Biology Quiz (Cells)

cohesion

refers to the attraction of molecules for other molecules of the same kind

adhesion

the process through which different molecules interact and stick to one another

surface tension

the property of a liquid’s surface that makes it act like a thin, stretched, elastic film, due to the strong attraction (cohesion) between its molecules

specific heat capacity

amount of heat energy required to raise the temperature of a unit mass

reactants

the substances that are changed during a chemical reaction

products

the substances made by a chemical reaction

activation energy

the amount of energy that needs to be absorbed for a chemical reaction to start

endothermic

chemical reactions that take in more energy than they can give

exothermic

chemical reactions that give off more energy than they can take in

element

an element is one particular type of atom

atom

an atom is the smallest basic unit of matter

compound

a substance made of atoms of different elements bonded together in a certain ratio

molecule

two or more atoms held together by covalent bonds (forms when atoms share a pair of electrons)

high energy chemical bonds

bonds between atoms C-C or C-H. these bonds are strong and release heat and light (fire) when they are broken

polar

electrons are not shared equally, so one end of a molecule is slightly positive and one end is slightly negative

nonpolar

electrons are shared equally so the molecule has no change

organic molecule

foods or materials made from foods, fuels, or materials made from fuels, bodies of living things or materials made from the bodies of living things, and high energy bonds

inorganic molecule

not high chemical energy bonds (opposite of organic molecule)

2 HNO₃

the small number that comes after a letter represents how many of that element are in the formula

2 HNO₃

the big number that comes before the formula represents how many compounds there are, and you multiply each element by that number

a water molecule is… (polar or nonpolar)

polar because the oxygen has a slightly negative charge and the hydrogen has a slightly positive charge

hydrogen bonds

positive charge from the hydrogen atom of one water molecule can attract a negative charge from another molecule

polar molecules and nonpolar molecules will often…

repel one another

universal solvent

water (more things dissolve in it than any other)

water molecules can…

be the universal solvent, cohesion, adhesion, high surface tension, high heat capacity, and changes in density

matter change in the ethanol burning lab

ethanol and oxygen in, carbon dioxide and water out C₂H₅OH + 3 O₂ —→ 2 CO₂ + 3 H₂O

energy change in the ethanol burning lab

atoms in the ethanol and oxygen are rearranged, energy gets released. High energy C-C and C-H bonds of ethanol are replaced by low energy H-O and C-O bonds in carbon dioxide and water. (chemical energy)

chemical reaction

changing substances into different substances by breaking and forming chemical bonds

bond energy

amount of energy it takes to break a bond between 2 atoms

equilibrium

when both the reactants and products are made at the same rate

example of exothermic and endothermic

exothermic = cellular respiration, endothermic = photosynthesis

cells cells build protein molecules by bonding…

amino acids together

examples of chemical reaction

light, heat, motion, chemicals

matter movement #1

where are the molecules moving? (how do molecules move to the location at the chemical change?)

matter change #2

how are atoms in molecules being rearranged into different molecules?

energy change #3

what is happening to energy? (what forms of energy are involved and what energy transformation take place during the chemical exchange?)

matter movement #4

How do molecules move away from the location of the chemical change?