Unit 1 Learning Objectives Flashcards
•Describe the four characteristics of living things
Complex, change in response to the environment, reproduce, evolve
•Define a cell
The simplest self-replicating entity that can exist as an independent unit of life
Describe the three essential features of all cells
- Store & transmit info
- Plasma membrane
- Harness energy from the environment
Explain the Central Dogma
DNA → (transcription) RNA →(translation) protein
•Define matter and element
Matter = anything that takes up space & has mass
Element = fundamental substances in nature; 94 naturally occur; cannot be broken down by chemical reactions
Know the four most abundant elements in the human body
Carbon, nitrogen, oxygen, hydrogen
Know the structure of an atom and the function of its 3 subatomic particles (protons, neutrons, electrons)
Neutron = neutral charge; contribute to mass
Proton = positive charge; contribute to mass
Electron = negative charge; negligible mass
Differentiate between an atom’s atomic number and atomic mass
Atomic number = number of protons
Atomic mass = number of protons and neutrons
Define an isotope and an ion and differentiate between the two
Isotope = two atoms of an element that differ in number of neutrons
Ion = Atoms that gain or lose an electron become charged
Explain electron orbitals
Regions of space where an electron spends most of its time
Describe the 4 types of chemical bonds used to make molecules
Covalent bond = equal sharing of electrons
Polar covalent bond = unequal sharing of electrons; depends on electronegativity of an atom
Hydrogen bond = interaction between Hydrogen and an electronegative atom; partial negative is attracted to partial positive
Ionic bond = interaction between oppositely charged ions; metal + nonmetal
Differentiate between covalent and polar covalent bonds
Covalent = equal sharing of electrons
Polar covalent = unequal sharing of electrons
Describe the properties of water that make it indispensable to life on earth
Polar molecule
Good solvent
pH of 7
Describe the interaction between the atoms of a single molecule of water, and among water molecules
Single molecule → polar covalent bonds
Multiple molecules → hydrogen bonds
Correlate water’s high specific heat with its ability to stabilize temperature fluctuations
Water changes its temperature less when it absorbs or releases a given amount of heat
High specific heat → result of hydrogen bonds
Define solution, solute, solvent, aqueous solution
Solution = a liquid that is a homogeneous mixture of substances
Solvent = the dissolving agent of a solution
Solute = the substance that is dissolved
Aqueous solution = one in which water is the solvent
Differentiate between hydrophilic and hydrophobic substances
Hydrophilic = has an affinity for water; a substance can be hydrophilic without actually dissolving
Example → cotton
Hydrophobic = does not have an affinity for water; cannot form hydrogen bonds
Example → vegetable oil
Correlate changes in hydrogen ion concentration (H+) with pH
Acid → increases (H+) and reduces pH
Base → reduces (H+) and increases pH
Describe the bonding properties of Carbon that relate to its structural diversity
Carbon atom behaves as if it has 4 unpaired electrons
Forms covalent bonds
Carbon forms a tetrahedron when covalently bound to 4 other atoms