| Question | Answer |
| Matter | anything that takes up space and
has mass |
| Atoms | the smallest chemical units of matter |
| Element | a substance that cannot be broken
down into another substance by ordinary chemical
means
An element is composed of atoms |
| Electrons | negatively charged subatomic particles circling a nucleus |
| Neutrons | uncharged particles |
| Protons | positively charged particles |
| Nucleus | structure containing neutrons and protons |
| Atomic Number | equal to the number of protons in the nucleus
It is also equal to the number of electrons
And protons if it is not an isotope |
| Atomic Mass | sum of masses of protons, neutrons, and electrons
Electrons are have very little mass |
| Element | composed of a single type of atom |
| Compound | composed of atoms of different elements; two or more atoms held together by chemical bonds
* All compounds are molecules, but not all molecules are compounds
*H2O - Compound
*N2- Molecule |
| Isotopes | Atoms of a given element can differ in the number of neutrons in their nuclei
- Stable isotopes
- Unstable isotopes |
| Radioactive isotopes | Release energy during radioactive decay |
| Valence electrons | electrons in outermost shell that interact with other atoms; combining capacity of an atom
pos - gives up electron
neg - empty spaces
stable - 8 in outer shell |
| Molecule | two or more atoms held together by chemical bonds |
| Chemical Bonds | atoms combine by sharing or transferring valence electrons |
| Electronegativity | attraction of atom for electrons
* The more electronegative an atom, the greater the pull its nucleus exerts on electrons. |
| Covalent | share electrons to complete valence shell
- Nonpolar covalent: equal sharing
- Polar covalent: not equal sharing |
| Ionic | attraction between opposite charges; Gives up or accepts electrons; Atoms have either + (cation) or - e (anion) charges; Cations n anions attract each other n form ionic bonds (no electrons shared); Typically form crystalline ionic compounds aka salts |
| Valence Bond | combining capacity of an atom
pos - gives up electron
neg - empty spaces
stable - 8 in outer shell |
| Complete Valence | Nonpolar - equal sharing
Polar- no equal sharing |
| Nonpolar Covalent Bonds | * Shared electrons spend equal amounts of time around each nucleus.
- Atoms with similar electronegativities
* Carbon atoms form four nonpolar covalent bonds with other atoms.
- Organic compounds contain carbon and hydrogen atoms. |
| Polar Covalent Bonds | * Unequal sharing of electrons due to significantly different electronegativities
* Most important polar covalent bonds involve hydrogen.
- Allow for hydrogen bonding |
| Hydrogen Bonds | *Think H2O
* Electrical attraction between partially charged H+ and full or partial negative charge on same or different molecule
* Weaker than covalent bonds but essential for life
* Help to stabilize 3-D shapes of large molecules |
| Synthesis Reactions | * Involve the formation of larger, more complex molecules
* Require energy (endothermic)
* Common type is dehydration synthesis
* Water molecule formed |
| Anabolism | All the synthesis reactions in an organism |
| Decomposition Reactions | * Break bonds within larger molecules to form smaller atoms, ions, and molecules
* Release energy (exothermic)
* Common type is hydrolysis
* Ionic components of water are added to products (H+, OH-). |
| Catabolism | All the decomposition reactions in an organism
C6H12O6 + 6 O2 → 6 H2O + 6 CO2 |
| Exchange Reactions | * Involve breaking and forming covalent bonds
* Have endothermic and exothermic steps
* Involve atoms moving from one molecule to another |
| Metabolism | Sum of all chemical reactions in an organism
A + BC → AB + C |
| Water | Most abundant
2 polar covalent bonds: Cohesion & adhesion
Excellent solvent
Remains liquid across wide range of temps
Can absorb sig amounts of heat energy wo changing temp
Participates in many chemical reactions
Density |
| Acid | * dissociates into one or more H+ and one or more anions ; 0-6.9
*HCl : H+ Cl- : Acidic |
| Base | *binds with H+ when dissolved in water; some dissociate into cations and OH– ; 7.1 - 14
NaOh : Na+ OH- : Base |
| Buffers | Keep pH from changing; prevent drastic changes in internal pH |
| Living things pH is 6.5 - 8.5 | |
| Salts | Compounds that dissociate in water into cations n anions other than H+ / OH–
Cations/anions of salts r electrolytes that:
Create electrical diff between inside/ outside of cell
Transfer electrons frm 1 location to another |
| Functional Groups | Atoms often appear in arrangements |
| Macromolecules | * large molecules used by all organisms:
1. Lipids
2. Carbohydrates
3. Proteins
4. Nucleic acids
* small building blocks that all stick together to make bigger things |
| Monomers | basic building blocks of macromolecules |
| Polymers | monomers joined together in chains |
| Lipids | * Not composed of regular subunits
* Are all hydrophobic
* Four groups:
1. Fats (triglycerides)
2. Phospholipids
3. Waxes
4. Steroids
* Waxes
Contain one long
Lack hydrophilic head
Completely insoluble in water |
| Carbohydrates | Organic molecules composed of carbon, hydrogen, and oxygen
Funct: Lterm storage of chemical energy
Part of backbones of nucleic acids
Converted to amino acids
Form cell wall
Involved in intracellular interactions between animal cells |
| Types of Carbohydrates | Monosaccharides
* come together to make polymers
Disaccharides
Polysaccharides |
| Proteins | Composed mostly of carbon, hydrogen, oxygen, nitrogen, and sulfur
Functions:
Structure
Enzymatic catalysis
Regulation
Transportation
Defense and offense |
| Amino Acids | * monomers that make up proteins
*Most organisms use only 21 amino acids in protein synthesis.
* Side groups affect how amino acids interact with one another n how a protein interacts w other molecules.
* covalent peptide bond is formed between a.a. |
| Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) | the vital genetic material of cells and viruses. |
| RNA | acts as enzyme, binds amino acids, and helps form polypeptides. |
| Nucleotides | * Monomers that make up nucleic acids
Composed of three parts:
1. Phosphate
2. Pentose sugar—either deoxyribose or ribose
3. One of five cyclic nitrogenous bases |
| Nucleic Acid | * DNA is genetic material of all organisms and of many viruses.
* Carries instructions for synthesis of RNA and proteins
* Controls synthesis of all molecules in an organism
* DNA is double stranded in most cells and viruses. |
| Adenosine triphosphate (ATP) | Energy currency of cells
Cells use ATP to carry out activities.
One nucleotide along with 3 phosphate groups makes it unstable.
Easily loses a phosphate group to become ADP (adenosine diphosphate)
Continual cycle of breakdown and regeneration |
| Which of the following structures have no electrical charge?
A. Protons
B. Electrons
C. Neutrons
D. Ions | Neutrons |
| The atomic mass of an atom most closely approximates the sum of the masses o all its:
A. protons
B. isotopes
C. electrons
D. protons and neutrons | protons and neutrons |
| One isotope of iodine differs from another in:
A. the number of protons
B. the number of electrons
C. the number of neutrons
D. atomic number | the number of neutrons |
| Which of the following is NOT an organic compound?
A. monosaccharide
B. formaldehyde
C. water
D. Steroid | Water |
| Which of the following terms most correctly describes the bonds in a molecule of water?
A. nonpolar covalent bond
B. polar covalent bond
C. ionic bond
D. hydrogen bond | Polar Covalent Bond |
| In water, cations and anions of salts dissociate crom one another and become surrounded by water molecules. In this state, the ions are also called ______________.
A. electrically negative
B. Ionically bonded
C. Electrolytes
D. Hydrogen bonds | Electrolytes |
| Which of the following can be most accurately described as a decomposition reaction?
A. C6H12O6 + 6 O2 ---> 6 H2O + 6 CO2
B. glucose + ATP ---> glucose phosphate + ADP
C. 6 H2O + 6 CO2 ---> C6H12O6 + 6 O2
D. A + BC ---> AB + C | C6H12O6 + 6 O2 ---> 6 H2O + 6 CO2 |
| Which of the following statements about a cola beverage w a pH is true?
A. relatively high concentration of hydrogen ions
B. relatively low concentration of hydrogen ions
C. equal amounts of hydroxyl and hydrogen ions
D. Cola is a buffered solution | relatively high concentration of hydrogen ions |
| Proteins are polymers of ________.
A. amino acids
B. fatty acids
C. nucleic acids
D. monosaccharides | Amino Acids |
| Which of the following are hydrophobic organic molecules?
A. proteins
B. carbohydrates
C. lipids
D. nucleic acids | Lipids |
| Th outermost electron shell of an atom is known as the ____________ shell. | Valence |
| The type of chemical bond between atoms with nearly equal electronegativities is call a(n) _______________________ bond. | Nonpolar covalent bonds |
| The principal short-term energy storage molecule in cells is ____________________. | ATP |
| Common long-term storage molecules are: | fat, wax, amylase (starch), gylocogen |
| Groups of atoms such as NH2 or OG that appear in certain common arrangements are called ______________. | functional groups |
| The reverse of dehydration synthesis is ________________. | Hydrolosis |
| Reactions that release energy are called _____________ reactions. | exothermic |
| All chemical reactions begin with reactants and result in new molecules called _____________. | products |
| The ________________ scale is a measure of the concentration of hydrogen ions in a solution. | pH |
| A nucleic acid containing the base uracil would also contain ____________ sugar. | Ribose |
