What is NOT produced during the citric acid cycle?

Which of the following is NOT part of the endomembrane system?

Which of the following is involved in direct reversal of DNA damage?

Which of the following is NOT found in a typical plant cell?

A cell does three main kinds of work.  They are chemical, mechanical, and:

Meselson and Stahl’s experiment examined the different models of DNA replication.  Below are the test tubes from the first replication cycle.  Which of the following test tubes would have provided evidence that the conservative model of DNA replication was the correct model for DNA replication?

HIV (Human Immunodeficiency Virus) infects a helper T cell by binding onto the CD4 membrane protein found on all helper T cells (a type of lymphocyte that is part of your immune system.)  However, to enter the cell, HIV also has to bind onto the CCR5 co-receptor protein.  There is much research now in creating a drug that blocks the binding of HIV to the CCR5.  Why?

In facilitated diffusion, the net movement of a molecules is:

The active site on an enzyme can lower the activation energy in several ways.  Which of the following is not one of those ways?

The purpose of the citric acid cycle is to generate energy from the break down of the acetyl group that is taken into the cycle and convert the intermediary molecules in the cycle back to: