Vocab Chapter 1 Flashcards
Cell
The smallest structural and functional unit of which all living things are built
Cell theory
States that all organisms are composed of cells (and their products), all cells come from pre-existing cells and the cell is the smallest living organisational unit
cytoplasm
all the contents of the cell except the nucleus
Plasma membrane
Phospholipid double layer that encloses the contents of a cell and controls the movement of substances into and out of the cell
DNA
A nucleic acid made up of a sequence of deoxyribose sugars and bases (adenine, cytosine, guanine, and thymine) linked by phosphate bonds. it is the carrier of genetic information in all cellular organisms and most viruses; found in chromosomes (and mitochondria and chloroplasts)
Organelle
Subcellular structure found in eukaryotic cells which are involved in specific functions of the cell
Prokaryote
An organism with a simple cellular structure lacking most organelles
Eukaryote
Organism composed of one or more cells that contain distinct membrane-bound nuclei and many organelles; includes protists, fungi, plants and animals
Organic Compounds
any of the complex molecules containing carbon that occur in living organisms; for example, proteins, carbohydrates and lipids
inorganic compound
all compounds other than organic compounds; for example, water, carbon dioxide, calcium carbonate (lime)
Hydrophobic
molecules and compounds that repel water
Hydrophilic
Polar ions and molecules that dissolve easily in water
pH
A measure of acidity or alkalinity, measured on a scale of 0 (most acid) to 14 (most alkaline). One unit on a pH scale means a tenfold difference in acidity or alkalinity
ATP
Adenosine triphosphate. Molecules of ATP provide energy for immediate use by the cell; produced during glycolysis and cellular respiration
Biomacromolecules
Large organic molecules formed by joining together many smaller units (monomers) to form a chain or polymer, for example polysaccharides, nucleic acids and proteins
Polymer
Large organic molecules, formed by joining together many smaller moleules (also known as macromolecules)
Carbohydrate
Organic compound, such as sugars, starch and cellulose, that is made of carbon, hydrogen and oxygen, the hydrogen and oxygen are present in the same proportion to water (2:1)
Protein
Functional molecule that is composed of one or more polypeptides, which are linear sequences of amino acids.
Protein Structure
Four levels: primary (the linear sequence of amino acids, secondary (pleating or coiling of the polypeptide chain), tertiary (subsequent three dimensional folding of the polypeptide) and quarternary (aggregation of more than one polypeptide)
Amino Acid
Compound that is the building block of polypeptides. The key chemical features are the presence of an amino (NH2) group anf a carboxyl (COOH) group at opposite ends of the molecule
polypeptide
A protein consisting of a number of amino acids linked together by peptide bonds. an amino group is found at one end of a polypeptide, a carboxyl group at the other.
nucleic acid
the genetic material of all organisms; molecule in which information is stored that determines features of an organism and controls cellular activities
RNA
ribonucleic acid, Nucleic acid made up of a sequence of ribose sugars and bases (adenine, cytosine, guanine and uracil) linked by phosphate bonds; includes mRNA tRNA and rRNA
nucleotide
A molecule consisting of a 5-carbon sugar (ribose or deoxyribose), a nitrogenous base (purine or pyrimidine) and a phosphate group; the main building blocks of nucleic acids
gene
the unit of heredity; a sequence of nucleotides that encodes a protein, tRNA, mRNA or rRNA molecule (i.e. covers three RNA types
Chromosome
Dark staining thread-like structure in the nucleus; composed of DNA and proteins and contains genetic information in the form of genes arranged in a linear order. Found in constant numbers in body cells of organisms of a particular species
Lipid
‘Fatty’ organic compound including fats and oils which is composed mainly of carbon, hydrogen and oxygen. lipids have proportionally less oxygen than carbohydrates, and may contain other elements.
Phospholipid
Fat-like substance, usually based on glycerol; phospholipids are essential components of cell membranes; are involved in the uptake of fats and fatty acids from the products of digestion
omega-3 (or -6) fatty acid
Fatty acid with a double bond (and kink) between the third and fourth (or sixth and seventh) carbon from the omega end
Phospholipid
fat-like substance, usually based on glycerol; phospholipids are sessential components of cell membranes; are involved in the uptake of fats and fatty acids from the product of digestion.
fluid-mosaic model
in relation to cell membranes - fluid because of the lateral movement of lipid molecules and mosaic because of the irregular location of proteins in the membrane
diffusion
passive movement of a solute from a region of higher concentration to a region of low concentration
concentration gradient
difference in concentration of a solute between one region and another, for example across a membrane
Osmosis
Passive diffusion of free molecules across a differentially permeable from a solution in which there are more free water molecules (a dilute solution) to a solution in which there are fewer free water molecules (a concentrated solution).
facilitated diffusion
passive diffusion through selective protein channels in membranes
active transport
movement of substances across membranes that requires the expenditure of energy; occurs through selective protein channels
