA genome is released from the attached viral proteins and copied it into a complementary DNA (cDNA) molecule thanks to an enzyme called reverse transcriptase. Next step is the integration of the viral DNA into the host cell's genome. This process is done by another viral enzyme called integrase. The integrated DNA is transcribed into RNA and then translated into proteins that will help the package of new viruse particles.
3. The answer is: false
Reverse transcriptase is an enzyme that catalyzes the formation of DNA from an RNA template. Since the genome of the virus (HIV) is single stranded RNA, reverse transcriptase copies it into a complementary DNA (cDNA) molecule. Thanks to this enzyme, formed cDNA can be integrated into host’s genome. Because of this proprety, antiretroviral drugs used to treat HIV infection work as reverse-transcriptase inhibitors.
I think respiration and reproduction
