Respiration, Levels of Organization, and Salinity

     Organisms that cannot photosynthesize and produce their own food are called HETEROTROPHS.  Heterotrophs must obtain energy from organic matter that was produced by autotrophs.  Both autotrophs and heterotrophs perform respiration to utilize the energy stored in organic compounds by photosynthesis.  In respiration, sugars are broken down using O2, giving off CO2 and H2O as a result.



     Molecules are organized into ORGANELLES (Organelle-basic biological significant unit, in a cell or unicellular organism), which are organized into cells, which are organized into specialized tissues and organs, which are organized into organ systems in an individual.  Individuals are organized into POPULATIONS

Population



Ecosystem



(Population-a group of individuals of the same species).  Populations are organized into COMMUNITIES (Community-a community is a collection of organisms which interact with one another).  Communities of organisms make up ECOSYSTEMS (Ecosystems-include a community of organisms and the ABIOTIC (Abiotic-non-living) components of the environment in which they interact).





 

Many adaptations of marine organisms have to do with maintaining HOMEOSTASIS (Homeostasis-is the regulation of an organism's internal environment to maintain a stable, constant condition).  Regardless of external conditions like SALINITY (PPT-parts per thousand) and TEMPERATURE (degrees centigrade).



Osmosis



         Many ENZYMES (Enzymes-compound proteins or conjoined proteins that are made by living cells and act as an incendiary in specific biochemical reactions) and other organic molecules are extremely sensitive to the concentration of IONS (Ion-electrically charged atom or family of atoms created by the loss or gain of one or more electrons) in SOLUTIONS (Solution-homogeneous mixture).  Whenever the internal composition of a cell differs from that on the outside, substances tend to move in or out of the cell by DIFFUSION (Diffusion-is the process by which molecules move from areas of high to areas of low concentraion).  OSMOSIS is the diffusion of water from areas of high to areas of low concentration.  If there is more dissolved material, and therefore less water inside a cell than outside, water will move into the cell by way of osmosis.  When the outside water is more concentrated than the cell, the cell loses water by osmosis to the external environment.  Generally speaking, marine organisms live in a liquid medium that is more concentrated in ions than that of their internal environments.  Some marine organisms regulate their salt and water balance by doing nothing at all; their internal concentrations change as the salinity of water changes. 

     Such organisms are OSMOCONFORMERS.

  

Fundamentals of Biology

     Most organic molecules belong to one of these four groups: CARBOHYDRATES, PROTEINS, LIPIDS, and NUCLEIC ACIDS.  Carbohydrates are simple single-monomer sugars (monosaccharides), two-monomer sugars (disaccharides), and other multiunit sugars (polysaccharides).  Carhobydrates are simple sugars like glucose in sodas and more complex like starch in potatoes.  Proteins are functional biological molecules consisting of one or more polypeptides folded into a specific three-dimensional structure.  Different protien monomers connect to create different polymers.  Polymer strands go through a dehydration reaction to create long strands.  Long polymers go through enzymes to enter a cell and throught hydrolysis the polymer gets broken down to speed chemical reactions in a cell.  Lipids are organic compounds made of carbon and hydrogen atoms connected by nonpolar covalent bonds.  These compounds are mostly hydrophobic (not soluble in water).  This is why fat or oil sits on top of water.  Nucleic acids are a polymer made of many nucleotide monomers; these are blueprints for proteins, and through the actions of proteins; for all cellular structures and activities.  They are DNA and RNA. 

     The molecules that make up living things interact in many complex chemical systems.  Most importantly, organisms have to capture, store and use energy.  The two main ways to process energy are PHOTOSYNTHESIS and RESPIRATION. 
     Most organisms ultimately get their energy from the sun.  In photosynthesis, algae, plants and other photosynthetic organisms capture the sun's energy and use it to make glucose, a simple sugar, which is stored, utilized, and/or converted into other organic compounds.  Such organisms are called autotrophs.  Solar energy is captured by pigments such as chlorophyll and is converted into chemical energy which is then used to make glucose out of CO2 and H2O; releasing O2 as a by-product. 
     Organisms that cannot photosynthesize and produce their own food are called heterotrophs.  Heterotrophs must obtain energy from organic matter that was produced by autotrophs.  Both autotrophs and heterotrophs perform respiration to utilize the energy stored in organic compounds by photosythesis.  In respiration sugars are broken down using oxygen, giving off CO2 and water as a result.