Final Exam Flashcards
(90 cards)
You are a pathologist in training. You look at a slide that contains a skin lesion. There are many abnormal cells that have a diameter of approximately 3 um.
You predict these are:
invading prokaryotic cells causing an infection
What is true of electron microscopes?
they require that samples be treated with solutions that contain metal before imaging
Which is true about eukaryotes and prokaryotes?
eukaryotes CONTAIN mitochondria, but prokaryotes do NOT
In water, polar covalent bonds are found:
between a hydrogen atom and an oxygen atom WITHIN a water molecule
Condensation reactions _____________.
create new water molecules
What is the correct expression that accurately describes the calculation of pH?
pH = -log10[H+]
How does the chemical structure of phospholipids suit their function in the cell membrane?
-self assemble so that polar head groups associate with water molecules through hydrogen bonding
-polar molecules cannot easily cross as the interior of the membrane bilayer is hydrophobic
-self assemble so that water is excluded from the interior of the bilayer (hydrophobic exclusion
-aqueous solution within a cell is mostly separated from the external environment because the phospholipids form a bilayer
Your temperature is 100 F, give or take a few degrees.
What is true of this observation?
the heat released from your body contributes to the increasing disorder in the universe
A cell breaks down molecules to obtain energy.
What is a characteristic most likely associated with this process?
exergonic, catabolism, hydrolysis reactions
Imagine you are studying acetylcholinesterase activity isolated from rat brains. You determine that an acetylcholinesterase-catalyzed reaction has a deltaG = -80 kcal/mol. You decide to REPEAT the experiment and add TWICE as much of the enzyme.
What do you predict the deltaG to be?
-80 kcal/mol
*STAYS THE SAME!
A drug (Lisinopril) sits directly in the active site of an enzyme so that the normal substrate cannot bind.
What is this type of enzymatic inhibition called?
Competetive inhibition
What do protein alpha helices involve?
hydrogen bonding between carboxyl (carbonyl) and amino groups of different amino acids
What are proteins that are allosteric?
their activity is regulated by shifting between 2 or more confirmations (shapes)
Disulfide bridges on the same polypeptide chain are examples of a protein’s ______________.
HINT: structure
tertiary
A protein such as hemoglobin, which is composed of more than one polypeptide chain has ______________ structure.
quaternary
Within the subunits of hemoglobin, there is specific coordination of a heme (iron-containing) groups that are part of the proteins O2-binding ______________.
domain
Does a Kinase add or remove a phosphate group. What does Phosphatase do?
Kinase ADDS phosphate
Phosphatase REMOVES phosphate
TRUE/FALSE: Protein domains are only found in proteins with quaternary structure
False
Consider a 3-letter sequence of DNA that is transcribed to mRNA and eventually translated to become an amino acid.
When would a mutation in this DNA be LEAST likely to cause a problem?
if both the mutant and original amino acids are both non-polar
In the test zone of an ELISA Assay (e.g. pregnancy test), what is NOT present?
polyclonal antibodies that are specific to monoclonal antibodies
TRUE/FALSE: Spontaneous reactions occur rapidly even when no enzyme is present
False
TRUE/FALSE: If a molecule if reduced, the molecule has acquired more electrons
True
TRUE/FALSE: A biological example of the first law of thermodynamics is the proton gradient in mitochondria driving ATP synthesis in oxidative phosphorylation
True
TRUE/FALSE: Enzymes may denature when the salt concentration of a solution is changed
True
