test3

What do cells use to produce ATP from sugars and high-energy compounds?

Cells produce ATP by metabolizing sugars and other high-potential-energy compounds through pathways such as glycolysis, pyruvate oxidation, the citric acid cycle, and the electron transport chain.

What is glycolysis?

Glycolysis is the process that breaks down a six-carbon glucose into two three-carbon pyruvate molecules, yielding 2 ATP and 2 NADH.

Where does glycolysis occur?

Glycolysis occurs in the cytosol of both eukaryotic and prokaryotic cells.

What is the primary role of the citric acid cycle?

The citric acid cycle oxidizes acetyl CoA derived from pyruvate to CO2, reducing NAD+ to NADH and FAD to FADH2, and producing ATP.

What are the two main types of respiration?

Aerobic respiration uses oxygen as the final electron acceptor, while anaerobic respiration uses alternative electron acceptors when oxygen is not present.

What is fermentation?

Fermentation is a metabolic pathway that regenerates NAD+ from NADH, allowing glycolysis to continue in the absence of oxygen.

What are the products of lactic acid fermentation?

Lactic acid fermentation produces lactate and NAD+ from pyruvate by accepting electrons from NADH.

What are the products of alcohol fermentation?

Alcohol fermentation converts pyruvate to acetaldehyde and CO2, producing ethanol and regenerating NAD+.

What are catabolic pathways?

Catabolic pathways are metabolic pathways that break down molecules to release energy used to produce ATP.

What are the steps involved in cellular respiration?

The four main processes of cellular respiration are glycolysis, pyruvate processing, the citric acid cycle, and electron transport and oxidative phosphorylation.

What are the two types of energy in chemical reactions?

Kinetic energy (energy of motion) and Potential energy (stored energy in position/configuration).

What does mitochondria do in cells?

Mitochondria are the powerhouse of the cell and the site of ATP synthesis by oxidative phosphorylation.

What is Gibbs free energy (G)?

Gibbs free energy determines whether a reaction is spontaneous or requires added energy to proceed.

What is the difference between spontaneous and nonspontaneous reactions in terms of free energy?

Spontaneous reactions are exergonic (ΔG < 0) while nonspontaneous reactions require energy input and are endergonic (ΔG > 0).

What do exothermic reactions entail?

Exothermic reactions release heat energy and have a negative enthalpy, meaning products have less potential energy than reactants.

What role do enzymes play in chemical reactions?

Enzymes act as catalysts that accelerate chemical reactions by lowering the activation energy required.

What is the significance of the active site of an enzyme?

The active site is the location where substrates bind and is specific to a particular substrate for reaction.

What are competitive inhibitors?

Competitive inhibitors are molecules that compete with substrates for binding to an enzyme's active site, preventing the substrate from binding.

What is allosteric regulation of enzymes?

Allosteric regulation occurs when a molecule binds at a site other than the active site, changing the enzyme's shape and activity.

What is the difference between anabolic and catabolic pathways?

Anabolic pathways involve assembling small molecules into larger ones requiring energy, while catabolic pathways break down large molecules into smaller ones, releasing energy.