exam #1 Flashcards
define life
the condition which distinguish animals, plant, fungi, protist and bacteria from inorganic objects and dead organisms
characteristics of living systems
- cellular organization2. ordered complexity3. response to stimuli4. growth through metabolism5. homeostasis6. development7. reproduction8. evolution
how is the scientific method used to study living systems?
- make observations2. hypothesis construction3. hypothesis testing4. data analysis5. conclusion6. repeat
elements found in living systems
-C, O, H, N -Na, Cl, P, K, S, Fe, Mg - trace amounts
covalent bonds
-strong bonds (single, double, triple)-occur when elements share electrons-form discrete molecules-occur WITHIN molecules
hydrogen bonds
-weak association/weaker than covalent-easy to break and reform-involve 2 polar molecules-occur BETWEEN molecules
ionic bonds
-opposite charges attract-compounds are electrically neutral -atoms not paired, but associate with all other opposite charges in the vicinity-water disrupts these bonds by separating the ions or dissolving the crystals
non-polar
electrons shared equally
polar
electrons spend more time in part of the molecule
cohesive
attraction between water molecules
adhesive
attraction with other polar molecules
impact of temperature on the properties of water
-high specific heat-high heat of vaporization (vaporizes when all hydrogen bonds are broken)-low density of ice
solution = – + –
solvent + solute
substances that can form hydrogen bonds in water are those substances that can form hydrogen bonds with —
water
can things that aren’t polar still dissolve?
yes, but they have to form hydrogen shells
hydrophobic
water hating
hydrophilic
water loving
definition of a cell
smallest unit of life
cell theory
- organisms are composed of one or more cells2. cells are the smallest living thing3. cells arise from the division of a previously existing cell
characteristcs common to all cells
- genetic material - DNA2. cytoplasm3. plasma membrane
what limits cell size?
transportation… the smaller the cell the easier it is to transport things from place to place
diffusion
solvent moves by concentration gradient (area of high concentration to an area of low concentration)
biomolecules
-lipids-proteins-carbohydrates-nucleic acid
properties of lipids
-non-polar-high proportion of hydrogen-carbon bonds-hydrophobic