Final Exam Comprehensive Questions

Biology 189 Final Exam Comprehensive Questions 10 pts each

For the following questions I want you to be complete but not overly wordy. Please make them only as long as you need to explain the answer. But? be complete!

1) Explain the difference between hydrophobic and hydrophilic molecules in terms of their molecular structure. Be complete?

The hydrophobic molecular structure is comprised of a hydrocarbon tail which make it repel water. The hydrophilic head are comprised of a phosphate group which makes it have an affinity towards water.That is why the hydrophilic heads are on the oustide of a phospholipid bilayer and the hydrophobic tails are on the inside.

2) Describe the chemical composition and configuration of enzymes and discuss the factors that modify enzyme structure and/or function.

Enzymes are mostly proteins made up of amino acids. They have the primary,secondary,tertiary,and quaternary structure. When there is a pH change that is extreme it can cause there to be an imbalance in the amino acids which causes bonds to be broken.An increase in ions can cause denaturation. Also temperature changes in the enzyme can lead to denaturation.

3) Cells transport substances across their membranes. For the following four types of cellular transport, choose TWO and describe the transport process and explain how the organization of cell membranes functions in the movement of specific molecules across membranes.


Osmosis is the diffusion of water across a selectively permeable membrane. It is crucial for there to be movement of water across a cell membrane and there has to be a balance between the cell and its environment.

Facilitated Diffusion

Facilitated Diffusion is a special carrier protein with a central channel that acts as a selective corridor which helps move certain molecules across the membrane. Without facilitated diffusion certain solutes would not be able to get into the cell.

4) A portion of specific DNA molecule consists of the following sequence of nucleotide triplets:


This DNA sequence codes for the following short polypeptide: methionine - leucine - glutamic acid - proline ? arginine

Describe the steps in the synthesis (formation) of this polypeptide (from DNA to protein) in sufficient detail that I am convinced that you understand! (This answer might need to be a little longer than the others? that?s ok!)

It is transcibed into mRNA AUG CUU GAA CCC AGG. tRNA have anticodons which carry certain aminoacids to one end which is assembled in the ribosome.There is then a peptide linkage formed which then turns into a polypeptide. The polypeptide shifts and forms and then is sent to it specific destination which is carried out by signals.

5) If Andy belongs to blood group, type O, he could NOT possibly have the following set of parents.

A. Type A mother and Type B father

B. Type O mother and Type B father

C. Type AB mother and Type O father

They could NOT be his parents because the mix of the two would result in either A blood or B blood

D. Type O mother and Type A father

E. None of the parents could produce a child with Type O blood

Explain your answer in detail.

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