AP Biology Notes_ Enzymes and Metabolism

What is the active site of an enzyme?

A 3-D pocket within the enzyme's structure where substrate molecules can be held to facilitate a reaction.

What are the two models of enzyme-substrate interaction?

Lock-and-key and induced fit models.

How do enzymes affect activation energy?

Enzymes lower the activation energy of a reaction.

What is feedback inhibition in enzymatic regulation?

It is when the end product of a biochemical reaction blocks the activity of the original enzyme.

What are the two main parts of photosynthesis?

The light cycle and the dark cycle (Calvin or Calvin-Benson cycle).

What is the function of chloroplasts and mitochondria in living systems?

Chloroplasts perform photosynthesis, while mitochondria perform cellular respiration.

What are the stages of cellular respiration?

Glycolysis, pyruvate decarboxylation, the citric acid cycle, and the electron transport chain.

What is endocrine signaling?

The secretion of chemical messengers for widespread distribution throughout the entire organism.

Define metabolite in the context of cellular respiration.

Cellular respiration is an efficient catabolic pathway that yields ATP.

What distinguishes aerobic respiration from anaerobic respiration?

Aerobic respiration requires free oxygen, while anaerobic respiration does not.

What is the function of Rubisco in photosynthesis?

Rubisco accepts oxygen in place of carbon dioxide and fixes carbon in photosynthetic organisms.

What is the process of photophosphorylation?

The synthesis of ATP using radiant energy absorbed during photosynthesis.

Define the term 'autotroph.'

An organism that utilizes energy from inorganic materials to manufacture organic materials.

What is the role of coenzymes in enzymatic reactions?

Coenzymes are organic cofactors required for enzyme activity.

What is the difference between light reactions and dark reactions in photosynthesis?

Light reactions produce energy in the presence of light, while dark reactions (Calvin cycle) make sugars without light.

What are gap junctions?

Pores in cells that allow for direct cell-to-cell communication.

What is lactic acid fermentation?

A type of anaerobic respiration found in fungi, bacteria, and human muscle cells.

What is oxidative phosphorylation?

Formation of ATP from energy released during the oxidation of substances in aerobic respiration.