Exam 1 Flashcards
Inductive reasoning
Doing experiments and measurements to find information .
Deductive reasoning
Using knowledge to determine something you cannot see or measure directly.
Scientific method
An organized series of steps that allows you to gather information, organize data, and make predictions.
Scientific method steps
Form a testable hypothesis.
Design a series of experiments to test the hypothesis.
If the experiments don’t support the hypothesis, form a new one.
If many experiments support the hypothesis. A theory can be formed.
Atom
The functional unit of matter. Atoms combine to form molecules.
Element
Composed of all the same type of atoms.
Ie. Oxygen, nitrogen.
Proton
+ charge.
Found in nucleus.
Has mass.
Neutron
No charge.
Found in the nucleus.
Has a mass.
Electron
- charge.
Found in the orbitals.
Has no mass.
Isotope
An atom with the same number of protons, but a different number of neutrons than a regular atom of a particular element.
Noble gases
Elements with 8 electrons in their outer shell. They are non-reactive gases such as neon, argon, krypton, and helium.
Atomic number
Tells you the number of protons and electrons in an atom. Usually the number of neutrons equal the number of protons unless the atom is an isotope.
Atomic mass
Tells you the number of protons and neutrons and can be thought of as the “weight” of the atom. Remember, weight is a function of gravity and mass is an actual amount of something.
Covalent bond
A bond between two atoms which are share electron/s in their outer or valence shells.
Ionic bond
Atoms will lose or gain electrons and become charged due to a different number of protons and electrons. These charged atoms then stick together magnetically.
H or polar bond
Molecules with a partial positive and partial negative charge stick together.
Ex. Water
Cohesion
A property of water due to H bonds. The water molecules stick together forming drops, surface tension, and allows water to move up through plants in transpiration.
Temperature
The kinetic movement of molecules. It is measured with a thermometer and felt as heat or cold by humans.
Specific heat
The amount of heat needed to raise one gram of water one degree Celsius.
Heat of fusion
The amount of heat that must be removed to convert a liquid to a solid.
Ie. Water to ice.
Heat of vaporization
The amount of heat that must be added to convert a liquid to a gas.
Ie. Water to steam.
Ionization
When an ionic substance such as sodium chloride goes into solution in water, sodium and chloride ions form.
Hydration shell
A circle of water molecules that form around ions in an aqueous or water solution. The shell prevents the ion from rejoining the parent crystal.
Micelles
A way to dissolve lipids in fat. If the liquid, a drop of oil for example, is surrounded by phospholipids with hydrophilic heads orientated out onto the water, the micelle will be soluble.
Hydrophobic
Does not dissolve on water.
Hydrophilic
Does dissolve in water.
The pH scale
Acids range from 1 to 7, with the pH 1 being stronger than a pH 6.5 acid.
- there are more H+ at pH 1 than at 6.5
Bases range from 7 to 14, with a pH 14 base being stronger than a pH 7.5 base
- there are more OH- at pH 14 than at 6.5
pH 7 is neutral and the H+ ion conc. = the OH- ion conc.
Water
Is most dense as a liquid, least dense as a gas.
A relatively large amt of heat is needed to evaporate water. Animals take advantage of this and evaporate sweat to cool themselves.
Lipids don’t dissolve in water.
Since a. Large amt of heat must be absorbed to convert water to steam, the temp of water stays the same for some time before it comes to a boil. When the water boils, the temp will rise to 100°C.
Proteins
Amino acids are joined by peptide bonds.
A protein is a string of amino acids.
If you alter any structure level of a protein, the function of the resulting protein will also be altered.
Heat, strong acids, and bases will break the H bonds and change the structure of the protein.
The alpha helix and beta pleated sheets are both common secondary structures.
Carbohydrates
Are strings of sugar.
Starch is an energy storage form of sugar produced by plants.
Cellulose is a carbohydrate used to support young parts of plants.
Chitin forms exoskeleton.
Lipids
Are not water soluble.
Can be components of cell membranes or hormones.
They can be saturated or unsaturated.
Ie. Fats, waxes, steroids, triglycerides
DNA
Is a genetic material and is only found in the nucleus of a cell in chromosomes.
It is the instructions for protein synthesis and directs cell division.
DNA transmits genetic information to offspring.
DNA is double stranded and forms a helix.
It contains the bases Adenine, Guanine, Cytosine, Thymine.
RNA
Is used in protein synthesis.
It is formed by copying DNA in the nucleus, and then moves out of the cytoplasm.
It is single stranded.
RNA contains the bases Adenine, Guanine, Cytosine, Uracil.
There are 3 types, mRNA, tRNA, and rRNA
Enzymes
Are composed of protein.
Strong acids, bases, and heat denature enzymes by breaking the H bonds that give them their 3-D shape.
Cold reduce the speed at which enzymes work, but will not denature them.
Some enzymes need a coenzyme or nonprotein helper molecule to make them functional.
Molecules which block the active active site are called inhibitors.
Endergonic reactions
Need an addition of heat or energy for the reaction to go. In living systems enzymes are used.
Exergonic reactions
Do not need the addition of heat or enzymes and will go on their own. Some exergonic reactions even release small amts of heat.
Entropy
Is a measure of the randomness or disorder of a system. Cells and living things must have a low amt of entropy to stay alive. Low entropy, or high organization, requires large amts of energy.
