Author: Anonymous

Which molecules can move across the plasma membrane by simple diffusion?

Cats have a higher protein requirement than dogs.

For each type of gated channel listed below, select an appropriate stimulus that would trigger it from the pull-down menus on the right:

From the general equation for photosynthesis, explain where one of the reactants that plants take in is used, and explain where one of the products that plants give off is produced.  You can be as general as the half of the photosynthetic process for each.

The fastest method of cell-to-cell communication is via _________.

Use the pull-down menus to insert the best terms into the blanks that make these sentences true: When DNA is replicated, specialized enzymes will read the template strand and form the complementary daughter strand.  For example, when these enzymes identify a thymine nucleotide on the template strand, they will insert a(n) [blank1] nucleotide into the daughter strand, and vise versa.  Additionally, when these enzymes detect a guanine nucleotide in the template strand, they will insert a(n) [blank2] nucleotide into the daughter strand, and vise versa.

Many second messenger systems activate ________, which are enzymes that transfer a phosphate group from ATP to a protein. The phosphorylation of proteins sets off a series of intracellular events that lead to the ultimate cellular response. Type the best answer that completes this sentence into the text box below:

If a cell is stable at its resting membrane potential and a K+ channel opens, this will cause the cell to ________.

Use the pull-down menus to insert the best terms that make this sentence true: Once synthesized, the [blank1] of pre-mRNA are removed through a process called [blank2], which results in the formation of mature mRNA instructions for building a protein.

All signal molecules secreted by nerve cells (neuromodulators, neurotransmitters, and neurohormones) are collectively known as ________. Type the best answer that completes this sentence into the text box below: