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Living Environment
Living Environment / Biology Regents NY Part One
Term | Definition |
---|---|
Observation: | What is seen or measured. |
Inference: | A conclusion based on observation or evidence. |
Hypothesis: | An untested prediction. A good hypothesis states both cause and effect (“Ifthen” statement). |
Theory: | A broad explanation of natural events that is supported by strong evidence. |
Controlled Experiment: | Compares the results of an experiment between two (or more)groups. |
Control group: | “Normal” group. Should be identical to experimental group in every way except one: it does not receive the treatment (i.e.: no drug, or given the original drug or a placebo). |
Experimental Group: | Group being tested or receiving treatment. (ex: new drug) |
Placebo: | A sugar pill or other “fake” treatment give to the control group so subjects do not know which group they are in. |
Independent Variable: | Variable that is being tested (ex: new drug). In a graph the independent variable is always plotted on the X axis. |
Dependent Variable: | Variable that is measured at the end of an experiment; the results (ex: does patient get better?) The dependent variable is always plotted on the Y axis. |
homeostasis | All living things must maintain |
To maintain homeostasis, | organisms carry out the same basic life functions: nutrition,excretion, transport, respiration, growth, synthesis, regulation and synthesis. |
All life processes | make up an organism’s metabolism |
Failure to maintain homeostasis | causes disease and death |
Autotrophs | make their own food, while heterotrophs eat other organisms. |
Photosynthesis is carried | out by plants, alga and blue-green bacteria (autotrophs). |
Photosynthesis takes | the radiant energy of the sun and puts it in the bonds of sugar molecules. |
Photosynthesis occurs | mostly in the chloroplast of plant cells. |
Plants have stomates which are | small holes in their leaves that let them exchange the gasses used in photosynthesis. |
Guard cells | open and close the stomates. |
Respiration: | Organisms get energy by breaking the bonds of sugar molecules. |
A molecule of ATP | is released energy which gives all organisms their energy. |
Aerobic respiration | requires oxygen, and yields more ATP (energy) for a molecule of sugar than anaerobic (no oxygen) respiration. |
anaerobic respiration | no oxygen yields and less ATP (energy) for a molecule of sugar sugar |
forced anaerobic respiration | we produce lactic acid that damages muscles (“the burn” you feel during exercise). |
Photosynthesis and Aerobic Respiration | are opposite reactions! They are also important in cycling oxygen, carbon, hydrogen and water through the environment. |
Diffusion: | movement of molecules from high concentrations to low concentrations. Requires no energy (passive transport). |
Active Transport: | requires the use of energy, usually moving molecules from a low concentration to a high concentration (against the flow of diffusion). |
Osmosis: | the diffusion of water into or out of the cell. If water diffuses into the cell, the cell swells (get larger) and may burst. If it loses water (being put in salt water for example) it will shrivel up. |
Regulation: | coordination and control of other life functions. |
Stimulus: | a change in the environment that you respond to. |
Neuron: | is a nerve cell. |
Impulse: | is the electrical signal carried by the nerves. |
Neurotransmitters: | are chemicals that help carry the impulse. |
Hormone: | is a chemical signal secreted by different glands in the body. |
Examples of Hormones: | include insulin, adrenaline, testosterone and estrogen |
Receptor molecules: | are proteins on the surface of the cell membrane that receive signals from the nervous and endocrine system. |
Receptor molecules are needed for: | your cells to communicate and work together. |
Carbon, Hydrogen, Oxygen and Nitrogen (CHON). | are the most common elements in living things are (in order) |
Organic Compounds: | have Carbon AND Hydrogen (ex: C6H12O6 is organic, H2O, CO2,and NO3 are not). |
Organic Molecules: | are also larger than inorganic molecules. |
Carbohydrates: | are sugars and starches. |
All carbohydrates: | are made from simple sugars (like glucose) and they supply energy |
Lipids: | store energy and include fats, oils and waxes. They are made from fatty acids and glycerol. |
Proteins: | are made from amino acids |
Proteins also make: | hormones and many body an cell structures, so as far as your body is concerned, proteins are by far the most important of these three organic molecules. |
What Proteins can do is determined by: | their shape and how they fit together |
Four specific jobs of proteins: | make enzymes, make receptor molecules on the cell membrane. These are used to receive chemical messages (like hormones), make antibodies, and make hormones |
Enzymes are catalysts: | they affect the rates of chemical reactions. |
Very high temperatures cause proteins and enzymes: | to lose their shape so that they no longer work properly. This is why high fevers are dangerous. |
Lock and key model: | one type of enzyme fits one type of molecule. Change its shape and the enzyme will no longer work. |
The pH scale: | measure the strengths of acids and bases. |
A low pH: | (0-6.9) is a acid |
A high pH: | (7.1-14) is a base |
A pH of 7: | neutral (water) |
Cells: | Cells are the basic unit of life. |
All living things (except viruses): | are made of cells. |
Cell Theory: | all living things are made of cells. |
The cell membrane: | is made of lipids and proteins. It shows selective permeability |
Selective Permeability: | only some molecules can pass through it (typically small molecules like water and oxygen). |
Large molecules (like starch or protein): | need to be moved by active transport. |
ALL cells: | have a cell membrane, including those with cell walls (plants, fungi, some bacteria and protists). |
The cell wall is: | mostly for protection; the cell membrane is needed to control movement into and out of the cell. |
The animal kingdom: | is the only kingdom that completely lacks cell walls. |
Organisms are classified: | mostly by evolutionary history. Those with common ancestors are grouped together. |
Kingdoms: | are large groups of related organisms (fungi, bacteria, protists, animals, plants). |
A species: | is able to successfully reproduce amongst its members. |
A scientific name: | is made up of an organism’s Genus and species. |