Fundamentals of Chemistry Quiz

Sterol lipids possess a rigid and hydrophobic ring system, while their hydrophilic polar hydroxyl group interacts with water.

The hydrophobic tails of lipids interact to minimize contact with water, while their hydrophilic heads face outward and interact with water molecules and ions.

The ability of a lipid bilayer to maintain fluidity is influenced by the types of lipids present. Less dense packing leads to greater fluidity.

Linear polymers containing coded information passed down through generations. They consist of nucleotides, each with a sugar, phosphate, and nitrogenous base.

The building blocks of nucleic acids, composed of a sugar, phosphate, and nitrogenous base.

The linear sequence of amino acids linked by peptide bonds.

Three-dimensional arrangement of a protein, formed by interactions between amino acid side chains.

Regular patterns of hydrogen bonding between the backbone carbonyl and nitrogen atoms in a polypeptide chain, forming structures like α-helices and β-sheets.

A chemical formula that represents the bonds between atoms in a molecule. Lines are used to show bonds, with carbons implied at the ends and intersections. Hydrogen atoms attached to carbons are not shown but are assumed to be present.

A theory that predicts the shapes of molecules based on the repulsion of electron pairs around a central atom. For example, a molecule with four electron pairs around a central atom will have a tetrahedral shape.

A theory that describes covalent bonds as resulting from the overlap of atomic orbitals. Sigma bonds are formed by end-to-end overlap, while pi bonds form from sideways overlap.

A theory that describes molecular orbitals as regions of space where electrons are likely to be found in molecules. It can be used to predict bond lengths and energies.

The amount of substance in a sample, equal to the number of particles (atoms, ions, molecules) divided by Avogadro's number.

The mass of one mole of a substance, expressed in grams per mole (g/mol).

The concentration of a solution expressed as the amount of solute (in moles) per unit volume of solution.

The concentration of a solution expressed as the mass of solute per unit volume of solution.

The concentration of a solution expressed as the volume of solute per unit volume of solution.

A technique for preparing dilute solutions from a concentrated stock solution. It involves taking a known volume of the stock solution and adding a specific amount of solvent to reduce the concentration.

The three-dimensional structure of a protein, determined by interactions between amino acid side chains. Includes interactions like hydrogen bonds, ionic interactions, dipole interactions, and disulfide bonds.

The arrangement of multiple polypeptide chains in a protein complex.

Proteins that assist in the proper folding of other proteins, ensuring they achieve their functional three-dimensional structure.

In globular proteins, amino acids with nonpolar side chains tend to cluster together in the interior of the protein, away from the aqueous environment.

In globular proteins, amino acids with polar and ionizable side chains tend to be on the exterior of the protein, interacting with the aqueous environment.

A method used to separate proteins based on their size. Smaller molecules pass through pores in the beads more easily, eluting later.

A method used to separate proteins based on their charge. Proteins interact with charged beads via ionic forces.

The pH at which a protein has a net charge of zero.

A condition where the blood pH is lowered due to excessive production of ketone bodies.

A series of protein complexes embedded in the inner mitochondrial membrane that transfer electrons from donors like NADH and FADH2 to oxygen, creating a proton gradient.

A mobile electron carrier in the ETC, shuttling electrons from Complex I/II to Complex III, contributing to the proton gradient.

A water-soluble protein in the intermembrane space that carries electrons one at a time from Complex III to Complex IV. It utilizes a heme group with iron for electron transfer.

A complex in the ETC that accepts electrons from NADH and transfers them to ubiquinone, pumping protons into the intermembrane space.

A complex in the ETC that accepts electrons from succinate and transfers them to ubiquinone, contributing to the proton gradient.

A complex in the ETC that receives electrons from ubiquinone and transfers them to cytochrome c, pumping protons into the intermembrane space.

A complex in the ETC anchored to the inner mitochondrial membrane that receives electrons from cytochrome c and transfers them to oxygen, forming water. This is the final step in the ETC, and it contributes to the proton gradient by pumping out protons.

A metabolic pathway responsible for breaking down glucose into pyruvate, generating energy in the form of ATP. It is activated when glucose levels are high or when energy is needed.

A metabolic pathway that generates glucose from non-carbohydrate sources, such as pyruvate or amino acids. It is activated when glucose levels are low.

The rapid regulation of glucose metabolism, primarily involving the activation or inhibition of enzymes involved in glycolysis and gluconeogenesis.

The slow regulation of glucose metabolism, primarily involving hormonal changes that alter the expression of genes coding for enzymes in glycolysis and gluconeogenesis.

The conversion of pyruvate to acetyl-CoA, reducing NAD+ to NADH and releasing carbon dioxide.

A metabolic pathway that occurs in mitochondria, responsible for oxidizing acetyl-CoA to carbon dioxide, generating ATP and reducing electron carriers like NADH and FADH2.

The process of producing ATP from the energy stored in NADH and FADH2 by using a series of protein complexes embedded in the mitochondrial membrane.

An alternative metabolic pathway to glycolysis found in some bacteria, generating ATP and reducing NADP+.

Cytochrome C is a protein that carries electrons from complex III to complex IV in the electron transport chain. It uses an iron atom in a heme complex to cycle between Fe(II) and Fe(III) oxidation states.

Complex IV, also known as cytochrome c oxidase, catalyzes the final step of the electron transport chain, reducing molecular oxygen to water. This process consumes protons from the mitochondrial matrix and pumps protons across the inner mitochondrial membrane, contributing to the proton gradient.

The proton-motive force is a form of energy generated across the inner mitochondrial membrane due to the proton gradient. This gradient has a chemical component (difference in proton concentration) and an electrical component (difference in charge).

ATP synthase is an enzyme that utilizes the proton-motive force to synthesize ATP. Protons flow through a channel in the enzyme, causing a rotation of its c subunit. This rotation drives conformational changes in the beta subunits, leading to ATP synthesis.

The malate-aspartate shuttle is a mechanism for transporting electrons from NADH in the cytosol to the mitochondrial matrix. It results in a net yield of 2.5 ATP per NADH molecule.

The glycerol phosphate shuttle is another mechanism for transporting electrons from NADH in the cytosol to the mitochondrial matrix. However, it results in a lower net yield of 1.5 ATP per NADH molecule.

Oligomycin is an inhibitor of ATP synthase. It prevents the flow of protons through the enzyme, thereby inhibiting ATP production.

The rotation of the c ring in ATP synthase drives a 120-degree rotation of the gamma subunit, which in turn triggers conformational changes in the beta subunits, leading to ATP synthesis.