Biology Assignment, biology homework help


A. Fill in the blanks with the most appropriate words. Each blank represents one word. Each question is worth two points. (20 points)

1.The voltage difference across the membrane is referred to as the


2._________________________________________________________ uses energy to

move solutes across a membrane against the concentration gradient.

3.Coated pits are “coated” with a protein called _____________________________.

4.Neurons pass signals to _________________________,________________________

and other neurons.

5.Plant cells engage in local signaling through direct connections with each other by

means of __________________________________________.

6.One of the three stages of cell signaling, ___________________________________, is

usually a complex series of steps that interprets a signal for the cell.

7.A chemical such as a hormone, known as the “signal” is also known as the


8. The signal’s first contact with the cell is via a(n) ____________________________

________________________________ (two blanks) located on the plasma membrane.

9. In the G-coupled Protein Receptor model that we discussed, the activated G protein in turn

activates the enzyme ____________________________________________________.

10. The function of the enzyme mentioned in question 9 is to convert ATP to a chemical that

in turn activates another enzyme called


B. Answer the following questions in one or two sentences. Remember that the answer must be in your own words. If it is too much like someone else’s answer or a passage from the text, you will not receive credit. Draw pictures if you wish, but you will be graded on the WORDS.

1. Explain how co-transport works.

2. Explain the difference between pinocytosis and phagocytosis. Be mindful of the warning given you in the video about the use of terms.

3. In what way are paracrine signaling and synaptic signaling different from each other?

4. What is second messenger? Why is it called that?


1. Testosterone passes through the plasma membrane and binds to a receptor protein in the


2. Some channel proteins are activated when the signal binds to them, opening a gate. A signal

that binds to a protein this way is called a________________________.

3. In some trends deductions, a protein kinase will be activated by ATP. This protein kinase then

gets involved in activating another protein kinase with ATP. This process may go on for

several protein kinase molecules, in a process called a(n)


4. Transcription is DNA making RNA. A cell signal that ultimately influences transcription

would ultimately finish its transduction process by activating a transcription factor in the