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Glossary
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fats
A triglyceride, generally used for energy
storage, that is solid at room temperature; animals often use fats as storage
molecules. |
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fatty acid
A fatty acid is an organic acid (or
carboxylic acid) with a long hydrocarbon tail, either saturated or unsaturated.
Saturated fatty acids are of the form
O
HOC-R , that is, HOOC-R
where
R = CH2(CH2)nCH3
Unsaturated fatty acids are of similar form, except that one
or more alkene functional groups exist along the chain, substituting
singly-bonded
-CH2-CH2-
part of the chain with doubly-bonded
-CH=CH-
portions.
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fermentation
The processes by which organisms are able
to extract energy from glucose in the absence of oxygen. Common byproducts of
fermentation are lactic acid, and ethanol and CO2 |
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fertilization
The fusion of two gametes to produce a
zygote. |
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first law of thermodynamics
Energy can neither be created or destroyed. |
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fission
In biology, binary fission is
the asexual reproductive process used by prokaryotes.
It begins when the DNA of the cell is duplicated.
Each circular strand of DNA then attaches to the plasma membrane, which grows
inwards and splits the cell into two daughter cells.
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fluid-mosaic
model
The 'fluid mosaic' model is commonly used to describe the structure of the cell
membrane - a two-dimensional fluid of freely diffusing lipids, dotted or
embedded with proteins. Some of these proteins simply adhere to the membrane (extrinsic
proteins), while others might be said to reside within it or to span it (intrinsic
proteins or integral membrane protein). Glycoproteins have
carbohydrates attached to their extracellular domains. Cells may vary the
variety and the relative amounts of different lipids to maintain the fluidity of
their membranes despite changes in temperature. Cholesterol molecules in the
bilayer assist in regulating fluidity. |
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free energy
The term free energy
denotes that part of the total energy of a system which is available for "useful
work" and is hence not stored in heat. As a system undergoes changes, its free
energy will decrease.
G = H - TS, where G = Gibbs free
energy, H =
heat, S = entropy, and T = absolute (Kelvin) temperature.
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