molecules+of+life+glossary

This section is for you all to keep an up to date glossary of the relvant terminology we cover in this area of study. It is important that you use your own words to explain the meaning of any terms.

-Subunits are joined together by the //removal// of a water molecule
 * CONDENSATION POLYMERISATION-**A process in which monomers join together to form polymers by reacting with one another, releasing water molecules as each link forms
 * CELLS**-The smallest structural and functional unit of all organisms. They are the basic unit of life.
 * EUKARYOTES-** Organisms composed of one or more cells that contain a distinct membrane-bound nucleus and many organelles. These include protista, fungi, plants and animals
 * PROKARYOTE-** An organism with a simple cellulaer structure which lacks a membrane bound nucleus and membrane-bound organelles. These include bacteria and cyanobacteria.
 * NUCLEUS-**In a eukaryotic cell, a large organelle containing choromosomes (which control cellular activity) surrounded by by a double-layer nuclear membrane with numerous nuclear pores.
 * LIGHT MICROSCOPES-**Microscopes that only allow us to see the basic shape of cells and a few organelles
 * ELECTRON MICROSCOPES-**A microscope that allows us to see fine details of other organelles and the surface of the cell
 * SCANNING ELECTRON MICROSCOPE-**A microscope that gives us a 3D view of membrane surfaces and projections such as cilia
 * TRASMISSION ELECTRON MICROSCOPE-**A microscope that gives us a closer look at the inner structures
 * ORGANELLE-**Subcellular structures involved in specfic functions of the cell
 * NUCLEOLUS-**A granular structure in the nucleus, made up of protein and nucleic acid. It is the site of synthesis of ribosomal RNA
 * MITOCHONDRIA-**Organelle in which aerobic respiration occurs, it is a sac composed of many layers of folded membrane
 * RIBOSOMES-**Tiny organelles often attached to the endoplasmic reticulum, which is composed of RNA and protein. It is the site of protein synthesis
 * SMOOTH ENDOPLASMIC RETICULUM-**A network of membranes creating channels in the cytoplasm, from the nucleus to the cell membrane
 * ROUGH ENDOPLASMIC RETICULUM-**A network of membranes creating channels in the cytoplasm. Rough ER is studded with ribosomes
 * GOLGI COMPLEX/APPARATUS-**An organelle composed of a stack of smooth membranes (which are flattened sac-like structures) in which proteins and carbohydrates are assembled and packaged in vesicles for export from the cell
 * LYOSOMES-**Membrane-bound vesicle found in most animal cells, in which powerful enzymes break down debris and foreign microrganisms
 * VACUOLE-**Membrane-bound liquid-filled spaces within cells. Vacuoles in plant cells are usually large and are involved in storage and turgidity. In other cells, vacuoles may be involved in intracellular digestion and water balance
 * VESICLE-**Small, temporary, membrane bound structures which transport material into, out of and around the cell
 * CHOLOROPLASTS-**Green organelle containing chlorophyll, present in some plant cells, in which photosynthesis takes place. Composed of many folded layers of membrane
 * CELL WALL-**A layer of cellulose (in plants) that completely surrounds the cell membrane which provides structural support and defines the shape of cells.
 * PLASMA MEMBRANE-** Phospholipid double layer that encloses the contents of a cell and controls the movement of substances into and out of the cell.
 * HYDROPHOBIC-**'water hating'-are non-polar molecules which do not interact with water
 * HYDROPHILLIC-**'water loving' are polar molecules which readily interact with water
 * MONOSACCHARIDES-** The monomer unit of all Carbohydrates. Eg. Glucose, fructose
 * DISACCHARIDES-** Formed when two monosaccharides join together. Eg. Sucrose (glucose fructose) and maltose (glucose glucose)
 * POLYSACCHARIDES-**Complex carbohydrates composed of several hundred to several thousand monomers in chains. Used for energy storage and structural support. Eg. Cellulose
 * STARCH-**A string of glucose monomers. Used by plants for energy storage (aka AMYLOSE)
 * HYDROGEN BONDS-**Relatively weak bonds formed by the attraction between polar molecules
 * IONIC BONDS-**Chemical bonds which occur ebtween ions, particles which have an electrical charge
 * GLYCOSIDIC BONDS-**Bonds between monosaccharides
 * PHOSPOHDIESTER**-Bonds between sugar and phosphate group in polymers
 * GLYCOPROTEIN-**Molecules formed when a protein is chemically combined with a carbohydrate sub-unit
 * HETEROTROPHS-**Organisms which rely on consuming an external source of organic molecules
 * AUTOTROPHS-**Green plants and algae that are 'self-feeding' meaning they use the enegy in sunlight ti make glucose chemical energy (through photosynthesis)
 * LIGHT DEPENDENT STAGE-**The first stage in photosynthesis that involves water molecules being split by chlorophyll using light energy. This produces hydrogen, oxygen and ATP. Occurs in the grana
 * LIGHT INDEPENDENT STAGE-**AKA calvin cycle. The 2nd stage of photosynthesis inwhich ATP is used to combine the hydrogen with carbon dioxide to produce carbohydrates such as glucose. -oxygen is released as a bi-product. Occurs in the stroma
 * OBLIGATE ANAEROBES-**Some organisms such as bacteria and worms rely on anaerobic respiration and will actually die in the presence of oxygen
 * FACULTATIVE ANAEROBES-**Organisms such as bacteria, certain mollusks and yeast that switch to aerobic respiration if oxygen is present
 * GLYCOGEN-**Chemically identical to starch but has more branches of glucose chains. Also used for energy storage. (AKA animal starch)
 * BIOMACROMOLECULES** - large complex substances (large biological molecules) made by living organisms from the combining of smaller molecules.
 * ORGANIC COMPOUNDS** - complex chemical compounds that contain carbon and hydrogen (and sometimes other elements such as nitrogen, oxygen, sulphur and phosphorus). Some examples include carbohydrates, lipids, proteins and nucleic acids
 * INORGANIC COMPOUNDS** - simpler compounds that //usually// don't contain carbon. Some examples are water, oxygen and carbon dioxide.
 * MONOMERS** - the basic units that can be linked together in chains in order to form larger compounds (polymer)
 * POLYMERS** - large organic molecules composed of many smaller molecules joined together (the monomers). They are also known as macromolecules.
 * MACROMLECULES-** smaller molecules of a certain type that are combined into a larger more complex substance. They are also known as polymers and biomacromolecules. Eg. a large number of glucose molecules (monomers) are joined together to form glycogen in animal cells
 * MONOSACCHARIDES-** The monomer unit of all Carbohydrates. Eg. Glucose, fructose
 * DISACCHARIDES-** Formed when two monosaccharides join together. Eg. Sucrose (glucose fructose) and maltose (glucose glucose)
 * POLYSACCHARIDES-**Complex carbohydrates composed of several hundred to several thousand monomers in chains. Used for energy storage and structural support. Eg. Cellulose
 * CELLULOSE-** An example of a polysaccharide (a polymer of glucose) that plants use as a structural material.
 * CARBOHYDRATES-** 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 as in water (2:1).
 * AMINO ACIDS-**The monomer unit of all proteins
 * 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.
 * NUCLEOTIDES-** Monomer units of nucleic acids which are composed of three sections- phosphate group, sugar (robse) and a nitrogen containing base.
 * GENE-** the unit of heredity; a sequence of nucleotides that encodes a protein, tRNA, mRNA or rRNA molecule (i.e. covers three RNA types).
 * GENOME-**The total set of genes in an organism
 * RNA (ribonucleic acid)-** Nucleic acid made up of a sequence of ribose sugars and bases (adenine, guanine, uracil, cytosine) linked by phosphate bonds; includes mRNA, tRNA and rRna.
 * LIPIDS - '**Fatty' oranic compound, composed of mainly carbon, hydrogen and oxygen. They are not called polymers as they are not made up of repeated units.
 * TRIGLYCERIDES** - Are made up of a glycerol backbone to which three fatty acid chains are added.
 * PHOSPHOLIPID-**Fat-like substance, usually based on glycerol; are essential components of cell membranes; are involved in the uptake of fats and fatty acids from the products of digestion
 * SATURATED FATS-**Are solid at room temperature, and contain no double bonds between carbons
 * UNSATURATED FATS-**Are liquid at room temperature and have at least one double bond between carbons. //Polyunsaturated-//When there are more than one carbon-carbon double covalent bonds present
 * PLASMOLYSIS-**Occurs when plant cells ar eplaced in a hypertonic solution. It involves water diffusion out of the cell via osmosis, the vacuole will decrease in volume, thus the cell wall is rigid and does not collapse.
 * TURGOR-**A state of high internal fluid pressure that os the result of the osmotic intak of water into plant cells whose volume is limited by tge presence of a rigid cell wall
 * TRANSCRIPTION-**Process by which a base seqiuence in DNA is used toproduce a base sequence in RNA. Occurs in the nucleus
 * TRANSLATION-**Process in which the base sequence of an rRNA molecule is used to produce the amino acid sequence of a polypeptide. Occurs at the ribosomes
 * ENDOCYTOSIS -** is the process whereby cells absorb substances from the outside, by engulfing it with their cell membrane.
 * EXOCYTOSIS** - is the process of vesicles fusing with the plasma membrane to release contents into the external environment.
 * PASSIVE TRANSPORT** - the transport of matter that does not require an energy expenditure. For example, diffusion is an example of passive transport
 * CONCENTRATION GRADIENT** - the difference in molecular concentrations (eg. more "free" water molecules outside the cell, less "free" water molecules within the cell.) The larger the concentration gradient, the more rapid the rate of diffusion across the plasma membrane of a cell
 * HYPERTONIC SOLUTION** - A solution more concentrated than the inside of the cell, therefore the cell's intracellular fluid is more dilute
 * HYPOTONIC SOLUTION** - The solution outside of the cell is more dilute than the fluid within the cell, therefore the cell's intracellular fluid is more concentrated
 * ISOTONIC SOLUTION** - An equal concentration outside and inside the cell
 * ACTIVE TRANSPORT-** The movement of particles from an area of relatively low concentration to an area of high concentration against a concentration gradient.It requires the input of energy in the form of ATP
 * FACILITATED DIFFUSION-** The movement of particles from an area of relatively high concentration to an area of lower concentration through channels provided by the embedded protein molecules
 * ENZYME-**Are catalysts that speed up biochemical reactions. They control th synthesis of various biomolecules and many other cellular processes (eg. cellular respiration)
 * METABOLISM-**The overall chemical activity of cells
 * SUBSTRATE-**Molecule on which an enzyme acts
 * CATALYST-**Speeds up (catalyses) chemical reactions that would otherwise take place but more more slowly
 * ACTIVE SITE-**The part on the enzyme molecule that interacts with the substrate
 * LOCK AND KEY-**The mechanism of an enzyme binding with a substrate. Substrate moleculees must have the right shape to fit an enzyme
 * INDUCED FIT-**The mechanism of an enzyme binding with a substrate. The actual interaction between the substrate and enzyme changes the shape of the enzyme to produce the right fit.
 * ACTIVATION ENERGY-**The certain amount of energy that is required to get a reaction going
 * DENATURING-**An irreversible change in protein structure caused by excessive amounts of heat
 * INTRACELLULAR ENZYMES-**Speed up chemical reactions occuring within cells (those involved in cellular respiration)
 * EXTRACELLULAR ENZYMES-**Are secreted by cells but speed up reactions outside them (those involved in digestion)
 * SUBSTRATE SPECIFIC-**Each enzyme usually catalyses only one type of reaction
 * OPTIMUM TEMPERATURE-**The temperature at which the enzymes catalytic activity is greatest
 * CRITICAL TEMPERATURE-**When the denaturing of enzyme molecules being to occur
 * AFFINITY-**The ease with which an enzyme binds with a substrate
 * ANABOLISM-**The building of larger molecules from smaller molecules which requires energy to construct the new bonds
 * CATABOLISM-**The breakdown of macromolecules into smaller molecules, and the breaking of bonds releases energy
 * COFACTORS-**Usually small inorganic substances whichtightly bind to the enzyme and are needed o give it the right shape at the active site so that it can catalyse the necessary reaction
 * COENZYMES-**Non protein organic substances that act as carriers of substances involved in many metabolic pathways
 * DEHYDRATION (condensation)-**A process of adding subunits (monomer) to produce a macromolecule (polymer) which involves the removal of a water molecule. Process demonstrated in the production of proteins, polysaccharides and nucleic acids.
 * HYDROLYSIS-**The breakdown of macromolecules into subunits (monomers) which involves the reverse process of dehydration/condensation-the seperation of subunits of polymers involves the //addition// of a water molecule
 * PHOTOSYNTHESIS** - an endergonic process which occurs in plants (and certain bacteria), in which light energy is trapped by chlorophyll and is used to form ATP molecules. These ATP molecules are the source of energy in the process of combining carbon dioxide and hydrogen ions to form glucose. Prior to this, oxygen is released during the light dependent stage when the light energy splits the water molecules into oxygen gas and hydrogen ions.
 * MESOPHYLL CELLS** - specialised photosynthetic cells located near the upper surface of the leaf. These cells are designed to hold several hundred chloroplasts, as mesophyll cells are the site of photosynthesis.
 * THYLAKOID** - flattened membraneous sacs located inside chloroplasts (and also cyanobacteria), which function as the site for the light-dependent stage of photosynthesis. Thylakoids contain the pigment chlorophyll.
 * GRANA** - stacks of thylakoids located inside chloroplasts.
 * STROMA** - the fluid matrix that surrounds the thylakoids (grana) in the chloroplasts. It is the site for the light-independent stage of photosynthesis.
 * NADP** - An important coenzyme, functioning as a hydrogen carrier, in the light dependent stage of photosynthesis. It 'picks up' a hydrogen molecule when light splits water into oxgen gas and hydrogen ions.
 * CHEMICAL ENERGY-** The energy stored in the bonds of molecules
 * EXERGONIC REACTIONS-**Result in the net release of energy (Eg. cellular respiration)
 * ENDERGONIC REACTIONS-**Require an input of energy in order to occur (eg. photosynthesis)
 * ENERGY-**The capacity to do work
 * CHEMICAL ENERGY-**The energy stored in the bonds of molecules such as glucose
 * ATP (adenosine triphosphate)-**Molecules of ATP provide energy for immediate use by the celll produced during glycolysis and cellular respiration
 * ANAEROBIC RESPIRATION-**The breakdown of substances and consequent release of energy, without the use of oxygen, as with glycolysis followed by fermentation to alcohol and lactic acid. In most organisms, anaerobic respiration takes place only when there is not enough oxygen to sustain aerobic respiration
 * AEROBIC RESPIRATION-**Cellular respiration in which oxygen is consumed by oxidation (eg. of glucose) and carbon dioxide is produced. In most organisms, this is the usual way in which most cells obtain their energy
 * COMPETITIVE INHIBITOR-**A substance that competes for an active site on an enzyme with the usual substrate, decreasing the reaction rate, by preventing the usual substrate from binding to the active site.
 * NON-COMPETITIVE INHIBITOR-**A substance that binds to another site on the enzyme, and not to the active site. It results in a change of shape to the enzyme, which will distort the shape of the active site.
 * CHLOROPHYLL-**The green pigment present in the chloroplasts of green plants that absorbs light energy from the sun and facilitates the process of photosynthesis
 * RUBISCO-** The short name given to the enzyme ribulose bisphosphate carboxylase, which is synthesised in the chloroplasts of a plant and is used to catalyse the Calvin-Benson Cycle (Carbon Fixation) in the light-independent stage of photosynthesis in the stroma
 * FERMENTATION-**A part of the anaerobic pathway of cellular respiration. It occurs if there is a continued absence of oxygen in the cell cytosol, causing a buildup of pyruvate/pyruvic acid. Fermentation leads to pyruvate/pyruvic acid being broken down into new substances. Ethanol and carbon dioxide is produced (in some organisms such as yeast) or lactic acid is produced (in animals)
 * FIBROUS PROTEINS-**Important in cellular structure and include muscle proteins which can contract, proteins which strengthen tendones and ligaments, keratin in nails and skin and proteins which aid in blood clotting.
 * GLOBULAR PROTEINS-**Include all enzymes, antibodies, many hormones and the proteins with make up cilia and flagella.
 * PROTEOME-**Protein products of the genome
 * PROTEOMICS-**The study of proteins;their structure, unction and interactions
 * PRIMARY STRUCTURE-**The actual sequence of amino acids in a polypeptide
 * SECONDARY STRUCTURE-**Hydrogen bonds between the amino acids form pleating or coiling
 * TERTIARY STRUCTURE-**Sulphur and hydrogwn bonding between R-groups causes the protein to fold into its 3D distinctive shape (usually fibrous or globular)
 * QUANTENARY STRUCTURE-**Two or more polypeptides combining together