4.5energetics

What are the eight characteristics that define life?

Order, Reproduction, Inherited information base, Growth and development, Energy utilization/processing, Response to environment, Regulation/Homeostasis, Evolutionary adaptation.

What is the ultimate source of energy for most living things?

The sun.

How do photosynthesizing organisms contribute to the energy flow in ecosystems?

They capture the sun's energy and pass it on to other organisms in the form of food.

What are two forms of energy?

Potential energy (stored energy) and kinetic energy (energy in motion).

What does the first law of thermodynamics state?

Energy is never created or destroyed, only transformed.

What does the second law of thermodynamics state?

Energy transfer will always result in a greater amount of disorder in the universe.

What does entropy measure in a system?

The amount of disorder; greater entropy means greater disorder.

What happens to energy during its transformation according to thermodynamics?

Some energy is lost as the most disordered form of energy, heat.

What is an example of an endergonic reaction?

The linkage of simple sugars to form complex carbohydrates.

What happens in an exergonic reaction?

Energy is released, and the reactants contain more energy than the products.

What is ATP and its significance in living organisms?

Adenosine triphosphate (ATP) is the most important energy transfer molecule; it powers metabolic processes.

What is the ATP/ADP cycle?

A cycle where ATP donates a phosphate to become ADP and can regain a phosphate to reform ATP.

How do enzymes function as catalysts?

They lower the activation energy required to initiate a chemical reaction.

What types of reactions does ATP power?

Muscle contraction, nerve signal transmission, and various metabolic processes.

What is the difference between anabolic and catabolic reactions?

Anabolic reactions build up molecules and require energy, while catabolic reactions break down molecules and release energy.

What is the central dogma of molecular biology?

The process by which the information in genes flows into proteins: DNA ➔ RNA ➔ Protein.

What role does RNA play in the cell?

RNA serves as a messenger carrying instructions from DNA for controlling the synthesis of proteins.

What is the difference between DNA and RNA?

DNA is double-stranded and contains deoxyribose, while RNA is single-stranded and contains ribose.

What is a mutation?

A change in the DNA sequence that can affect genetic information.

What are the four nitrogenous bases in DNA?

Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).

What is a protein's primary structure?

The unique sequence of amino acids that make up a protein.

How do enzymes speed up chemical reactions?

By lowering the activation energy required for the reaction to occur.

What is the function of ribosomes in a cell?

Ribosomes are the sites of protein synthesis where mRNA is translated into amino acid sequences.

What is the significance of the genetic code?

It defines how sequences of nucleotides correspond to specific amino acids in proteins.

What is homeostasis?

The ability of an organism to maintain stable internal conditions despite changes in the external environment.