Passive transport Diffusion across a plasma membrane in which the cell expends no energy.
Penicillin the first of the so-called wonder drugs; discovered by Sir Alexander Fleming.
Parallel evolution the development of similar characteristics in organisms that are not closely related due to Adaptation to similar environments and/or strategies of life.
Peptide bond a Covalent bond that links two amino acids together to form a polypeptide chain. A covalent bond between the amine end of one amino acid and the acid end of another amino acid.
Peptides short chains of amino acids.
Perennials plants that persist in the environment for more than one year (as in the case of annuals).
Pesticides chemicals that are applied to agricultural crops or domesticated plants and which kill or inhibit growth of insects.
Paleontology the study of ancient life by collection and analysis of Fossils. paleo-, pale-, or palaeo-, palae=ancient 古生物学
Pancreas 胰 a gland in the abdominal cavity that secretes digestive Enzymes
pH
the negative logarithm of the H+ ion concentration. The pH is a measure of the acidity or basic character of a solution. p(otential of) H(ydrogen)
Phagocytes white blood cells that can engulf (by phagocytosis) and destroy microorganisms including viruses and bacteria; cells in this category include neutrophils and Monocytes.
Phosphorylation the chemical attachment of phosphorous to a molecule, usually associated with the storage of energy in the Covalent bond that is also formed. Example: attachment of the third phosphate group to ADP in the formation of the higher energy form, ATP.
Photoperiodism the ability of ain plants to sense the relative amounts of light and dark in a 24-hour period; controls the onset of flowering in many plants.
Phospholipids asymmetrical lipid molecules with a Hydrophilic head and a Hydrophobic tail. Phospholipids are the building blocks of cellular membranes.
Phagocytosis a form of Endocytosis in which white blood cells surround and engulf invading bacteria or viruses.
Phenotype the observed properties or outward appearance of a trait. The physical expression of the alleles posessed by an organism.
Parasites organisms that live in, with, or on another organism. The parasites benefit from the association without contributing to the host, usually they cause some harm to the host.
into the small intestine and also
secretes the Hormones Insulin and Glucagon 胰高血糖素into the blood, where they regulate blood glucose levels. creas＝flesh 肉
Photosynthesis the process by which plant cells use solar energy to produce ATP. The conversion of unusable sunlight energy into usable chemical energy, associated with the actions of Chlorophyll.