AAMC Section Bank B/B and C/P Missed Topics

Phosphodiester bond

What type of interaction does not contribute to the stabilization of the tertiary structure of a protein?

Peptide hormone

• A type of hormone that is comprised of amino acids and can exert effects on target cells by binding to specific receptors.

• hydrophilic and soluble in blood

Steroid hormone

• A type of hormone derived from cholesterol that is hydrophobic and can pass through cell membranes to bind to intracellular receptors.

To determine if VopC affects Rac expression levels. It is important to know the total amount of Rac that is affected by the strain being used. If the Rac expression is upregulated in one strain and not another, this will affect interpretation of the gel results.

Why was the total amount of Rac measured in experiment 2?

Phosphorylation by PKA can partially activate CREB327

Which statement about CREB327 phosphorylation is supported by the data in the graph?

connective tissue

What type of tissue are osteoclasts?

epithelial tissue

What type of tissue are ovarian cells

The substrate concentration is increased and the inhibitor concentration is increased. This is because uncompetitive inhibitors bind their target enzymes only when the substrate is first bound to the enzymes. The uncompetitive inhibitor will work most effectively when the substrate concentration is the highest.

An enzyme is more effectively inhibited by uncompetitive inhibitors when_____?

Energy of a photon is E=hc, but if it has a work function (some number)eV then do hc-(some number)eV

Kinetic energy of a photon equation

Add 0.1 M NaOH(aq) to quench unreacted anhydride. Then add diethyl ether and separate the layers. The amine can be obtained from the ether layer by evaporating the solvent. Extraction with aqueous base will hydrolyze and extract both of these into the aqueous layer, leaving the neutral amide in the ether layer.

What extraction procedure will completely separate an amide from the by-product of the reaction between an amine and excess carboxylic acid anhydride?

Phosphatides

Compound 1 is apart of what class of lipid molecules?

Triacylglycerols

A type of lipid composed of three fatty acid chains esterified to a glycerol backbone.

Pyrophosphates

Compounds containing two phosphate groups linked together, usually involved in energy transfer.

Phosphatides

Phospholipids that contain a glycerol backbone, two fatty acid tails, and a phosphate group, playing a key role in cell membrane structure.

Phosphonic acids

Organic compounds containing a phosphorus atom bonded to a carbon atom and two oxygen atoms, often used in agriculture as herbicides and in biochemical applications.

Liposomes prepared from compound 1 are under kinetic control but those prepared from compound 2 are under thermodynamic control. This is because when compound 1 is “stable to mixing” it is just sitting there, so it is under kinetic control. Compound 2 liposomes freely broke apart, rearranged themselves, and equilibrated to a brand new size based on the final concentration. Because this system is capable of completely restructuring itself to find its lowest-energy, most stable equilibrium state, it is operating under thermodynamic control.

What does the behavior of liposomes prepared from compounds 1 and 2 upon mixing indicate about the energetics of their transformations?

kinetic control

A situation where the reaction pathway is determined by the rate of reaction and not by the stability of the products, often leading to the formation of products that are not in their most stable state.

thermodynamic control

A condition in which the outcome of a reaction or process is determined by the stability of the products, leading to the formation of the most thermodynamically stable product over time.

[Ar]3d⁷ This is because Co(II) is a dication and is formed from the atomic element by the loss of two 4s electrons. As a consequence, only seven 3d electrons remain in the valence shell.

What is the electron configuration of the Co(II) center found in vitamin B12?

Transferase. This is because kinases catalyze the transfer phosphate groups from ATP to target proteins and are classified as transferases. A kinase is a specific type of transferase.

The ATP dependent phosphorylation of a protein target is catalyzed by which class of enzyme?

pRB induction requires BAX, but not BAK, for TNFa-stimulated apoptosis. This is because pRB induction enhanced TNFa-stimulated apoptosis in both WT and Bak -/- cells. However, there was no effect in Bax -/- cells, indicating that BAX is required for TNFa-stimulated apoptosis.

Which statement is best supported by the data shown in figure 1?

Use of a fluorescent probe that hybridizes to rb transcripts. This is least helpful because the fluorescent probe that hybridizes to rb transcripts is tracking mRNA, not the finished protein.mRNA is transcribed in the nucleus and then translated by ribosomes in the cytoplasm. Virtually all mRNA transcripts are found in these same general areas. Tracking the mRNA will not tell you where the final protein goes after it is manufactured (e.g., whether it stays in the nucleus or travels to the mitochondria, as the researchers hypothesize).

Which experimental approach would be least effective to determine the localization of pRB within a cell?

nuclear localization domain

A sequence within a protein that directs it to the nucleus by facilitating its transport through the nuclear pore complex.

signal sequence domain

A region of a protein that directs it to specific cellular compartments, often guiding transport to the endoplasmic reticulum or other organelles.

DNA binding domain

A region of a protein that enables it to attach to specific DNA sequences, facilitating gene regulation and transcription.

Protein binding domain

A region of a protein that facilitates interaction with other proteins, often playing a crucial role in signaling pathways and cellular function.

• Hydrophobic amino acids. This is because the polar and charged amino acids most likely interact with water molecules in cytosol and would not be involved in protein protein interactions. The side chains of hydrophobic amino acids are free and most likely participate in the dimerization.

• Hydrophobic Effect!

Which amino acids are most likely present at the dimerization interface of STAT3 proteins?

• Answer: Isoelectric focusing and ion-exchange chromatography.

• SDS-PAGE separates proteins based on their mass

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

Which methods separate proteins based on their charge?

Three. 2 molecules of NADH and one molecule of FADH2

How many molecules of reduced electron carrier are generated during conversion of α-ketoglutarate to oxaloacetate in the citric acid cycle?

Glucose-6-phosphatase

Which enzyme is used both in gluconeogenesis and glycogenolysis?

Isoenzyme I

II, II, and IV

Based on the data presented in Table 1, which amino acid residues of PRR are involved in binding to prorenin?

• Higher ROS levels = increased blood pressure

• Lower ROS levels = decreased blood pressure

• reverse transcriptase

• DNA polymerase

• DNA liage

Which enzymes are used in cDNA cloning?

Glycogenolysis

The process of breaking down glycogen into glucose-1-phosphate for energy production in cells.

Gluconeogenesis

The metabolic process of synthesizing glucose from non-carbohydrate precursors, such as pyruvate, lactate, or amino acids.

1. Lactate

2. Oxaloacetate

3. α-Ketoglutarate

• These are used as starting materials in gluconeogenesis

After the depletion of hepatic glycogen in newborns, which compounds can be used as precursors to sustain the blood glucose level?

1. Acetyl-CoA

2. Lactate

3. Oxaloacetate

4. α-Ketoglutarate

Glycogen is formed by glycosidic bonds between glucose molecules through alpha (1—>4) linkage linearly and alpha (1—>6) at branch points.

The initial source of energy replacement in the liver of newborn infants is formed by glycosidic bonds between glucose molecules through:

• Increased levels of succinate

• increased levels of GTP

Under physiological conditions, increased activity of succinyl-CoA synthetase will most likely result in ___?

NADPH, which is used as a reductive agent in cellular respiratory processes

The pentose phosphate pathway results in the generation of:

Glucose-6-phosphate dehydrogenase

In the pentose phosphate pathway, which enzyme catalyzes the production of 6-phosphogluconolactone?

Southern blotting — Because southern blotting is a technique used to detect a particular sequence in a sample of DNA.

What technique cannot be used to analyze gene expression?

Western blotting, northern blotting, reverse transcription PCR

What techniques can be used to analyze gene expression?