Biology Section Bank

Question 1

<p>if a substrate requires phosphorylation, which enzyme is most likely to suppress it?</p>

Answer 1

<p>A phosphatase is an enzyme that removes a phosphate group from its substrate. This makes it likely to suppress the substrate.</p>

Question 2

<p>which components are made out of actin?</p>

Answer 2

<p>Microfilaments are made out of actin.</p>

Question 3

<p>Which amino acids are the most likely to be phosphorylated?

The amino acids with the a free what group? </p>

Answer 3

<p>Within a protein, phosphorylation can occur on several amino acids. Phosphorylation on serine is the most common, followed by threonine. Tyrosine phosphorylation is relatively rare but is at the origin of protein phosphorylation signaling pathways in most of the eukaryotes.

OH GROUP

</p>

Question 4

<p>which amino acid is least likely to be found in the transmembrane domains?</p>

Answer 4

<p>The amino acids that are not hydrophobic.

| </p>

Question 5

<p>What are the hydrophobic amino acids?</p>

Answer 5

<p>lycine (Gly), alanine (Ala), valine (Val), leucine (Leu), isoleucine (Ile), proline (Pro), phenylalanine (Phe), methionine (Met), and tryptophan (Trp). </p>

Question 6

<p>Alanine contains what type of side chain?</p>

Answer 6

<p>An unbranched alkane, just a methyl side chain.</p>

Question 7

<p>The stereochemical designators alpha and beta distinguish between?</p>

Answer 7

<p>epimers (L and D configurations) only at anomeric carbons</p>

Question 8

<p>Which solution would have the greatest osmotic pressure?</p>

Answer 8

<p>The one with the highest concentration and the one that can dissasociate into the most ions.</p>

Question 9

<p>In order for a southern blot to be useful, the mutation should either ?</p>

Answer 9

<p>Create or eliminate a restriction site, most of them are palindromes.</p>

Question 10

<p>DNA from a retroviral will be the same as?</p>

Answer 10

<p>The original viral genome will be the same as the trasncribed mRNA.</p>

Question 11

<p>Competitive inhibition can be determined in what way?</p>

Answer 11

<p>Through rate experiment by applying the principles of Michaleis-Menten.

Keep the enzyme concentration constant, vary the substrate concentration, and either include or exclude the inhibitor</p>

Question 12

<p>ow much would a monomer of 288 amino acids weight approximately? A tetramer? Per amino acid?</p>

Answer 12

<p>The average weight for an amino acid is 110 Da. A 288 amino acids will weight 32kDa. a tetramer would be 128kDa</p>

Question 13

<p>A denaturing agent and reducing in gel electrophoresis would affect?</p>

Answer 13

<p>Denaturing agent will disrupt the interactions between monomers. A reducing agent will only disrupt any disulfide bonds.</p>

Question 14

<p>In an experiment the Y-axis represents the? Where as the x-axis represents the?</p>

Answer 14

<p>The y-axis is the dependent variable. The x-axis is the independent variable.</p>

Question 15

which amino acids are the polar ones?

Answer 15

Polar amino acids include serine, threonine, asparagine, glutamine, histidine and tyrosine.

Question 16

<p>Repeat question 31 bio</p>

Answer 16

<p>31</p>

Question 17

<p>A Hill coefficient greater than 1 means that?

If the Hill coefficient is essentially one it means that?</p>

Answer 17

<p>If the Hill coeficient is greater than one (2.25 was the example) it shows cooperativity.

If is essentially one (1.01 was the example) it does not show cooperativity. </p>

Question 18

<p>What is the Hill coeficient and what does it measure?</p>

Answer 18

<p>The hill coefficient measured the degree of cooperativity of an enzyme.

cooperativity is a phenomenon displayed by systems involving identical or near-identical elements, which act dependently of each other, relative to a hypothetical standard non-interacting system in which the individual elements are acting independently. One manifestation of this is enzymes or receptors that have multiple binding sites where the affinity of the binding sites for a ligand is apparently increased, positive cooperativity, or decreased, negative cooperativity, upon the binding of a ligand to a binding site. For example, when an oxygen atom binds to one of hemoglobin's four binding sites, the affinity to oxygen of the three remaining available binding sites increases; i.e. oxygen is more likely to bind to a hemoglobin bound to one oxygen than to an unbound hemoglobin. This is referred to as cooperative binding.[1]</p>

Question 19

<p>Describe the Lineweaver burk plot and variables for each of the inhibitors.</p>

Answer 19

<p>Good</p>

Question 20

What is one of the amino acids that contain an amide as part of its side chain?

Answer 20

Glutamine

Question 21

What is the strucutre of GTP?

Answer 21

Look it up

Question 22

Which amino acid is similar in size to serine and cannot be phosphorylated?

Answer 22

Alanine. It can choosen a s substitude if that is what you want.

Question 23

Different combination of exons produce?

Answer 23

Different protein isoforms.

Question 24

Ovarian cells are what type of cells? Osteoclasts?

Answer 24

Epithelial and connective.

Question 25

Hormones that must bind transport protein are what type of hormones?

Answer 25

Steroid proteins.

Question 26

If more than one band appear on the SDS-PAGE under reducing conditions this means that?

Answer 26

Reducing condition on a SDS-PAGE are used to cleave disulfide bonds.

So if a reducing condition was used and it led to two bands, it means that at least one disufide bond is present and in the protein and the bond(s) hold two separate subunits of different masses.

Question 27

Phosphodiester bonds link?

Answer 27

Adjacent nucleotides in DNA.

Question 28

An enzyme is more effectively inhibited by uncompetitive inhibitors when?

Answer 28

The substrate and the inhibitor is increased. This is because uncompetitive inhibitors bind to the ES complex so the substrate needs to increase as well to have more ES complexes.

Question 29

A signal sequence domain is required for?

Answer 29

Proteins that are directed towards secretory pathways.

Question 30

Gln and Asn are both?

Answer 30

glutamine and asparigine are polar aminoacids

Question 31

which method helps separate proteins based on charge?

Answer 31

Isoelectric focusing and Ion-exchange chromatography

Isoelectric Focusing separates proteins based on their isoelectric point (the pH at which the net charge of the protein is zero).

Ion exchange chromatography sperates proteins based on their net charge.

Question 32

SDS-PAGE separates proteins based on their? and affinity chromatography separates them on?

Answer 32

SDS-PAGE separates proteins based on their mass.

Affinity chromatography separates proteins based on their interactions with specific ligands.

Question 33

During the conversion of alpha-ketoglutarate to axaloacetate in the citric acid cycle how many moleciles of reuced electron carrier are generated?

Answer 33

THREE. Tow NADH and one FADH2

Question 34

Glucose-6-phosphate is used in both?

Answer 34

Gluconeogenesis and glycogenolysis. It catalyses the final step of both processes.

Question 35

Catalytic efficiency in the absence of Kcat can be calculated by?

Answer 35

Vmax/Km

Question 36

which amino acid would interact with D?

Answer 36

Arginine

Question 37

Which enzymes are likely used in cDNA cloning? Which one would not?

Answer 37

DNA polymerase, DNA ligase, Reverse Transcriptase

RNA polymerase

Question 38

The increase of the Kd by a amino acid substitution results in?

Answer 38

decreased stability of the protein. Also changing the an aromatic amino acid like tryptophan (W) for a polar but not aromatic will result in the decreased stability due to the elimation of a pie-stacking interaction with the side chain of W.

Question 39

which compounds are used as starting materials in gluconeogensis?

Answer 39

Lactate, oxaloacetate, and α-ketoglutarate.

Question 40

Following glucagon binding to its receptors it results in what? and and it also results in what?

Answer 40

following glucagon binding to its receptors it results in activation of its coupled G protein, activates adenylate cyclase and the protein kinase A, and the level of cAMP are all increased.

Activation of the G protein promotes the dissasociation of bound GDP and its exchange for GTP on the alpha subunit.

Question 41

The rate limiting step of in glycogen breakdown (glycogenolysis) is done by?

Answer 41

Glycogen phosphorylase.

Question 42

How are glucose polymers in liver (glycogen) formed by glycosidic bonds?

Answer 42

The glycosidic bonds between glucose molecules in glycogen are through α(1–>4) linkage linearly and α(1–>6) linkage at branch points

Question 43

Which compounds are gluconeogenic precursors and which is not?

Lactate, Glycerol, oxaloacetate, phosphogluconate

Answer 43

Lactate, Glycerol, and oxaloacetate are gluconeogenic precursors.

phosphogluconate is involved in the pentose phosphate pathway and is not a precursor or substrate of gluconeogenesis.

Question 44

A reversible reaction catalyzed in the forward direction by a kinase can be catalyzed in the reverse direction by which type of enzyme?

Answer 44

Phosphatase, which removes the phosphate whereas kinases add them.

Question 45

Increased activity of succinyl-CoA synthase will most likely result in?

Answer 45

Decreased levesl of succynil-CoA given that this is the substrate. It will also result in greater level of the reaction products which are succinate and GTP.

Question 46

The pentose pathway results in the generation of between other compounds?

Answer 46

NADPH, which is utilized in reductive reactions.

Question 47

The Vmax of a reaction is altered by which inhibitors?

Answer 47

Noncompetitive, uncompetitive, and mixed.

And not by the competitive inhibitor.

Question 48

Define mixed inhibitors.

Answer 48

is called “mixed” because it can be seen as a conceptual “mixture” of competitive inhibition, in which the inhibitor can only bind the enzyme if the substrate has not already bound, and uncompetitive inhibition, in which the inhibitor can only bind the enzyme if the substrate has already bound.

Question 49

Mixed inhibitors effect on Km and Vmax?

Answer 49

Always decreases Vmax and may increase or decrease Km.

Question 50

lipoic acid is a cofactor for the enzyme? which catalyses the conversion of?

Answer 50

acid is a cofactor for the enzyme pyruvate dehydrogenase and it catayses the conversion of pyruvate to acetyl_CoA

Question 51

For any given gene, the template strand is complementary to?

Answer 51

The coding strand and the mRNA.

Question 52

Southern blotting is used for?

Answer 52

It is used to detect a particular sequence in a sample of DNA. Not useful for analyzing gene expression.