foundation definitions (lvl2 Flashcards
monomer (definition examples)
A monomer is a single molecule often linked to form a larger molecule known as a polymer. Monomers are link building blocks that can form a larger, more complex structure.
- monosaccharides, glycerol and fatty acids, nucleotides, and amino acids.
polymer (definition examples)
large molecules made by bonding (chemically linking) a series of monomers to create large chains of subunits.
polypeptide
Metabolism
interdependent and interacting chemical reactions occurring in living organisms. The metabolic processes in a cell consist of anabolic and catabolic reactions
anabolism
Anabolism is the synthesis of complex molecules from simpler molecules; it is a process that requires the input of energy. Anabolism includes the formation of macromolecules from monomers by condensation reactions.
catabolism
Catabolism is the breakdown of complex molecules into simpler molecules and includes the hydrolysis of macromolecules into monomers.
process which energy is released
catalyst (enzymes)
catalyst is a substance that increases the rate of chemical reactions but is not changed or used up in the reaction. Catalysts can catalyse chemical reactions over and over without being consumed, and are only needed in small amounts.
active site
a specific area composed of a few amino acids where the catalytic reaction takes place;
The active site is the result the folding of the polypeptide chain(s). The resulting (3D) shape that is formed by the polypeptide chain forms the active site, which is where the substrate interacts with the enzyme (Figure 2).
metabolic pathways
the action of enzymes combining with genes that convert a substrate molecule or molecules through a series of metabolic intermediates, eventually yielding a final product or products. For example, one metabolic pathway for carbohydrates breaks large molecules down into glucose
active site is located on enzymes
end product inhibition
when the end product of the chemical reaction turns off the production of its own product to avoid toxic buildup and is a non competitive irreversible inhibition
potential energy
the amount of energy that can be released from a molecule (more atoms = more potential energy)
activation energy
the minimum amount of energy required to cause a chemical reaction
enzymes lower activation rate
When the enzyme and substrate(s) fit together tightly, the enzyme induces the weakening of bonds within the molecules of the substrate(s), thus reducing the activation energy needed for the reaction; the reaction could be anabolic or catabolic.
Intracellular enzyme-catalysed reactions
Intracellular enzyme-catalysed reactions are metabolic reactions that take place inside the cell, and are catalysed by enzymes that are produced by free ribosomes.
Glycolysis is an intracellular metabolic pathway that takes place in the cytoplasm. It breaks down glucose into two pyruvate molecules releasing energy in the process.
Krebs cycle aka citric acid cycle is also an intracellular metabolic pathway that takes place inside the mitochondria. It oxidises acetyl-CoA to produce carbon dioxide, energy-rich molecules and electron carriers.
Extracellular enzyme-catalysed reactions
Extracellular enzyme-catalysed reactions are metabolic reactions that take place outside the cell, and are catalysed by enzymes that are produced by bound ribosomes and secreted outside the cell by exocytosis.
Digestive enzymes such as lipase, amylase, proteases are secreted extracellularly by acinar cells in the pancreas to catalyse reactions related to digestion in the gut.
cyclic metabolic patways
metabolic reactions that involve a starting compound being converted into an intermediate product, which is then further processed to regenerate the original starting compound, completing the cycle.
