Bioenergetics and ATP Production Quiz

A branched-chain polysaccharide made of alpha-D-glucose units. The linear part of the chain is linked by alpha-1,4 glycosidic bonds, while branches are formed by alpha-1,6 glycosidic bonds. A central protein called glycogenin serves as a core for glycogen synthesis.

Glycogen stored in skeletal muscle is primarily used to provide energy for muscle contraction. It's a local and fast source of glucose 1-phosphate, which can be quickly converted to glucose for energy production.

The liver stores glycogen as a reservoir for the entire body. It's essential for maintaining blood glucose levels, especially during fasting or between meals.

Glycogen synthesis involves converting glucose to glucose 1-phosphate, which is then activated by UDP to form UDP-glucose. UDP-glucose is then added to the growing glycogen chain.

Glycogen degradation breaks down glycogen into glucose 1-phosphate units. This process involves removing glucose units from the end of the chains and from the branching sites.

The pentose phosphate pathway (PPP) is a metabolic pathway that produces two important products: ribose 5-phosphate, used in the biosynthesis of nucleotides and nucleic acids, and NADPH, a reducing agent important in anabolic reactions and protection from oxidative stress.

The oxidative reactions of the PPP are irreversible and produce NADPH and CO2. They involve the conversion of glucose 6-phosphate to ribulose 5-phosphate.

The non-oxidative reactions of the PPP are reversible and involve interconversions of sugar phosphates. This allows the pathway to produce intermediates that can be used in other metabolic pathways, such as glycolysis, and to provide the necessary amount of ribose 5-phosphate for nucleotide synthesis.

A series of protein complexes in the inner mitochondrial membrane that facilitates the transfer of electrons from NADH and FADH2 to molecular oxygen, generating a proton gradient used for ATP synthesis.

A molecule that stores and releases energy in cells. It's composed of adenine, ribose, and three phosphate groups.

The process of generating ATP from the energy of the proton gradient across the inner mitochondrial membrane, driven by the electron transport chain.

The process of converting pyruvate to acetyl-CoA, connecting glycolysis to the citric acid cycle. It occurs in the mitochondrial matrix.

A series of reactions that takes place in the mitochondrial matrix, breaking down acetyl-CoA to carbon dioxide, generating ATP, NADH, and FADH2.

The process of synthesizing glucose from non-carbohydrate sources like pyruvate, lactate, or amino acids, primarily in the liver.

The breakdown of glycogen, a stored form of glucose, into glucose molecules. It occurs in the liver and muscle cells.

The process of storing glucose as glycogen, primarily in the liver and muscle cells. It occurs when blood glucose levels are high.

A metabolic pathway that converts glucose into ribose 5-phosphate, a precursor for nucleotide synthesis, and NADPH, a reducing agent used in biosynthesis.

A type of shuttle system that transfers reducing equivalents (electrons) from cytoplasmic NADH into the mitochondria, ultimately generating FADH2 within the mitochondria.

Bioenergetics is the study of energy transfer and utilization within living organisms. It helps understand whether a process is energetically favorable or not.

The change in free energy (ΔG) represents the energy difference between the initial and final states of a reaction. A negative ΔG indicates an exergonic (spontaneous) reaction, while a positive ΔG indicates an endergonic (non-spontaneous) reaction.

ATP (adenosine triphosphate) is the primary energy currency in cells. It releases energy when a phosphate bond is broken, forming ADP and inorganic phosphate.

Substrate-level phosphorylation refers to the direct transfer of a phosphate group from a high-energy substrate molecule to ADP to form ATP. This occurs during glycolysis.

Oxidative phosphorylation is the main way ATP is generated in cells. It takes place in the mitochondria and involves electron transport chain and chemiosmotic coupling.

Glycolysis is the breakdown of glucose into pyruvate in the cytoplasm. It yields a small amount of ATP and NADH.

Gluconeogenesis is the synthesis of glucose from non-carbohydrate sources, like pyruvate, lactate, or glycerol. This process occurs primarily in the liver and is important for maintaining blood glucose levels.

The pentose phosphate pathway is an alternative glucose metabolism pathway that produces NADPH and ribose 5-phosphate, crucial for nucleotide biosynthesis and reducing power in the cell.

Glycogenolysis is the breakdown of glycogen, a stored form of glucose, into glucose to supply energy. This process is essential during fasting or exercise.

Glycogenesis is the synthesis of glycogen from glucose, primarily in the liver and muscle. This process allows excess glucose to be stored for later use.

The citric acid cycle, also known as the Krebs cycle or TCA cycle, is a series of biochemical reactions in the mitochondria that oxidizes acetyl-CoA to produce electron carriers (NADH and FADH2) and carbon dioxide. The cycle also provides intermediates for various biosynthetic pathways.

Oxidative phosphorylation is the process by which ATP is produced using the energy released from electron transport chain. It is a major source of ATP in aerobic organisms.

The electron transport chain consists of a series of protein complexes located in the inner mitochondrial membrane. Electrons are passed along the chain, releasing energy used to pump protons across the membrane, ultimately leading to ATP production.

NADH and FADH2 are electron carriers that transfer electrons from glycolysis and the citric acid cycle to the electron transport chain. They carry high-energy electrons and donate them to the chain, contributing to ATP production.

Pyruvate is a three-carbon molecule produced during glycolysis. It can be further metabolized by the citric acid cycle to produce energy or used for other biosynthetic pathways.

Acetyl-CoA is a two-carbon molecule that enters the citric acid cycle. It is produced from pyruvate and is a crucial link between glycolysis and the citric acid cycle.